Chapter 12: Followers in the application (12b)

app/main/views.py

@@ -5,7 +5,7 @@
 from .forms import EditProfileForm, EditProfileAdminForm, PostForm
 from .. import db
 from ..models import Permission, Role, User, Post
-from ..decorators import admin_required
+from ..decorators import admin_required, permission_required
 
 
 @main.route('/', methods=['GET', 'POST'])
@@ -106,3 +106,71 @@ def edit(id):
         return redirect(url_for('.post', id=post.id))
     form.body.data = post.body
     return render_template('edit_post.html', form=form)
+
+
+@main.route('/follow/<username>')
+@login_required
+@permission_required(Permission.FOLLOW)
+def follow(username):
+    user = User.query.filter_by(username=username).first()
+    if user is None:
+        flash('Invalid user.')
+        return redirect(url_for('.index'))
+    if current_user.is_following(user):
+        flash('You are already following this user.')
+        return redirect(url_for('.user', username=username))
+    current_user.follow(user)
+    db.session.commit()
+    flash('You are now following %s.' % username)
+    return redirect(url_for('.user', username=username))
+
+
+@main.route('/unfollow/<username>')
+@login_required
+@permission_required(Permission.FOLLOW)
+def unfollow(username):
+    user = User.query.filter_by(username=username).first()
+    if user is None:
+        flash('Invalid user.')
+        return redirect(url_for('.index'))
+    if not current_user.is_following(user):
+        flash('You are not following this user.')
+        return redirect(url_for('.user', username=username))
+    current_user.unfollow(user)
+    db.session.commit()
+    flash('You are not following %s anymore.' % username)
+    return redirect(url_for('.user', username=username))
+
+
+@main.route('/followers/<username>')
+def followers(username):
+    user = User.query.filter_by(username=username).first()
+    if user is None:
+        flash('Invalid user.')
+        return redirect(url_for('.index'))
+    page = request.args.get('page', 1, type=int)
+    pagination = user.followers.paginate(
+        page, per_page=current_app.config['FLASKY_FOLLOWERS_PER_PAGE'],
+        error_out=False)
+    follows = [{'user': item.follower, 'timestamp': item.timestamp}
+               for item in pagination.items]
+    return render_template('followers.html', user=user, title="Followers of",
+                           endpoint='.followers', pagination=pagination,
+                           follows=follows)
+
+
+@main.route('/followed_by/<username>')
+def followed_by(username):
+    user = User.query.filter_by(username=username).first()
+    if user is None:
+        flash('Invalid user.')
+        return redirect(url_for('.index'))
+    page = request.args.get('page', 1, type=int)
+    pagination = user.followed.paginate(
+        page, per_page=current_app.config['FLASKY_FOLLOWERS_PER_PAGE'],
+        error_out=False)
+    follows = [{'user': item.followed, 'