Chapter 23: Application Programming Interfaces (APIs) (v0.23)

Dockerfile

@@ -0,0 +1,23 @@
+FROM python:slim
+
+RUN useradd microblog
+
+WORKDIR /home/microblog
+
+COPY requirements.txt requirements.txt
+RUN python -m venv venv
+RUN venv/bin/pip install -r requirements.txt
+RUN venv/bin/pip install gunicorn pymysql cryptography
+
+COPY app app
+COPY migrations migrations
+COPY microblog.py config.py boot.sh ./
+RUN chmod a+x boot.sh
+
+ENV FLASK_APP microblog.py
+
+RUN chown -R microblog:microblog ./
+USER microblog
+
+EXPOSE 5000
+ENTRYPOINT ["./boot.sh"]

Procfile

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+web: flask db upgrade; flask translate compile; gunicorn microblog:app
+worker: rq worker microblog-tasks

Vagrantfile

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+Vagrant.configure("2") do |config|
+  config.vm.box = "ubuntu/focal64"
+  config.vm.network "private_network", ip: "192.168.33.10"
+  config.vm.provider "virtualbox" do |vb|
+    vb.memory = "2048"
+  end
+end

app/__init__.py

@@ -1,7 +1,99 @@
-from flask import Flask
+import logging
+from logging.handlers import SMTPHandler, RotatingFileHandler
+import os
+from flask import Flask, request, current_app
+from flask_sqlalchemy import SQLAlchemy
+from flask_migrate import Migrate
+from flask_login import LoginManager
+from flask_mail import Mail
+from flask_bootstrap import Bootstrap
+from flask_moment import Moment
+from flask_babel import Babel, lazy_gettext as _l
+from elasticsearch import Elasticsearch
+from redis import Redis
+import rq
 from config import Config
 
-app = Flask(__name__)
-app.config.from_object(Config)
+db = SQLAlchemy()
+migrate = Migrate()
+login = LoginManager()
+login.login_view = 'auth.login'
+login.login_message = _l('Please log in to access this page.')
+mail = Mail()
+bootstrap = Bootstrap()
+moment = Moment()
+babel = Babel()
 
-from app import routes
+
+def create_app(config_class=Config):
+    app = Flask(__name__)
+    app.config.from_object(config_class)
+
+    db.init_app(app)
+    migrate.init_app(app, db)
+    login.init_app(app)
+    mail.init_app(app)
+    bootstrap.init_app(app)
+    moment.init_app(app)
+    babel.init_app(app)
+    app.elasticsearch = Elasticsearch([app.config['ELASTICSEARCH_URL']]) \
+        if app.config['ELASTICSEARCH_URL'] else None
+    app.redis = Redis.from_url(app.config['REDIS_URL'])
+    app.task_queue = rq.Queue('microblog-tasks', connection=app.redis)
+
+    from app.errors import bp as errors_bp
+    app.register_blueprint(errors_bp)
+
+    from app.auth import bp as auth_bp
+    app.register_blueprint(auth_bp, url_prefix='/auth')
+
+    from app.main import bp as main_bp
+    app.register_blueprint(main_bp)
+
+    from app.api import bp as api_bp
+    app.register_blueprint(api_bp, url_prefix='/api')
+
+    if not app.debug and not app.testing:
+        if app.config['MAIL_SERVER']:
+            auth = None
+            if app.config['MAIL_USERNAME'] or app.config['MAIL_PASSWORD']:
+                auth = (app.config['MAIL_USERNAME'],
+                        app.config['MAIL_PASSWORD'])
+            secure = None
+            if app.config['MAIL_USE_TLS']:
+                secure = ()
+            mail_handler = SMTPHandler(
+                mailhost=(app.config['MAIL_SERVER'], app.config['MAIL_PORT']),
+                fromaddr='no-reply@' + app.config['MAIL_SERVER'],
+                toaddrs=app.config['ADMINS'], subject='Microblog Failure',
+                credentials=auth, secure=secure)
+            mail_handler.setLevel(logging.ERROR)
+            app.logger.addHandler(mail_handler)
+
+        if app.config['LOG_TO_STDOUT']:
+            stream_handler = logging.StreamHandler()
+            stream_handler.setLevel(logging.INFO)
+            app.logger.addHandler(stream_handler)
+        else:
+            if not os.path.exists('logs'):
+                os.mkdir('logs')
+            file_handler = RotatingFileHandler('logs/microblog.log',
+                                               maxBytes=10240, backupCount=10)
+            file_handler.setFormatter(logging.Formatter(
+                '%(asctime)s %(levelname)s: %(message)s '
+                '[in %(pathname)s:%(lineno)d]'))
+            file_handler.setLevel(logging.INFO)
+            app.logger.addHandler(file_handler)
+
+        app.logger.setLevel(logging.INFO)
+        app.logger.info('Microblog startup')
+
+    return app
+
+
+@babel.localeselector
+def get_locale():
+    return request.accept_languages.best_match(current_app.config['LANGUAGES'])
+
+
+from app import models

app/api/__init__.py

@@ -0,0 +1,5 @@
+from flask import Blueprint
+
+bp = Blueprint('api', __name__)
+
+from app.api import users, errors, tokens

app/api/auth.py

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+from flask_httpauth import HTTPBasicAuth, HTTPTokenAuth
+from app.models import User
+from app.api.errors import error_response
+
+basic_auth = HTTPBasicAuth()
+token_auth = HTTPTokenAuth()
+
+
+@basic_auth.verify_password
+def verify_password(username, password):
+    user = User.query.filter_by(username=username).first()
+    if user and user.check_password(password):
+        return user
+
+
+@basic_auth.error_handler
+def basic_auth_error(status):
+    return error_response(status)
+
+
+@token_auth.verify_token
+def verify_token(token):
+    return User.check_token(token) if token else None
+
+
+@token_auth.error_handler
+def token_auth_error(status):
+    return error_response(status)

app/api/errors.py

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+from flask import jsonify
+from werkzeug.http import HTTP_STATUS_CODES
+
+
+def error_response(status_code, message=None):
+    payload = {'error': HTTP_STATUS_CODES.get(status_code, 'Unknown error')}
+    if message:
+        payload['message'] = message
+    response = jsonify(payload)
+    response.status_code = status_code
+    return response
+
+
+def bad_request(message):
+    return error_response(400, message)

app/api/tokens.py

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+from flask import jsonify
+from app import db
+from app.api import bp
+from app.api.auth import basic_auth, token_auth
+
+
+@bp.route('/tokens', methods=['POST'])
+@basic_auth.login_required
+def get_token():
+    token = basic_auth.current_user().get_token()
+    db.session.commit()
+    return jsonify({'token': token})
+
+
+@bp.route('/tokens', methods=['DELETE'])
+@token_auth.login_required
+def revoke_token():
+    token_auth.current_user().revoke_token()
+    db.session.commit()
+    return '', 204

app/api/users.py

@@ -0,0 +1,80 @@
+from flask import jsonify, request, url_for, abort
+from app import db
+from app.models import User
+from app.api import bp
+from app.api.auth import token_auth
+from app.api.errors import bad_request
+
+
+@bp.route('/users/<int:id>', methods=['GET'])
+@token_auth.login_required
+def get_user(id):
+    return jsonify(User.query.get_or_404(id).to_dict())
+
+
+@bp.route('/users', methods=['GET'])
+@token_auth.login_required
+def get_users():
+    page = request.args.get('page', 1, type=int)
+    per_page = min(request.args.get('per_page', 10, type=int), 100)
+    data = User.to_collection_dict(User.query, page, per_page, 'api.get_users')
+    return jsonify(data)
+
+
+@bp.route('/users/<int:id>/followers', methods=['GET'])
+@token_auth.login_required
+def get_followers(id):
+    user = User.query.get_or_404(id)
+    page = request.args.get('page', 1, type=int)
+    per_page = min(request.args.get('per_page', 10, type=int), 100)
+    data = User.to_collection_dict(user.followers, page, per_page,
+                                   'api.get_followers', id=id)
+    return jsonify(data)
+
+
+@bp.route('/users/<int:id>/followed', methods=['GET'])
+@token_auth.login_required
+def get_followed(id):
+    user = User.query.get_or_404(id)
+    page = request.args.get('page', 1, type=int)
+    per_page = min(request.args.get('per_page', 10, type=int), 100)
+    data = User.to_collection_dict(user.followed, page, per_page,
+                                   'api.get_followed', id=id)
+    return jsonify(data)
+
+
+@bp.route('/users', methods=['POST'])
+def create_user():
+    data = request.get_json() or {}
+    if 'username' not in data or 'email' not in data or 'password' not in data:
+        return bad_request('must include username, email and password fields')
+    if User.query.filter_by(username=data['username']).first():
+        return bad_request('please use a different username')
+    if User.query.filter_by(email=data['email']).first():
+        return bad_request('please use a different email address')
+    user = User()
+    user.from_dict(data, new_user=True)
+    db.session.add(user)
+    db.session.commit()
+    response = jsonify(user.to_dict())
+    response.status_code = 201
+    response.headers['Location'] = url_for('api.get_user', id=user.id)
+    return response
+
+
+@bp.route('/users/<int:id>', methods=['PUT'])
+@token_auth.login_required
+def update_user(id):
+    if token_auth.current_user().id != id:
+        abort(403)
+    user = User.query.get_or_404(id)
+    data = request.get_json() or {}
+    if 'username' in data and data['username'] != user.username and \
+            User.query.filter_by(username=data['username']).first():
+        return bad_request('please use a different username')
+    if 'email' in data and data['email'] != user.email and \
+            User.query.filter_by(email=data['email']).first():
+        return bad_request('please use a different email address')
+    user.from_dict(data, new_user=False)
+    db.session.commit()
+    return jsonify(user.to_dict())

app/auth/__init__.py

@@ -0,0 +1,5 @@
+from flask import Blueprint
+
+bp = Blueprint('auth', __name__)
+
+from app.auth import routes

app/auth/email.py

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+from flask import render_template, current_app
+from flask_babel import _
+from app.email import send_email
+
+
+def send_password_reset_email(user):
+    token = user.get_reset_password_token()
+    send_email(_('[Microblog] Reset Your Password'),
+               sender=current_app.config['ADMINS'][0],
+               recipients=[user.email],
+               text_body=render_template('email/reset_password.txt',
+                                         user=user, token=token),
+               html_body=render_template('email/reset_password.html',
+                                         user=user, token=token))

app/auth/forms.py

@@ -0,0 +1,45 @@
+from flask_wtf import FlaskForm
+from wtforms import StringField, PasswordField, BooleanField, SubmitField
+from wtforms.validators import ValidationError, DataRequired, Email, EqualTo
+from flask_babel import _, lazy_gettext as _l
+from app.models import User
+
+
+class LoginForm(FlaskForm):
+    username = StringField(_l('Username'), validators=[DataRequired()])
+    password = PasswordField(_l('Password'), validators=[DataRequired()])
+    remember_me = BooleanField(_l('Remember Me'))
+    submit = SubmitField(_l('Sign In'))
+
+
+class RegistrationForm(FlaskForm):
+    username = StringField(_l('Username'), validators=[DataRequired()])
+    email = StringField(_l('Email'), validators=[DataRequired(), Email()])
+    password = PasswordField(_l('Password'), validators=[DataRequired()])
+    password2 = PasswordField(
+        _l('Repeat Password'), validators=[DataRequired(),
+                                           EqualTo('password')])
+    submit = SubmitField(_l('Register'))
+
+    def validate_username(self, username):
+        user = User.query.filter_by(username=username.data).first()
+        if user is not None:
+            raise ValidationError(_('Please use a different username.'))
+
+    def validate_email(self, email):
+        user = User.query.filter_by(email=email.data).first()
+        if user is not None:
+            raise ValidationError(_('Please use a different email address.'))
+
+
+class ResetPasswordRequestForm(FlaskForm):
+    email = StringField(_l('Email'), validators=[DataRequired(), Email()])
+    submit = SubmitField(_l('Request Password Reset'))
+
+
+class ResetPasswordForm(FlaskForm):
+    password = PasswordField(_l('Password'), validators=[DataRequired()])
+    password2 = PasswordField(
+        _l('Repeat Password'), validators=[DataRequired(),
+                                           EqualTo('password')])
+    submit = SubmitField(_l('Request Password Reset'))

app/auth/routes.py

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+from flask import render_template, redirect, url_for, flash, request
+from werkzeug.urls import url_parse
+from flask_login import login_user, logout_user, current_user
+from flask_babel import _
+from app import db
+from app.auth import bp
+from app.auth.forms import LoginForm, RegistrationForm, \
+    ResetPasswordRequestForm, ResetPasswordForm
+from app.models import User
+from app.auth.email import send_password_reset_email
+
+
+@bp.route('/login', methods=['GET', 'POST'])
+def login():
+    if current_user.is_authenticated:
+        return redirect(url_for('main.index'))
+    form = LoginForm()
+    if form.validate_on_submit():
+        user = User.query.filter_by(username=form.username.data).first()
+        if user is None or not user.check_password(form.password.data):
+            flash(_('Invalid username or password'))
+            return redirect(url_for('auth.login'))
+        login_user(user, remember=form.remember_me.data)
+        next_page = request.args.get('next')
+        if not next_page or url_parse(next_page).netloc != '':
+            next_page = url_for('main.index')
+        return redirect(next_page)
+    return render_template('auth/login.html', title=_('Sign In'), form=form)
+
+
+@bp.route('/logout')
+def logout():
+    logout_user()
+    return redirect(url_for('main.index'))
+
+
+@bp.route('/register', methods=['GET', 'POST'])
+def register():
+    if current_user.is_authenticated:
+        return redirect(url_for('main.index'))
+    form = RegistrationForm()
+    if form.validate_on_submit():
+        user = User(username=form.username.data, email=form.email.data)
+        user.set_password(form.password.data)
+        db.session.add(user)
+        db.session.commit()
+        flash(_('Congratulations, you are now a registered user!'))
+        return redirect(url_for('auth.login'))
+    return render_template('auth/register.html', title=_('Register'),
+                           form=form)
+
+
+@bp.route('/reset_password_request', methods=['GET', 'POST'])
+def reset_password_request():
+    if current_user.is_authenticated:
+        return redirect(url_for('main.index'))
+    form = ResetPasswordRequestForm()
+    if form.validate_on_submit():
+        user = User.query.filter_by(email=form.email.data).first()
+        if user:
+            send_password_reset_email(user)
+        flash(
+            _('Check your email for the instructions to reset your password'))
+        return redirect(url_for('auth.login'))
+    return render_template('auth/reset_password_request.html',
+                           title=_('Reset Password'), form=form)
+
+
+@bp.route('/reset_password/<token>', methods=['GET', 'POST'])
+def reset_password(token):
+    if current_user.is_authenticated:
+        return redirect(url_for('main.index'))
+    user = User.verify_reset_password_token(token)
+    if not user:
+        return redirect(url_for('main.index'))
+    form = ResetPasswordForm()
+    if form.validate_on_submit():
+        user.set_password(form.password.data)
+        db.session.commit()
+        flash(_('Your password has been reset.'))
+        return redirect(url_for('auth.login'))
+    return render_template('auth/reset_password.html', form=form)

app/cli.py

@@ -0,0 +1,35 @@
+import os
+import click
+
+
+def register(app):
+    @app.cli.group()
+    def translate():
+        """Translation and localization commands."""
+        pass
+
+    @translate.command()
+    @click.argument('lang')
+    def init(lang):
+        """Initialize a new language."""
+        if os.system('pybabel extract -F babel.cfg -k _l -o messages.pot .'):
+            raise RuntimeError('extract command failed')
+        if os.system(
+                'pybabel init -i messages.pot -d app/translations -l ' + lang):
+            raise RuntimeError('init command failed')
+        os.remove('messages.pot')
+
+    @translate.command()
+    def update():
+        """Update all languages."""
+        if os.system('pybabel extract -F babel.cfg -k _l -o messages.pot .'):
+            raise RuntimeError('extract command failed')
+        if os.system('pybabel update -i messages.pot -d app/translations'):
+            raise RuntimeError('update command failed')
+        os.remove('messages.pot')
+
+    @translate.command()
+    def compile():
+        """Compile all languages."""
+        if os.system('pybabel compile -d app/translations'):
+            raise RuntimeError('compile command failed')

app/email.py

@@ -0,0 +1,24 @@
+from threading import Thread
+from flask import current_app
+from flask_mail import Message
+from app import mail
+
+
+def send_async_email(app, msg):
+    with app.app_context():
+        mail.send(msg)
+
+
+def send_email(subject, sender, recipients, text_body, html_body,
+               attachments=None, sync=False):
+    msg = Message(subject, sender=sender, recipients=recipients)
+    msg.body = text_body
+    msg.html = html_body
+    if attachments:
+        for attachment in attachments:
+            msg.attach(*attachment)
+    if sync:
+        mail.send(msg)
+    else:
+        Thread(target=send_async_email,
+            args=(current_app._get_current_object(), msg)).start()

app/errors/__init__.py

@@ -0,0 +1,5 @@
+from flask import Blueprint
+
+bp = Blueprint('errors', __name__)
+
+from app.errors import handlers

app/errors/handlers.py

@@ -0,0 +1,24 @@
+from flask import render_template, request
+from app import db
+from app.errors import bp
+from app.api.errors import error_response as api_error_response
+
+
+def wants_json_response():
+    return request.accept_mimetypes['application/json'] >= \
+        request.accept_mimetypes['text/html']
+
+
+@bp.app_errorhandler(404)
+def not_found_error(error):
+    if wants_json_response():
+        return api_error_response(404)
+    return render_template('errors/404.html'), 404
+
+
+@bp.app_errorhandler(500)
+def internal_error(error):
+    db.session.rollback()
+    if wants_json_response():
+        return api_error_response(500)
+    return render_template('errors/500.html'), 500

app/forms.py

@@ -1,10 +0,0 @@
-from flask_wtf import FlaskForm
-from wtforms import StringField, PasswordField, BooleanField, SubmitField
-from wtforms.validators import DataRequired
-
-
-class LoginForm(FlaskForm):
-    username = StringField('Username', validators=[DataRequired()])
-    password = PasswordField('Password', validators=[DataRequired()])
-    remember_me = BooleanField('Remember Me')
-    submit = SubmitField('Sign In')

app/main/__init__.py

@@ -0,0 +1,5 @@
+from flask import Blueprint
+
+bp = Blueprint('main', __name__)
+
+from app.main import routes

app/main/forms.py

@@ -0,0 +1,49 @@
+from flask import request
+from flask_wtf import FlaskForm
+from wtforms import StringField, SubmitField, TextAreaField
+from wtforms.validators import ValidationError, DataRequired, Length
+from flask_babel import _, lazy_gettext as _l
+from app.models import User
+
+
+class EditProfileForm(FlaskForm):
+    username = StringField(_l('Username'), validators=[DataRequired()])
+    about_me = TextAreaField(_l('About me'),
+                             validators=[Length(min=0, max=140)])
+    submit = SubmitField(_l('Submit'))
+
+    def __init__(self, original_username, *args, **kwargs):
+        super(EditProfileForm, self).__init__(*args, **kwargs)
+        self.original_username = original_username
+
+    def validate_username(self, username):
+        if username.data != self.original_username:
+            user = User.query.filter_by(username=self.username.data).first()
+            if user is not None:
+                raise ValidationError(_('Please use a different username.'))
+
+
+class EmptyForm(FlaskForm):
+    submit = SubmitField('Submit')
+
+
+class PostForm(FlaskForm):
+    post = TextAreaField(_l('Say something'), validators=[DataRequired()])
+    submit = SubmitField(_l('Submit'))
+
+
+class SearchForm(FlaskForm):
+    q = StringField(_l('Search'), validators=[DataRequired()])
+
+    def __init__(self, *args, **kwargs):
+        if 'formdata' not in kwargs:
+            kwargs['formdata'] = request.args
+        if 'meta' not in kwargs:
+            kwargs['meta'] = {'csrf': False}
+        super(SearchForm, self).__init__(*args, **kwargs)
+
+
+class MessageForm(FlaskForm):
+    message = TextAreaField(_l('Message'), validators=[
+        DataRequired(), Length(min=1, max=140)])
+    submit = SubmitField(_l('Submit'))

app/main/routes.py

@@ -0,0 +1,232 @@
+from datetime import datetime
+from flask import render_template, flash, redirect, url_for, request, g, \
+    jsonify, current_app
+from flask_login import current_user, login_required
+from flask_babel import _, get_locale
+from langdetect import detect, LangDetectException
+from app import db
+from app.main.forms import EditProfileForm, EmptyForm, PostForm, SearchForm, \
+    MessageForm
+from app.models import User, Post, Message, Notification
+from app.translate import translate
+from app.main import bp
+
+
+@bp.before_app_request
+def before_request():
+    if current_user.is_authenticated:
+        current_user.last_seen = datetime.utcnow()
+        db.session.commit()
+        g.search_form = SearchForm()
+    g.locale = str(get_locale())
+
+
+@bp.route('/', methods=['GET', 'POST'])
+@bp.route('/index', methods=['GET', 'POST'])
+@login_required
+def index():
+    form = PostForm()
+    if form.validate_on_submit():
+        try:
+            language = detect(form.post.data)
+        except LangDetectException:
+            language = ''
+        post = Post(body=form.post.data, author=current_user,
+                    language=language)
+        db.session.add(post)
+        db.session.commit()
+        flash(_('Your post is now live!'))
+        return redirect(url_for('main.index'))
+    page = request.args.get('page', 1, type=int)
+    posts = current_user.followed_posts().paginate(
+        page=page, per_page=current_app.config['POSTS_PER_PAGE'],
+        error_out=False)
+    next_url = url_for('main.index', page=posts.next_num) \
+        if posts.has_next else None
+    prev_url = url_for('main.index', page=posts.prev_num) \
+        if posts.has_prev else None
+    return render_template('index.html', title=_('Home'), form=form,
+                           posts=posts.items, next_url=next_url,
+                           prev_url=prev_url)
+
+
+@bp.route('/explore')
+@login_required
+def explore():
+    page = request.args.get('page', 1, type=int)
+    posts = Post.query.order_by(Post.timestamp.desc()).paginate(
+        page=page, per_page=current_app.config['POSTS_PER_PAGE'],
+        error_out=False)
+    next_url = url_for('main.explore', page=posts.next_num) \
+        if posts.has_next else None
+    prev_url = url_for('main.explore', page=posts.prev_num) \
+        if posts.has_prev else None
+    return render_template('index.html', title=_('Explore'),
+                           posts=posts.items, next_url=next_url,
+                           prev_url=prev_url)
+
+
+@bp.route('/user/<username>')
+@login_required
+def user(username):
+    user = User.query.filter_by(username=username).first_or_404()
+    page = request.args.get('page', 1, type=int)
+    posts = user.posts.order_by(Post.timestamp.desc()).paginate(
+        page=page, per_page=current_app.config['POSTS_PER_PAGE'],
+        error_out=False)
+    next_url = url_for('main.user', username=user.username,
+                       page=posts.next_num) if posts.has_next else None
+    prev_url = url_for('main.user', username=user.username,
+                       page=posts.prev_num) if posts.has_prev else None
+    form = EmptyForm()
+    return render_template('user.html', user=user, posts=posts.items,
+                           next_url=next_url, prev_url=prev_url, form=form)
+
+
+@bp.route('/user/<username>/popup')
+@login_required
+def user_popup(username):
+    user = User.query.filter_by(username=username).first_or_404()
+    form = EmptyForm()
+    return render_template('user_popup.html', user=user, form=form)
+
+
+@bp.route('/edit_profile', methods=['GET', 'POST'])
+@login_required
+def edit_profile():
+    form = EditProfileForm(current_user.username)
+    if form.validate_on_submit():
+        current_user.username = form.username.data
+        current_user.about_me = form.about_me.data
+        db.session.commit()
+        flash(_('Your changes have been saved.'))
+        return redirect(url_for('main.edit_profile'))
+    elif request.method == 'GET':
+        form.username.data = current_user.username
+        form.about_me.data = current_user.about_me
+    return render_template('edit_profile.html', title=_('Edit Profile'),
+                           form=form)
+
+
+@bp.route('/follow/<username>', methods=['POST'])
+@login_required
+def follow(username):
+    form = EmptyForm()
+    if form.validate_on_submit():
+        user = User.query.filter_by(username=username).first()
+        if user is None:
+            flash(_('User %(username)s not found.', username=username))
+            return redirect(url_for('main.index'))
+        if user == current_user:
+            flash(_('You cannot follow yourself!'))
+            return redirect(url_for('main.user', username=username))
+        current_user.follow(user)
+        db.session.commit()
+        flash(_('You are following %(username)s!', username=username))
+        return redirect(url_for('main.user', username=username))
+    else:
+        return redirect(url_for('main.index'))
+
+
+@bp.route('/unfollow/<username>', methods=['POST'])
+@login_required
+def unfollow(username):
+    form = EmptyForm()
+    if form.validate_on_submit():
+        user = User.query.filter_by(username=username).first()
+        if user is None:
+            flash(_('User %(username)s not found.', username=username))
+            return redirect(url_for('main.index'))
+        if user == current_user:
+            flash(_('You cannot unfollow yourself!'))
+            return redirect(url_for('main.user', username=username))
+        current_user.unfollow(user)
+        db.session.commit()
+        flash(_('You are not following %(username)s.', username=username))
+        return redirect(url_for('main.user', username=username))
+    else:
+        return redirect(url_for('main.index'))
+
+
+@bp.route('/translate', methods=['POST'])
+@login_required
+def translate_text():
+    return jsonify({'text': translate(request.form['text'],
+                                      request.form['source_language'],
+                                      request.form['dest_language'])})
+
+
+@bp.route('/search')
+@login_required
+def search():
+    if not g.search_form.validate():
+        return redirect(url_for('main.explore'))
+    page = request.args.get('page', 1, type=int)
+    posts, total = Post.search(g.search_form.q.data, page,
+                               current_app.config['POSTS_PER_PAGE'])
+    next_url = url_for('main.search', q=g.search_form.q.data, page=page + 1) \
+        if total > page * current_app.config['POSTS_PER_PAGE'] else None
+    prev_url = url_for('main.search', q=g.search_form.q.data, page=page - 1) \
+        if page > 1 else None
+    return render_template('search.html', title=_('Search'), posts=posts,
+                           next_url=next_url, prev_url=prev_url)
+
+
+@bp.route('/send_message/<recipient>', methods=['GET', 'POST'])
+@login_required
+def send_message(recipient):
+    user = User.query.filter_by(username=recipient).first_or_404()
+    form = MessageForm()
+    if form.validate_on_submit():
+        msg = Message(author=current_user, recipient=user,
+                      body=form.message.data)
+        db.session.add(msg)
+        user.add_notification('unread_message_count', user.new_messages())
+        db.session.commit()
+        flash(_('Your message has been sent.'))
+        return redirect(url_for('main.user', username=recipient))
+    return render_template('send_message.html', title=_('Send Message'),
+                           form=form, recipient=recipient)
+
+
+@bp.route('/messages')
+@login_required
+def messages():
+    current_user.last_message_read_time = datetime.utcnow()
+    current_user.add_notification('unread_message_count', 0)
+    db.session.commit()
+    page = request.args.get('page', 1, type=int)
+    messages = current_user.messages_received.order_by(
+        Message.timestamp.desc()).paginate(
+            page=page, per_page=current_app.config['POSTS_PER_PAGE'],
+            error_out=False)
+    next_url = url_for('main.messages', page=messages.next_num) \
+        if messages.has_next else None
+    prev_url = url_for('main.messages', page=messages.prev_num) \
+        if messages.has_prev else None
+    return render_template('messages.html', messages=messages.items,
+                           next_url=next_url, prev_url=prev_url)
+
+
+@bp.route('/export_posts')
+@login_required
+def export_posts():
+    if current_user.get_task_in_progress('export_posts'):
+        flash(_('An export task is currently in progress'))
+    else:
+        current_user.launch_task('export_posts', _('Exporting posts...'))
+        db.session.commit()
+    return redirect(url_for('main.user', username=current_user.username))
+
+
+@bp.route('/notifications')
+@login_required
+def notifications():
+    since = request.args.get('since', 0.0, type=float)
+    notifications = current_user.notifications.filter(
+        Notification.timestamp > since).order_by(Notification.timestamp.asc())
+    return jsonify([{
+        'name': n.name,
+        'data': n.get_data(),
+        'timestamp': n.timestamp
+    } for n in notifications])

app/models.py

@@ -0,0 +1,293 @@
+import base64
+from datetime import datetime, timedelta
+from hashlib import md5
+import json
+import os
+from time import time
+from flask import current_app, url_for
+from flask_login import UserMixin
+from werkzeug.security import generate_password_hash, check_password_hash
+import jwt
+import redis
+import rq
+from app import db, login
+from app.search import add_to_index, remove_from_index, query_index
+
+
+class SearchableMixin(object):
+    @classmethod
+    def search(cls, expression, page, per_page):
+        ids, total = query_index(cls.__tablename__, expression, page, per_page)
+        if total == 0:
+            return cls.query.filter_by(id=0), 0
+        when = []
+        for i in range(len(ids)):
+            when.append((ids[i], i))
+        return cls.query.filter(cls.id.in_(ids)).order_by(
+            db.case(when, value=cls.id)), total
+
+    @classmethod
+    def before_commit(cls, session):
+        session._changes = {
+            'add': list(session.new),
+            'update': list(session.dirty),
+            'delete': list(session.deleted)
+        }
+
+    @classmethod
+    def after_commit(cls, session):
+        for obj in session._changes['add']:
+            if isinstance(obj, SearchableMixin):
+                add_to_index(obj.__tablename__, obj)
+        for obj in session._changes['update']:
+            if isinstance(obj, SearchableMixin):
+                add_to_index(obj.__tablename__, obj)
+        for obj in session._changes['delete']:
+            if isinstance(obj, SearchableMixin):
+                remove_from_index(obj.__tablename__, obj)
+        session._changes = None
+
+    @classmethod
+    def reindex(cls):
+        for obj in cls.query:
+            add_to_index(cls.__tablename__, obj)
+
+
+db.event.listen(db.session, 'before_commit', SearchableMixin.before_commit)
+db.event.listen(db.session, 'after_commit', SearchableMixin.after_commit)
+
+
+class PaginatedAPIMixin(object):
+    @staticmethod
+    def to_collection_dict(query, page, per_page, endpoint, **kwargs):
+        resources = query.paginate(page=page, per_page=per_page,
+                                   error_out=False)
+        data = {
+            'items': [item.to_dict() for item in resources.items],
+            '_meta': {
+                'page': page,
+                'per_page': per_page,
+                'total_pages': resources.pages,
+                'total_items': resources.total
+            },
+            '_links': {
+                'self': url_for(endpoint, page=page, per_page=per_page,
+                                **kwargs),
+                'next': url_for(endpoint, page=page + 1, per_page=per_page,
+                                **kwargs) if resources.has_next else None,
+                'prev': url_for(endpoint, page=page - 1, per_page=per_page,
+                                **kwargs) if resources.has_prev else None
+            }
+        }
+        return data
+
+
+followers = db.Table(
+    'followers',
+    db.Column('follower_id', db.Integer, db.ForeignKey('user.id')),
+    db.Column('followed_id', db.Integer, db.ForeignKey('user.id'))
+)
+
+
+class User(UserMixin, PaginatedAPIMixin, db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    username = db.Column(db.String(64), index=True, unique=True)
+    email = db.Column(db.String(120), index=True, unique=True)
+    password_hash = db.Column(db.String(128))
+    posts = db.relationship('Post', backref='author', lazy='dynamic')
+    about_me = db.Column(db.String(140))
+    last_seen = db.Column(db.DateTime, default=datetime.utcnow)
+    token = db.Column(db.String(32), index=True, unique=True)
+    token_expiration = db.Column(db.DateTime)
+    followed = db.relationship(
+        'User', secondary=followers,
+        primaryjoin=(followers.c.follower_id == id),
+        secondaryjoin=(followers.c.followed_id == id),
+        backref=db.backref('followers', lazy='dynamic'), lazy='dynamic')
+    messages_sent = db.relationship('Message',
+                                    foreign_keys='Message.sender_id',
+                                    backref='author', lazy='dynamic')
+    messages_received = db.relationship('Message',
+                                        foreign_keys='Message.recipient_id',
+                                        backref='recipient', lazy='dynamic')
+    last_message_read_time = db.Column(db.DateTime)
+    notifications = db.relationship('Notification', backref='user',
+                                    lazy='dynamic')
+    tasks = db.relationship('Task', backref='user', lazy='dynamic')
+
+    def __repr__(self):
+        return '<User {}>'.format(self.username)
+
+    def set_password(self, password):
+        self.password_hash = generate_password_hash(password)
+
+    def check_password(self, password):
+        return check_password_hash(self.password_hash, password)
+
+    def avatar(self, size):
+        digest = md5(self.email.lower().encode('utf-8')).hexdigest()
+        return 'https://www.gravatar.com/avatar/{}?d=identicon&s={}'.format(
+            digest, size)
+
+    def follow(self, user):
+        if not self.is_following(user):
+            self.followed.append(user)
+
+    def unfollow(self, user):
+        if self.is_following(user):
+            self.followed.remove(user)
+
+    def is_following(self, user):
+        return self.followed.filter(
+            followers.c.followed_id == user.id).count() > 0
+
+    def followed_posts(self):
+        followed = Post.query.join(
+            followers, (followers.c.followed_id == Post.user_id)).filter(
+                followers.c.follower_id == self.id)
+        own = Post.query.filter_by(user_id=self.id)
+        return followed.union(own).order_by(Post.timestamp.desc())
+
+    def get_reset_password_token(self, expires_in=600):
+        return jwt.encode(
+            {'reset_password': self.id, 'exp': time() + expires_in},
+            current_app.config['SECRET_KEY'], algorithm='HS256')
+
+    @staticmethod
+    def verify_reset_password_token(token):
+        try:
+            id = jwt.decode(token, current_app.config['SECRET_KEY'],
+                            algorithms=['HS256'])['reset_password']
+        except:
+            return
+        return User.query.get(id)
+
+    def new_messages(self):
+        last_read_time = self.last_message_read_time or datetime(1900, 1, 1)
+        return Message.query.filter_by(recipient=self).filter(
+            Message.timestamp > last_read_time).count()
+
+    def add_notification(self, name, data):
+        self.notifications.filter_by(name=name).delete()
+        n = Notification(name=name, payload_json=json.dumps(data), user=self)
+        db.session.add(n)
+        return n
+
+    def launch_task(self, name, description, *args, **kwargs):
+        rq_job = current_app.task_queue.enqueue('app.tasks.' + name, self.id,
+                                                *args, **kwargs)
+        task = Task(id=rq_job.get_id(), name=name, description=description,
+                    user=self)
+        db.session.add(task)
+        return task
+
+    def get_tasks_in_progress(self):
+        return Task.query.filter_by(user=self, complete=False).all()
+
+    def get_task_in_progress(self, name):
+        return Task.query.filter_by(name=name, user=self,
+                                    complete=False).first()
+
+    def to_dict(self, include_email=False):
+        data = {
+            'id': self.id,
+            'username': self.username,
+            'last_seen': self.last_seen.isoformat() + 'Z',
+            'about_me': self.about_me,
+            'post_count': self.posts.count(),
+            'follower_count': self.followers.count(),
+            'followed_count': self.followed.count(),
+            '_links': {
+                'self': url_for('api.get_user', id=self.id),
+                'followers': url_for('api.get_followers', id=self.id),
+                'followed': url_for('api.get_followed', id=self.id),
+                'avatar': self.avatar(128)
+            }
+        }
+        if include_email:
+            data['email'] = self.email
+        return data
+
+    def from_dict(self, data, new_user=False):
+        for field in ['username', 'email', 'about_me']:
+            if field in data:
+                setattr(self, field, data[field])
+        if new_user and 'password' in data:
+            self.set_password(data['password'])
+
+    def get_token(self, expires_in=3600):
+        now = datetime.utcnow()
+        if self.token and self.token_expiration > now + timedelta(seconds=60):
+            return self.token
+        self.token = base64.b64encode(os.urandom(24)).decode('utf-8')
+        self.token_expiration = now + timedelta(seconds=expires_in)
+        db.session.add(self)
+        return self.token
+
+    def revoke_token(self):
+        self.token_expiration = datetime.utcnow() - timedelta(seconds=1)
+
+    @staticmethod
+    def check_token(token):
+        user = User.query.filter_by(token=token).first()
+        if user is None or user.token_expiration < datetime.utcnow():
+            return None
+        return user
+
+
+@login.user_loader
+def load_user(id):
+    return User.query.get(int(id))
+
+
+class Post(SearchableMixin, db.Model):
+    __searchable__ = ['body']
+    id = db.Column(db.Integer, primary_key=True)
+    body = db.Column(db.String(140))
+    timestamp = db.Column(db.DateTime, index=True, default=datetime.utcnow)
+    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
+    language = db.Column(db.String(5))
+
+    def __repr__(self):
+        return '<Post {}>'.format(self.body)
+
+
+class Message(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    sender_id = db.Column(db.Integer, db.ForeignKey('user.id'))
+    recipient_id = db.Column(db.Integer, db.ForeignKey('user.id'))
+    body = db.Column(db.String(140))
+    timestamp = db.Column(db.DateTime, index=True, default=datetime.utcnow)
+
+    def __repr__(self):
+        return '<Message {}>'.format(self.body)
+
+
+class Notification(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(128), index=True)
+    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
+    timestamp = db.Column(db.Float, index=True, default=time)
+    payload_json = db.Column(db.Text)
+
+    def get_data(self):
+        return json.loads(str(self.payload_json))
+
+
+class Task(db.Model):
+    id = db.Column(db.String(36), primary_key=True)
+    name = db.Column(db.String(128), index=True)
+    description = db.Column(db.String(128))
+    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
+    complete = db.Column(db.Boolean, default=False)
+
+    def get_rq_job(self):
+        try:
+            rq_job = rq.job.Job.fetch(self.id, connection=current_app.redis)
+        except (redis.exceptions.RedisError, rq.exceptions.NoSuchJobError):
+            return None
+        return rq_job
+
+    def get_progress(self):
+        job = self.get_rq_job()
+        return job.meta.get('progress', 0) if job is not None else 100

app/routes.py

@@ -1,30 +0,0 @@
-from flask import render_template, flash, redirect, url_for
-from app import app
-from app.forms import LoginForm
-
-
-@app.route('/')
-@app.route('/index')
-def index():
-    user = {'username': 'Miguel'}
-    posts = [
-        {
-            'author': {'username': 'John'},
-            'body': 'Beautiful day in Portland!'
-        },
-        {
-            'author': {'username': 'Susan'},
-            'body': 'The Avengers movie was so cool!'
-        }
-    ]
-    return render_template('index.html', title='Home', user=user, posts=posts)
-
-
-@app.route('/login', methods=['GET', 'POST'])
-def login():
-    form = LoginForm()
-    if form.validate_on_submit():
-        flash('Login requested for user {}, remember_me={}'.format(
-            form.username.data, form.remember_me.data))
-        return redirect(url_for('index'))
-    return render_template('login.html',  title='Sign In', form=form)

app/search.py

@@ -0,0 +1,27 @@
+from flask import current_app
+
+
+def add_to_index(index, model):
+    if not current_app.elasticsearch:
+        return
+    payload = {}
+    for field in model.__searchable__:
+        payload[field] = getattr(model, field)
+    current_app.elasticsearch.index(index=index, id=model.id, body=payload)
+
+
+def remove_from_index(index, model):
+    if not current_app.elasticsearch:
+        return
+    current_app.elasticsearch.delete(index=index, id=model.id)
+
+
+def query_index(index, query, page, per_page):
+    if not current_app.elasticsearch:
+        return [], 0
+    search = current_app.elasticsearch.search(
+        index=index,
+        body={'query': {'multi_match': {'query': query, 'fields': ['*']}},
+              'from': (page - 1) * per_page, 'size': per_page})
+    ids = [int(hit['_id']) for hit in search['hits']['hits']]
+    return ids, search['hits']['total']['value']

app/tasks.py

@@ -0,0 +1,51 @@
+import json
+import sys
+import time
+from flask import render_template
+from rq import get_current_job
+from app import create_app, db
+from app.models import User, Post, Task
+from app.email import send_email
+
+app = create_app()
+app.app_context().push()
+
+
+def _set_task_progress(progress):
+    job = get_current_job()
+    if job:
+        job.meta['progress'] = progress
+        job.save_meta()
+        task = Task.query.get(job.get_id())
+        task.user.add_notification('task_progress', {'task_id': job.get_id(),
+                                                     'progress': progress})
+        if progress >= 100:
+            task.complete = True
+        db.session.commit()
+
+
+def export_posts(user_id):
+    try:
+        user = User.query.get(user_id)
+        _set_task_progress(0)
+        data = []
+        i = 0
+        total_posts = user.posts.count()
+        for post in user.posts.order_by(Post.timestamp.asc()):
+            data.append({'body': post.body,
+                         'timestamp': post.timestamp.isoformat() + 'Z'})
+            time.sleep(5)
+            i += 1
+            _set_task_progress(100 * i // total_posts)
+
+        send_email('[Microblog] Your blog posts',
+                sender=app.config['ADMINS'][0], recipients=[user.email],
+                text_body=render_template('email/export_posts.txt', user=user),
+                html_body=render_template('email/export_posts.html',
+                                          user=user),
+                attachments=[('posts.json', 'application/json',
+                              json.dumps({'posts': data}, indent=4))],
+                sync=True)
+    except:
+        _set_task_progress(100)
+        app.logger.error('Unhandled exception', exc_info=sys.exc_info())

app/templates/_post.html

@@ -0,0 +1,32 @@
+    <table class="table table-hover">
+        <tr>
+            <td width="70px">
+                <a href="{{ url_for('main.user', username=post.author.username) }}">
+                    <img src="{{ post.author.avatar(70) }}" />
+                </a>
+            </td>
+            <td>
+                {% set user_link %}
+                    <span class="user_popup">
+                        <a href="{{ url_for('main.user', username=post.author.username) }}">
+                            {{ post.author.username }}
+                        </a>
+                    </span>
+                {% endset %}
+                {{ _('%(username)s said %(when)s',
+                    username=user_link, when=moment(post.timestamp).fromNow()) }}
+                <br>
+                <span id="post{{ post.id }}">{{ post.body }}</span>
+                {% if post.language and post.language != g.locale %}
+                <br><br>
+                <span id="translation{{ post.id }}">
+                    <a href="javascript:translate(
+                                '#post{{ post.id }}',
+                                '#translation{{ post.id }}',
+                                '{{ post.language }}',
+                                '{{ g.locale }}');">{{ _('Translate') }}</a>
+                </span>
+                {% endif %}
+            </td>
+        </tr>
+    </table>

app/templates/auth/login.html

@@ -0,0 +1,17 @@
+{% extends 'base.html' %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Sign In') }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+    <br>
+    <p>{{ _('New User?') }} <a href="{{ url_for('auth.register') }}">{{ _('Click to Register!') }}</a></p>
+    <p>
+        {{ _('Forgot Your Password?') }}
+        <a href="{{ url_for('auth.reset_password_request') }}">{{ _('Click to Reset It') }}</a>
+    </p>
+{% endblock %}

app/templates/auth/register.html

@@ -0,0 +1,11 @@
+{% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Register') }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+{% endblock %}

app/templates/auth/reset_password.html

@@ -0,0 +1,11 @@
+{% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Reset Your Password') }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+{% endblock %}

app/templates/auth/reset_password_request.html

@@ -0,0 +1,11 @@
+{% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Reset Password') }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+{% endblock %}

app/templates/base.html

@@ -1,28 +1,171 @@
-<!doctype html>
-<html>
-    <head>
-        {% if title %}
-        <title>{{ title }} - Microblog</title>
-        {% else %}
-        <title>Welcome to Microblog</title>
-        {% endif %}
-    </head>
-    <body>
-        <div>
-            Microblog:
-            <a href="{{ url_for('index') }}">Home</a>
-            <a href="{{ url_for('login') }}">Login</a>
+{% extends 'bootstrap/base.html' %}
+
+{% block title %}
+    {% if title %}{{ title }} - Microblog{% else %}{{ _('Welcome to Microblog') }}{% endif %}
+{% endblock %}
+
+{% block navbar %}
+    <nav class="navbar navbar-default">
+        <div class="container">
+            <div class="navbar-header">
+                <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
+                    <span class="sr-only">Toggle navigation</span>
+                    <span class="icon-bar"></span>
+                    <span class="icon-bar"></span>
+                    <span class="icon-bar"></span>
+                </button>
+                <a class="navbar-brand" href="{{ url_for('main.index') }}">Microblog</a>
             </div>
-        <hr>
-        {% with messages = get_flashed_messages() %}
-        {% if messages %}
-        <ul>
-            {% for message in messages %}
-            <li>{{ message }}</li>
-            {% endfor %}
+            <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
+                <ul class="nav navbar-nav">
+                    <li><a href="{{ url_for('main.index') }}">{{ _('Home') }}</a></li>
+                    <li><a href="{{ url_for('main.explore') }}">{{ _('Explore') }}</a></li>
                 </ul>
+                {% if g.search_form %}
+                <form class="navbar-form navbar-left" method="get" action="{{ url_for('main.search') }}">
+                    <div class="form-group">
+                        {{ g.search_form.q(size=20, class='form-control', placeholder=g.search_form.q.label.text) }}
+                    </div>
+                </form>
+                {% endif %}
+                <ul class="nav navbar-nav navbar-right">
+                    {% if current_user.is_anonymous %}
+                    <li><a href="{{ url_for('auth.login') }}">{{ _('Login') }}</a></li>
+                    {% else %}
+                    <li>
+                        <a href="{{ url_for('main.messages') }}">{{ _('Messages') }}
+                            {% set new_messages = current_user.new_messages() %}
+                            <span id="message_count" class="badge"
+                                  style="visibility: {% if new_messages %}visible
+                                                     {% else %}hidden{% endif %};">
+                                {{ new_messages }}
+                            </span>
+                        </a>
+                    </li>
+                    <li><a href="{{ url_for('main.user', username=current_user.username) }}">{{ _('Profile') }}</a></li>
+                    <li><a href="{{ url_for('auth.logout') }}">{{ _('Logout') }}</a></li>
+                    {% endif %}
+                </ul>
+            </div>
+        </div>
+    </nav>
+{% endblock %}
+
+{% block content %}
+    <div class="container">
+        {% if current_user.is_authenticated %}
+        {% with tasks = current_user.get_tasks_in_progress() %}
+        {% if tasks %}
+            {% for task in tasks %}
+            <div class="alert alert-success" role="alert">
+                {{ task.description }}
+                <span id="{{ task.id }}-progress">{{ task.get_progress() }}</span>%
+            </div>
+            {% endfor %}
         {% endif %}
         {% endwith %}
-        {% block content %}{% endblock %}
-    </body>
-</html>
+        {% endif %}
+        {% with messages = get_flashed_messages() %}
+        {% if messages %}
+            {% for message in messages %}
+            <div class="alert alert-info" role="alert">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+        {% endwith %}
+
+        {# application content needs to be provided in the app_content block #}
+        {% block app_content %}{% endblock %}
+    </div>
+{% endblock %}
+
+{% block scripts %}
+    {{ super() }}
+    {{ moment.include_moment() }}
+    {{ moment.lang(g.locale) }}
+    <script>
+        function translate(sourceElem, destElem, sourceLang, destLang) {
+            $(destElem).html('<img src="{{ url_for('static', filename='loading.gif') }}">');
+            $.post('/translate', {
+                text: $(sourceElem).text(),
+                source_language: sourceLang,
+                dest_language: destLang
+            }).done(function(response) {
+                $(destElem).text(response['text'])
+            }).fail(function() {
+                $(destElem).text("{{ _('Error: Could not contact server.') }}");
+            });
+        }
+        $(function () {
+            var timer = null;
+            var xhr = null;
+            $('.user_popup').hover(
+                function(event) {
+                    // mouse in event handler
+                    var elem = $(event.currentTarget);
+                    timer = setTimeout(function() {
+                        timer = null;
+                        xhr = $.ajax(
+                            '/user/' + elem.first().text().trim() + '/popup').done(
+                                function(data) {
+                                    xhr = null;
+                                    elem.popover({
+                                        trigger: 'manual',
+                                        html: true,
+                                        animation: false,
+                                        container: elem,
+                                        content: data
+                                    }).popover('show');
+                                    flask_moment_render_all();
+                                }
+                            );
+                    }, 1000);
+                },
+                function(event) {
+                    // mouse out event handler
+                    var elem = $(event.currentTarget);
+                    if (timer) {
+                        clearTimeout(timer);
+                        timer = null;
+                    }
+                    else if (xhr) {
+                        xhr.abort();
+                        xhr = null;
+                    }
+                    else {
+                        elem.popover('destroy');
+                    }
+                }
+            );
+        });
+        function set_message_count(n) {
+            $('#message_count').text(n);
+            $('#message_count').css('visibility', n ? 'visible' : 'hidden');
+        }
+        function set_task_progress(task_id, progress) {
+            $('#' + task_id + '-progress').text(progress);
+        }
+        {% if current_user.is_authenticated %}
+        $(function() {
+            var since = 0;
+            setInterval(function() {
+                $.ajax('{{ url_for('main.notifications') }}?since=' + since).done(
+                    function(notifications) {
+                        for (var i = 0; i < notifications.length; i++) {
+                            switch (notifications[i].name) {
+                                case 'unread_message_count':
+                                    set_message_count(notifications[i].data);
+                                    break;
+                                case 'task_progress':
+                                    set_task_progress(notifications[i].data.task_id,
+                                        notifications[i].data.progress);
+                                    break;
+                            }
+                            since = notifications[i].timestamp;
+                        }
+                    }
+                );
+            }, 10000);
+        });
+        {% endif %}
+    </script>
+{% endblock %}

app/templates/edit_profile.html

@@ -0,0 +1,11 @@
+{% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Edit Profile') }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+{% endblock %}

app/templates/email/export_posts.html

@@ -0,0 +1,4 @@
+<p>Dear {{ user.username }},</p>
+<p>Please find attached the archive of your posts that you requested.</p>
+<p>Sincerely,</p>
+<p>The Microblog Team</p>

app/templates/email/export_posts.txt

@@ -0,0 +1,7 @@
+Dear {{ user.username }},
+
+Please find attached the archive of your posts that you requested.
+
+Sincerely,
+
+The Microblog Team

app/templates/email/reset_password.html

@@ -0,0 +1,12 @@
+<p>Dear {{ user.username }},</p>
+<p>
+    To reset your password
+    <a href="{{ url_for('auth.reset_password', token=token, _external=True) }}">
+        click here
+    </a>.
+</p>
+<p>Alternatively, you can paste the following link in your browser's address bar:</p>
+<p>{{ url_for('auth.reset_password', token=token, _external=True) }}</p>
+<p>If you have not requested a password reset simply ignore this message.</p>
+<p>Sincerely,</p>
+<p>The Microblog Team</p>

app/templates/email/reset_password.txt

@@ -0,0 +1,11 @@
+Dear {{ user.username }},
+
+To reset your password click on the following link:
+
+{{ url_for('auth.reset_password', token=token, _external=True) }}
+
+If you have not requested a password reset simply ignore this message.
+
+Sincerely,
+
+The Microblog Team

app/templates/errors/404.html

@@ -0,0 +1,6 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <h1>{{ _('Not Found') }}</h1>
+    <p><a href="{{ url_for('main.index') }}">{{ _('Back') }}</a></p>
+{% endblock %}

app/templates/errors/500.html

@@ -0,0 +1,7 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <h1>{{ _('An unexpected error has occurred') }}</h1>
+    <p>{{ _('The administrator has been notified. Sorry for the inconvenience!') }}</p>
+    <p><a href="{{ url_for('main.index') }}">{{ _('Back') }}</a></p>
+{% endblock %}

app/templates/index.html

@@ -1,8 +1,27 @@
 {% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
 
-{% block content %}
-    <h1>Hi, {{ user.username }}!</h1>
+{% block app_content %}
+    <h1>{{ _('Hi, %(username)s!', username=current_user.username) }}</h1>
+    {% if form %}
+    {{ wtf.quick_form(form) }}
+    <br>
+    {% endif %}
     {% for post in posts %}
-    <div><p>{{ post.author.username }} says: <b>{{ post.body }}</b></p></div>
+        {% include '_post.html' %}
     {% endfor %}
+    <nav aria-label="...">
+        <ul class="pager">
+            <li class="previous{% if not prev_url %} disabled{% endif %}">
+                <a href="{{ prev_url or '#' }}">
+                    <span aria-hidden="true">&larr;</span> {{ _('Newer posts') }}
+                </a>
+            </li>
+            <li class="next{% if not next_url %} disabled{% endif %}">
+                <a href="{{ next_url or '#' }}">
+                    {{ _('Older posts') }} <span aria-hidden="true">&rarr;</span>
+                </a>
+            </li>
+        </ul>
+    </nav>
 {% endblock %}

app/templates/login.html

@@ -1,24 +0,0 @@
-{% extends "base.html" %}
-
-{% block content %}
-    <h1>Sign In</h1>
-    <form action="" method="post" novalidate>
-        {{ form.hidden_tag() }}
-        <p>
-            {{ form.username.label }}<br>
-            {{ form.username(size=32) }}<br>
-            {% for error in form.username.errors %}
-            <span style="color: red;">[{{ error }}]</span>
-            {% endfor %}
-        </p>
-        <p>
-            {{ form.password.label }}<br>
-            {{ form.password(size=32) }}<br>
-            {% for error in form.password.errors %}
-            <span style="color: red;">[{{ error }}]</span>
-            {% endfor %}
-        </p>
-        <p>{{ form.remember_me() }} {{ form.remember_me.label }}</p>
-        <p>{{ form.submit() }}</p>
-    </form>
-{% endblock %}

app/templates/messages.html

@@ -0,0 +1,22 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <h1>{{ _('Messages') }}</h1>
+    {% for post in messages %}
+        {% include '_post.html' %}
+    {% endfor %}
+    <nav aria-label="...">
+        <ul class="pager">
+            <li class="previous{% if not prev_url %} disabled{% endif %}">
+                <a href="{{ prev_url or '#' }}">
+                    <span aria-hidden="true">&larr;</span> {{ _('Newer messages') }}
+                </a>
+            </li>
+            <li class="next{% if not next_url %} disabled{% endif %}">
+                <a href="{{ next_url or '#' }}">
+                    {{ _('Older messages') }} <span aria-hidden="true">&rarr;</span>
+                </a>
+            </li>
+        </ul>
+    </nav>
+{% endblock %}

app/templates/search.html

@@ -0,0 +1,22 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <h1>{{ _('Search Results') }}</h1>
+    {% for post in posts %}
+        {% include '_post.html' %}
+    {% endfor %}
+    <nav aria-label="...">
+        <ul class="pager">
+            <li class="previous{% if not prev_url %} disabled{% endif %}">
+                <a href="{{ prev_url or '#' }}">
+                    <span aria-hidden="true">&larr;</span> {{ _('Previous results') }}
+                </a>
+            </li>
+            <li class="next{% if not next_url %} disabled{% endif %}">
+                <a href="{{ next_url or '#' }}">
+                    {{ _('Next results') }} <span aria-hidden="true">&rarr;</span>
+                </a>
+            </li>
+        </ul>
+    </nav>
+{% endblock %}

app/templates/send_message.html

@@ -0,0 +1,11 @@
+{% extends "base.html" %}
+{% import 'bootstrap/wtf.html' as wtf %}
+
+{% block app_content %}
+    <h1>{{ _('Send Message to %(recipient)s', recipient=recipient) }}</h1>
+    <div class="row">
+        <div class="col-md-4">
+            {{ wtf.quick_form(form) }}
+        </div>
+    </div>
+{% endblock %}

app/templates/user.html

@@ -0,0 +1,57 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <table class="table table-hover">
+        <tr>
+            <td width="256px"><img src="{{ user.avatar(256) }}"></td>
+            <td>
+                <h1>{{ _('User') }}: {{ user.username }}</h1>
+                {% if user.about_me %}<p>{{ user.about_me }}</p>{% endif %}
+                {% if user.last_seen %}
+                <p>{{ _('Last seen on') }}: {{ moment(user.last_seen).format('LLL') }}</p>
+                {% endif %}
+                <p>{{ _('%(count)d followers', count=user.followers.count()) }}, {{ _('%(count)d following', count=user.followed.count()) }}</p>
+                {% if user == current_user %}
+                <p><a href="{{ url_for('main.edit_profile') }}">{{ _('Edit your profile') }}</a></p>
+                {% if not current_user.get_task_in_progress('export_posts') %}
+                <p><a href="{{ url_for('main.export_posts') }}">{{ _('Export your posts') }}</a></p>
+                {% endif %}
+                {% elif not current_user.is_following(user) %}
+                <p>
+                    <form action="{{ url_for('main.follow', username=user.username) }}" method="post">
+                        {{ form.hidden_tag() }}
+                        {{ form.submit(value=_('Follow'), class_='btn btn-default') }}
+                    </form>
+                </p>
+                {% else %}
+                <p>
+                    <form action="{{ url_for('main.unfollow', username=user.username) }}" method="post">
+                        {{ form.hidden_tag() }}
+                        {{ form.submit(value=_('Unfollow'), class_='btn btn-default') }}
+                    </form>
+                </p>
+                {% endif %}
+                {% if user != current_user %}
+                <p><a href="{{ url_for('main.send_message', recipient=user.username) }}">{{ _('Send private message') }}</a></p>
+                {% endif %}
+            </td>
+        </tr>
+    </table>
+    {% for post in posts %}
+        {% include '_post.html' %}
+    {% endfor %}
+    <nav aria-label="...">
+        <ul class="pager">
+            <li class="previous{% if not prev_url %} disabled{% endif %}">
+                <a href="{{ prev_url or '#' }}">
+                    <span aria-hidden="true">&larr;</span> {{ _('Newer posts') }}
+                </a>
+            </li>
+            <li class="next{% if not next_url %} disabled{% endif %}">
+                <a href="{{ next_url or '#' }}">
+                    {{ _('Older posts') }} <span aria-hidden="true">&rarr;</span>
+                </a>
+            </li>
+        </ul>
+    </nav>
+{% endblock %}

app/templates/user_popup.html

@@ -0,0 +1,32 @@
+<table class="table">
+    <tr>
+        <td width="64" style="border: 0px;"><img src="{{ user.avatar(64) }}"></td>
+        <td style="border: 0px;">
+            <p><a href="{{ url_for('main.user', username=user.username) }}">{{ user.username }}</a></p>
+            <small>
+                {% if user.about_me %}<p>{{ user.about_me }}</p>{% endif %}
+                {% if user.last_seen %}
+                <p>{{ _('Last seen on') }}: {{ moment(user.last_seen).format('lll') }}</p>
+                {% endif %}
+                <p>{{ _('%(count)d followers', count=user.followers.count()) }}, {{ _('%(count)d following', count=user.followed.count()) }}</p>
+                {% if user != current_user %}
+                    {% if not current_user.is_following(user) %}
+                    <p>
+                        <form action="{{ url_for('main.follow', username=user.username) }}" method="post">
+                            {{ form.hidden_tag() }}
+                            {{ form.submit(value=_('Follow'), class_='btn btn-default btn-sm') }}
+                        </form>
+                    </p>
+                    {% else %}
+                    <p>
+                        <form action="{{ url_for('main.unfollow', username=user.username) }}" method="post">
+                            {{ form.hidden_tag() }}
+                            {{ form.submit(value=_('Unfollow'), class_='btn btn-default btm-sm') }}
+                        </form>
+                    </p>
+                    {% endif %}
+                {% endif %}
+            </small>
+        </td>
+    </tr>
+</table>

app/translate.py

@@ -0,0 +1,21 @@
+import json
+import requests
+from flask import current_app
+from flask_babel import _
+
+
+def translate(text, source_language, dest_language):
+    if 'MS_TRANSLATOR_KEY' not in current_app.config or \
+            not current_app.config['MS_TRANSLATOR_KEY']:
+        return _('Error: the translation service is not configured.')
+    auth = {
+        'Ocp-Apim-Subscription-Key': current_app.config['MS_TRANSLATOR_KEY'],
+        'Ocp-Apim-Subscription-Region': 'westus2'}
+    r = requests.post(
+        'https://api.cognitive.microsofttranslator.com'
+        '/translate?api-version=3.0&from={}&to={}'.format(
+            source_language, dest_language), headers=auth, json=[
+                {'Text': text}])
+    if r.status_code != 200:
+        return _('Error: the translation service failed.')
+    return r.json()[0]['translations'][0]['text']

app/translations/es/LC_MESSAGES/messages.po

@@ -0,0 +1,320 @@
+# Spanish translations for PROJECT.
+# Copyright (C) 2017 ORGANIZATION
+# This file is distributed under the same license as the PROJECT project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2017.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: PROJECT VERSION\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2017-11-25 18:27-0800\n"
+"PO-Revision-Date: 2017-09-29 23:25-0700\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language: es\n"
+"Language-Team: es <LL@li.org>\n"
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 2.5.1\n"
+
+#: app/__init__.py:20
+msgid "Please log in to access this page."
+msgstr "Por favor ingrese para acceder a esta página."
+
+#: app/translate.py:10
+msgid "Error: the translation service is not configured."
+msgstr "Error: el servicio de traducciones no está configurado."
+
+#: app/translate.py:18
+msgid "Error: the translation service failed."
+msgstr "Error el servicio de traducciones ha fallado."
+
+#: app/auth/email.py:8
+msgid "[Microblog] Reset Your Password"
+msgstr "[Microblog] Nueva Contraseña"
+
+#: app/auth/forms.py:10 app/auth/forms.py:17 app/main/forms.py:10
+msgid "Username"
+msgstr "Nombre de usuario"
+
+#: app/auth/forms.py:11 app/auth/forms.py:19 app/auth/forms.py:42
+msgid "Password"
+msgstr "Contraseña"
+
+#: app/auth/forms.py:12
+msgid "Remember Me"
+msgstr "Recordarme"
+
+#: app/auth/forms.py:13 app/templates/auth/login.html:5
+msgid "Sign In"
+msgstr "Ingresar"
+
+#: app/auth/forms.py:18 app/auth/forms.py:37
+msgid "Email"
+msgstr "Email"
+
+#: app/auth/forms.py:21 app/auth/forms.py:44
+msgid "Repeat Password"
+msgstr "Repetir Contraseña"
+
+#: app/auth/forms.py:23 app/templates/auth/register.html:5
+msgid "Register"
+msgstr "Registrarse"
+
+#: app/auth/forms.py:28 app/main/forms.py:23
+msgid "Please use a different username."
+msgstr "Por favor use un nombre de usuario diferente."
+
+#: app/auth/forms.py:33
+msgid "Please use a different email address."
+msgstr "Por favor use una dirección de email diferente."
+
+#: app/auth/forms.py:38 app/auth/forms.py:46
+msgid "Request Password Reset"
+msgstr "Pedir una nueva contraseña"
+
+#: app/auth/routes.py:20
+msgid "Invalid username or password"
+msgstr "Nombre de usuario o contraseña inválidos"
+
+#: app/auth/routes.py:46
+msgid "Congratulations, you are now a registered user!"
+msgstr "¡Felicitaciones, ya eres un usuario registrado!"
+
+#: app/auth/routes.py:61
+msgid "Check your email for the instructions to reset your password"
+msgstr "Busca en tu email las instrucciones para crear una nueva contraseña"
+
+#: app/auth/routes.py:78
+msgid "Your password has been reset."
+msgstr "Tu contraseña ha sido cambiada."
+
+#: app/main/forms.py:11
+msgid "About me"
+msgstr "Acerca de mí"
+
+#: app/main/forms.py:13 app/main/forms.py:28 app/main/forms.py:44
+msgid "Submit"
+msgstr "Enviar"
+
+#: app/main/forms.py:27
+msgid "Say something"
+msgstr "Dí algo"
+
+#: app/main/forms.py:32
+msgid "Search"
+msgstr "Buscar"
+
+#: app/main/forms.py:43
+msgid "Message"
+msgstr "Mensaje"
+
+#: app/main/routes.py:36
+msgid "Your post is now live!"
+msgstr "¡Tu artículo ha sido publicado!"
+
+#: app/main/routes.py:94
+msgid "Your changes have been saved."
+msgstr "Tus cambios han sido salvados."
+
+#: app/main/routes.py:99 app/templates/edit_profile.html:5
+msgid "Edit Profile"
+msgstr "Editar Perfil"
+
+#: app/main/routes.py:108 app/main/routes.py:124
+#, python-format
+msgid "User %(username)s not found."
+msgstr "El usuario %(username)s no ha sido encontrado."
+
+#: app/main/routes.py:111
+msgid "You cannot follow yourself!"
+msgstr "¡No te puedes seguir a tí mismo!"
+
+#: app/main/routes.py:115
+#, python-format
+msgid "You are following %(username)s!"
+msgstr "¡Ahora estás siguiendo a %(username)s!"
+
+#: app/main/routes.py:127
+msgid "You cannot unfollow yourself!"
+msgstr "¡No te puedes dejar de seguir a tí mismo!"
+
+#: app/main/routes.py:131
+#, python-format
+msgid "You are not following %(username)s."
+msgstr "No estás siguiendo a %(username)s."
+
+#: app/main/routes.py:170
+msgid "Your message has been sent."
+msgstr "Tu mensaje ha sido enviado."
+
+#: app/main/routes.py:172
+msgid "Send Message"
+msgstr "Enviar Mensaje"
+
+#: app/main/routes.py:197
+msgid "An export task is currently in progress"
+msgstr "Una tarea de exportación esta en progreso"
+
+#: app/main/routes.py:199
+msgid "Exporting posts..."
+msgstr "Exportando artículos..."
+
+#: app/templates/_post.html:16
+#, python-format
+msgid "%(username)s said %(when)s"
+msgstr "%(username)s dijo %(when)s"
+
+#: app/templates/_post.html:27
+msgid "Translate"
+msgstr "Traducir"
+
+#: app/templates/base.html:4
+msgid "Welcome to Microblog"
+msgstr "Bienvenido a Microblog"
+
+#: app/templates/base.html:21
+msgid "Home"
+msgstr "Inicio"
+
+#: app/templates/base.html:22
+msgid "Explore"
+msgstr "Explorar"
+
+#: app/templates/base.html:33
+msgid "Login"
+msgstr "Ingresar"
+
+#: app/templates/base.html:36 app/templates/messages.html:4
+msgid "Messages"
+msgstr "Mensajes"
+
+#: app/templates/base.html:45
+msgid "Profile"
+msgstr "Perfil"
+
+#: app/templates/base.html:46
+msgid "Logout"
+msgstr "Salir"
+
+#: app/templates/base.html:95
+msgid "Error: Could not contact server."
+msgstr "Error: el servidor no pudo ser contactado."
+
+#: app/templates/index.html:5
+#, python-format
+msgid "Hi, %(username)s!"
+msgstr "¡Hola, %(username)s!"
+
+#: app/templates/index.html:17 app/templates/user.html:37
+msgid "Newer posts"
+msgstr "Artículos siguientes"
+
+#: app/templates/index.html:22 app/templates/user.html:42
+msgid "Older posts"
+msgstr "Artículos previos"
+
+#: app/templates/messages.html:12
+msgid "Newer messages"
+msgstr "Mensajes siguientes"
+
+#: app/templates/messages.html:17
+msgid "Older messages"
+msgstr "Mensajes previos"
+
+#: app/templates/search.html:4
+msgid "Search Results"
+msgstr ""
+
+#: app/templates/search.html:12
+msgid "Previous results"
+msgstr ""
+
+#: app/templates/search.html:17
+msgid "Next results"
+msgstr ""
+
+#: app/templates/send_message.html:5
+#, python-format
+msgid "Send Message to %(recipient)s"
+msgstr "Enviar Mensaje a %(recipient)s"
+
+#: app/templates/user.html:8
+msgid "User"
+msgstr "Usuario"
+
+#: app/templates/user.html:11 app/templates/user_popup.html:9
+msgid "Last seen on"
+msgstr "Última visita"
+
+#: app/templates/user.html:13 app/templates/user_popup.html:11
+#, python-format
+msgid "%(count)d followers"
+msgstr "%(count)d seguidores"
+
+#: app/templates/user.html:13 app/templates/user_popup.html:11
+#, python-format
+msgid "%(count)d following"
+msgstr "siguiendo a %(count)d"
+
+#: app/templates/user.html:15
+msgid "Edit your profile"
+msgstr "Editar tu perfil"
+
+#: app/templates/user.html:17
+msgid "Export your posts"
+msgstr "Exportar tus artículos"
+
+#: app/templates/user.html:20 app/templates/user_popup.html:14
+msgid "Follow"
+msgstr "Seguir"
+
+#: app/templates/user.html:22 app/templates/user_popup.html:16
+msgid "Unfollow"
+msgstr "Dejar de seguir"
+
+#: app/templates/user.html:25
+msgid "Send private message"
+msgstr "Enviar mensaje privado"
+
+#: app/templates/auth/login.html:12
+msgid "New User?"
+msgstr "¿Usuario Nuevo?"
+
+#: app/templates/auth/login.html:12
+msgid "Click to Register!"
+msgstr "¡Haz click aquí para registrarte!"
+
+#: app/templates/auth/login.html:14
+msgid "Forgot Your Password?"
+msgstr "¿Te olvidaste tu contraseña?"
+
+#: app/templates/auth/login.html:15
+msgid "Click to Reset It"
+msgstr "Haz click aquí para pedir una nueva"
+
+#: app/templates/auth/reset_password.html:5
+msgid "Reset Your Password"
+msgstr "Nueva Contraseña"
+
+#: app/templates/auth/reset_password_request.html:5
+msgid "Reset Password"
+msgstr "Nueva Contraseña"
+
+#: app/templates/errors/404.html:4
+msgid "Not Found"
+msgstr "Página No Encontrada"
+
+#: app/templates/errors/404.html:5 app/templates/errors/500.html:6
+msgid "Back"
+msgstr "Atrás"
+
+#: app/templates/errors/500.html:4
+msgid "An unexpected error has occurred"
+msgstr "Ha ocurrido un error inesperado"
+
+#: app/templates/errors/500.html:5
+msgid "The administrator has been notified. Sorry for the inconvenience!"
+msgstr "El administrador ha sido notificado. ¡Lamentamos la inconveniencia!"
+

babel.cfg

@@ -0,0 +1,3 @@
+[python: app/**.py]
+[jinja2: app/templates/**.html]
+extensions=jinja2.ext.autoescape,jinja2.ext.with_

boot.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+# this script is used to boot a Docker container
+source venv/bin/activate
+while true; do
+    flask db upgrade
+    if [[ "$?" == "0" ]]; then
+        break
+    fi
+    echo Deploy command failed, retrying in 5 secs...
+    sleep 5
+done
+flask translate compile
+exec gunicorn -b :5000 --access-logfile - --error-logfile - microblog:app

config.py

@@ -1,4 +1,25 @@
 import os
+from dotenv import load_dotenv
+
+basedir = os.path.abspath(os.path.dirname(__file__))
+load_dotenv(os.path.join(basedir, '.env'))
+
 
 class Config(object):
     SECRET_KEY = os.environ.get('SECRET_KEY') or 'you-will-never-guess'
+    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', '').replace(
+        'postgres://', 'postgresql://') or \
+        'sqlite:///' + os.path.join(basedir, 'app.db')
+    SQLALCHEMY_TRACK_MODIFICATIONS = False
+    LOG_TO_STDOUT = os.environ.get('LOG_TO_STDOUT')
+    MAIL_SERVER = os.environ.get('MAIL_SERVER')
+    MAIL_PORT = int(os.environ.get('MAIL_PORT') or 25)
+    MAIL_USE_TLS = os.environ.get('MAIL_USE_TLS') is not None
+    MAIL_USERNAME = os.environ.get('MAIL_USERNAME')
+    MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD')
+    ADMINS = ['your-email@example.com']
+    LANGUAGES = ['en', 'es']
+    MS_TRANSLATOR_KEY = os.environ.get('MS_TRANSLATOR_KEY')
+    ELASTICSEARCH_URL = os.environ.get('ELASTICSEARCH_URL')
+    REDIS_URL = os.environ.get('REDIS_URL') or 'redis://'
+    POSTS_PER_PAGE = 25

deployment/nginx/microblog

@@ -0,0 +1,37 @@
+server {
+    # listen on port 80 (http)
+    listen 80;
+    server_name _;
+    location / {
+        # redirect any requests to the same URL but on https
+        return 301 https://$host$request_uri;
+    }
+}
+server {
+    # listen on port 443 (https)
+    listen 443 ssl;
+    server_name _;
+
+    # location of the self-signed SSL certificate
+    ssl_certificate /home/ubuntu/microblog/certs/cert.pem;
+    ssl_certificate_key /home/ubuntu/microblog/certs/key.pem;
+
+    # write access and error logs to /var/log
+    access_log /var/log/microblog_access.log;
+    error_log /var/log/microblog_error.log;
+
+    location / {
+        # forward application requests to the gunicorn server
+        proxy_pass http://localhost:8000;
+        proxy_redirect off;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    }
+
+    location /static {
+        # handle static files directly, without forwarding to the application
+        alias /home/ubuntu/microblog/app/static;
+        expires 30d;
+    }
+}

deployment/supervisor/microblog-tasks.conf

@@ -0,0 +1,9 @@
+[program:microblog-tasks]
+command=/home/ubuntu/microblog/venv/bin/rq worker microblog-tasks
+numprocs=1
+directory=/home/ubuntu/microblog
+user=ubuntu
+autostart=true
+autorestart=true
+stopasgroup=true
+killasgroup=true

deployment/supervisor/microblog.conf

@@ -0,0 +1,8 @@
+[program:microblog]
+command=/home/ubuntu/microblog/venv/bin/gunicorn -b localhost:8000 -w 4 microblog:app
+directory=/home/ubuntu/microblog
+user=ubuntu
+autostart=true
+autorestart=true
+stopasgroup=true
+killasgroup=true

microblog.py

@@ -1 +1,11 @@
-from app import app
+from app import create_app, db, cli
+from app.models import User, Post, Message, Notification, Task
+
+app = create_app()
+cli.register(app)
+
+
+@app.shell_context_processor
+def make_shell_context():
+    return {'db': db, 'User': User, 'Post': Post, 'Message': Message,
+            'Notification': Notification, 'Task': Task}

migrations/README

@@ -0,0 +1 @@
+Generic single-database configuration.

migrations/alembic.ini

@@ -0,0 +1,45 @@
+# A generic, single database configuration.
+
+[alembic]
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

migrations/env.py

@@ -0,0 +1,87 @@
+from __future__ import with_statement
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+from logging.config import fileConfig
+import logging
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+logger = logging.getLogger('alembic.env')
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+from flask import current_app
+config.set_main_option('sqlalchemy.url',
+                       current_app.config.get('SQLALCHEMY_DATABASE_URI'))
+target_metadata = current_app.extensions['migrate'].db.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(url=url)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+
+    # this callback is used to prevent an auto-migration from being generated
+    # when there are no changes to the schema
+    # reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
+    def process_revision_directives(context, revision, directives):
+        if getattr(config.cmd_opts, 'autogenerate', False):
+            script = directives[0]
+            if script.upgrade_ops.is_empty():
+                directives[:] = []
+                logger.info('No changes in schema detected.')
+
+    engine = engine_from_config(config.get_section(config.config_ini_section),
+                                prefix='sqlalchemy.',
+                                poolclass=pool.NullPool)
+
+    connection = engine.connect()
+    context.configure(connection=connection,
+                      target_metadata=target_metadata,
+                      process_revision_directives=process_revision_directives,
+                      **current_app.extensions['migrate'].configure_args)
+
+    try:
+        with context.begin_transaction():
+            context.run_migrations()
+    finally:
+        connection.close()
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/2b017edaa91f_add_language_to_posts.py

@@ -0,0 +1,28 @@
+"""add language to posts
+
+Revision ID: 2b017edaa91f
+Revises: ae346256b650
+Create Date: 2017-10-04 22:48:34.494465
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '2b017edaa91f'
+down_revision = 'ae346256b650'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('post', sa.Column('language', sa.String(length=5), nullable=True))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('post', 'language')
+    # ### end Alembic commands ###

migrations/versions/37f06a334dbf_new_fields_in_user_model.py

@@ -0,0 +1,30 @@
+"""new fields in user model
+
+Revision ID: 37f06a334dbf
+Revises: 780739b227a7
+Create Date: 2017-09-14 10:54:13.865401
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '37f06a334dbf'
+down_revision = '780739b227a7'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('user', sa.Column('about_me', sa.String(length=140), nullable=True))
+    op.add_column('user', sa.Column('last_seen', sa.DateTime(), nullable=True))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('user', 'last_seen')
+    op.drop_column('user', 'about_me')
+    # ### end Alembic commands ###

migrations/versions/780739b227a7_posts_table.py

@@ -0,0 +1,37 @@
+"""posts table
+
+Revision ID: 780739b227a7
+Revises: e517276bb1c2
+Create Date: 2017-09-11 12:23:25.496587
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '780739b227a7'
+down_revision = 'e517276bb1c2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('post',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('body', sa.String(length=140), nullable=True),
+    sa.Column('timestamp', sa.DateTime(), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=True),
+    sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_post_timestamp'), 'post', ['timestamp'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_post_timestamp'), table_name='post')
+    op.drop_table('post')
+    # ### end Alembic commands ###

migrations/versions/834b1a697901_user_tokens.py

@@ -0,0 +1,32 @@
+"""user tokens
+
+Revision ID: 834b1a697901
+Revises: c81bac34faab
+Create Date: 2017-11-05 18:41:07.996137
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '834b1a697901'
+down_revision = 'c81bac34faab'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('user', sa.Column('token', sa.String(length=32), nullable=True))
+    op.add_column('user', sa.Column('token_expiration', sa.DateTime(), nullable=True))
+    op.create_index(op.f('ix_user_token'), 'user', ['token'], unique=True)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_user_token'), table_name='user')
+    op.drop_column('user', 'token_expiration')
+    op.drop_column('user', 'token')
+    # ### end Alembic commands ###

migrations/versions/ae346256b650_followers.py

@@ -0,0 +1,33 @@
+"""followers
+
+Revision ID: ae346256b650
+Revises: 37f06a334dbf
+Create Date: 2017-09-17 15:41:30.211082
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'ae346256b650'
+down_revision = '37f06a334dbf'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('followers',
+    sa.Column('follower_id', sa.Integer(), nullable=True),
+    sa.Column('followed_id', sa.Integer(), nullable=True),
+    sa.ForeignKeyConstraint(['followed_id'], ['user.id'], ),
+    sa.ForeignKeyConstraint(['follower_id'], ['user.id'], )
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('followers')
+    # ### end Alembic commands ###

migrations/versions/c81bac34faab_tasks.py

@@ -0,0 +1,38 @@
+"""tasks
+
+Revision ID: c81bac34faab
+Revises: f7ac3d27bb1d
+Create Date: 2017-11-23 10:56:49.599779
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'c81bac34faab'
+down_revision = 'f7ac3d27bb1d'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('task',
+    sa.Column('id', sa.String(length=36), nullable=False),
+    sa.Column('name', sa.String(length=128), nullable=True),
+    sa.Column('description', sa.String(length=128), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=True),
+    sa.Column('complete', sa.Boolean(), nullable=True),
+    sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_task_name'), 'task', ['name'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_task_name'), table_name='task')
+    op.drop_table('task')
+    # ### end Alembic commands ###

migrations/versions/d049de007ccf_private_messages.py

@@ -0,0 +1,41 @@
+"""private messages
+
+Revision ID: d049de007ccf
+Revises: 834b1a697901
+Create Date: 2017-11-12 23:30:28.571784
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'd049de007ccf'
+down_revision = '2b017edaa91f'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('message',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('sender_id', sa.Integer(), nullable=True),
+    sa.Column('recipient_id', sa.Integer(), nullable=True),
+    sa.Column('body', sa.String(length=140), nullable=True),
+    sa.Column('timestamp', sa.DateTime(), nullable=True),
+    sa.ForeignKeyConstraint(['recipient_id'], ['user.id'], ),
+    sa.ForeignKeyConstraint(['sender_id'], ['user.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_message_timestamp'), 'message', ['timestamp'], unique=False)
+    op.add_column('user', sa.Column('last_message_read_time', sa.DateTime(), nullable=True))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('user', 'last_message_read_time')
+    op.drop_index(op.f('ix_message_timestamp'), table_name='message')
+    op.drop_table('message')
+    # ### end Alembic commands ###

migrations/versions/e517276bb1c2_users_table.py

@@ -0,0 +1,38 @@
+"""users table
+
+Revision ID: e517276bb1c2
+Revises: 
+Create Date: 2017-09-11 11:23:05.566844
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'e517276bb1c2'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('user',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('username', sa.String(length=64), nullable=True),
+    sa.Column('email', sa.String(length=120), nullable=True),
+    sa.Column('password_hash', sa.String(length=128), nullable=True),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_user_email'), 'user', ['email'], unique=True)
+    op.create_index(op.f('ix_user_username'), 'user', ['username'], unique=True)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_user_username'), table_name='user')
+    op.drop_index(op.f('ix_user_email'), table_name='user')
+    op.drop_table('user')
+    # ### end Alembic commands ###

migrations/versions/f7ac3d27bb1d_notifications.py

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+"""notifications
+
+Revision ID: f7ac3d27bb1d
+Revises: d049de007ccf
+Create Date: 2017-11-22 19:48:39.945858
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'f7ac3d27bb1d'
+down_revision = 'd049de007ccf'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('notification',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('name', sa.String(length=128), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=True),
+    sa.Column('timestamp', sa.Float(), nullable=True),
+    sa.Column('payload_json', sa.Text(), nullable=True),
+    sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_notification_name'), 'notification', ['name'], unique=False)
+    op.create_index(op.f('ix_notification_timestamp'), 'notification', ['timestamp'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_notification_timestamp'), table_name='notification')
+    op.drop_index(op.f('ix_notification_name'), table_name='notification')
+    op.drop_table('notification')
+    # ### end Alembic commands ###

requirements.txt

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+alembic==1.6.5
+Babel==2.9.1
+blinker==1.4
+certifi==2021.5.30
+chardet==4.0.0
+click==8.0.1
+dnspython==2.1.0
+dominate==2.6.0
+elasticsearch==7.13.3
+email-validator==1.1.3
+Flask==2.0.1
+Flask-Babel==2.0.0
+Flask-Bootstrap==3.3.7.1
+Flask-HTTPAuth==4.4.0
+Flask-Login==0.5.0
+Flask-Mail==0.9.1
+Flask-Migrate==3.0.1
+Flask-Moment==1.0.1
+Flask-SQLAlchemy==2.5.1
+Flask-WTF==0.15.1
+greenlet==1.1.0
+httpie==2.4.0
+idna==2.10
+itsdangerous==2.0.1
+Jinja2==3.0.1
+langdetect==1.0.9
+Mako==1.1.4
+MarkupSafe==2.0.1
+Pygments==2.9.0
+PyJWT==2.1.0
+PySocks==1.7.1
+python-dateutil==2.8.1
+python-dotenv==0.18.0
+python-editor==1.0.4
+pytz==2021.1
+redis==3.5.3
+requests==2.25.1
+requests-toolbelt==0.9.1
+rq==1.9.0
+six==1.16.0
+SQLAlchemy==1.4.20
+urllib3==1.26.6
+visitor==0.1.3
+Werkzeug==2.0.1
+WTForms==2.3.3
+
+# requirements for Heroku
+#psycopg2==2.9.1
+#gunicorn==20.1.0

tests.py

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+#!/usr/bin/env python
+from datetime import datetime, timedelta
+import unittest
+from app import create_app, db
+from app.models import User, Post
+from config import Config
+
+
+class TestConfig(Config):
+    TESTING = True
+    SQLALCHEMY_DATABASE_URI = 'sqlite://'
+    ELASTICSEARCH_URL = None
+
+
+class UserModelCase(unittest.TestCase):
+    def setUp(self):
+        self.app = create_app(TestConfig)
+        self.app_context = self.app.app_context()
+        self.app_context.push()
+        db.create_all()
+
+    def tearDown(self):
+        db.session.remove()
+        db.drop_all()
+        self.app_context.pop()
+
+    def test_password_hashing(self):
+        u = User(username='susan')
+        u.set_password('cat')
+        self.assertFalse(u.check_password('dog'))
+        self.assertTrue(u.check_password('cat'))
+
+    def test_avatar(self):
+        u = User(username='john', email='john@example.com')
+        self.assertEqual(u.avatar(128), ('https://www.gravatar.com/avatar/'
+                                         'd4c74594d841139328695756648b6bd6'
+                                         '?d=identicon&s=128'))
+
+    def test_follow(self):
+        u1 = User(username='john', email='john@example.com')
+        u2 = User(username='susan', email='susan@example.com')
+        db.session.add(u1)
+        db.session.add(u2)
+        db.session.commit()
+        self.assertEqual(u1.followed.all(), [])
+        self.assertEqual(u1.followers.all(), [])
+
+        u1.follow(u2)
+        db.session.commit()
+        self.assertTrue(u1.is_following(u2))
+        self.assertEqual(u1.followed.count(), 1)
+        self.assertEqual(u1.followed.first().username, 'susan')
+        self.assertEqual(u2.followers.count(), 1)
+        self.assertEqual(u2.followers.first().username, 'john')
+
+        u1.unfollow(u2)
+        db.session.commit()
+        self.assertFalse(u1.is_following(u2))
+        self.assertEqual(u1.followed.count(), 0)
+        self.assertEqual(u2.followers.count(), 0)
+
+    def test_follow_posts(self):
+        # create four users
+        u1 = User(username='john', email='john@example.com')
+        u2 = User(username='susan', email='susan@example.com')
+        u3 = User(username='mary', email='mary@example.com')
+        u4 = User(username='david', email='david@example.com')
+        db.session.add_all([u1, u2, u3, u4])
+
+        # create four posts
+        now = datetime.utcnow()
+        p1 = Post(body="post from john", author=u1,
+                  timestamp=now + timedelta(seconds=1))
+        p2 = Post(body="post from susan", author=u2,
+                  timestamp=now + timedelta(seconds=4))
+        p3 = Post(body="post from mary", author=u3,
+                  timestamp=now + timedelta(seconds=3))
+        p4 = Post(body="post from david", author=u4,
+                  timestamp=now + timedelta(seconds=2))
+        db.session.add_all([p1, p2, p3, p4])
+        db.session.commit()
+
+        # setup the followers
+        u1.follow(u2)  # john follows susan
+        u1.follow(u4)  # john follows david
+        u2.follow(u3)  # susan follows mary
+        u3.follow(u4)  # mary follows david
+        db.session.commit()
+
+        # check the followed posts of each user
+        f1 = u1.followed_posts().all()
+        f2 = u2.followed_posts().all()
+        f3 = u3.followed_posts().all()
+        f4 = u4.followed_posts().all()
+        self.assertEqual(f1, [p2, p4, p1])
+        self.assertEqual(f2, [p2, p3])
+        self.assertEqual(f3, [p3, p4])
+        self.assertEqual(f4, [p4])
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)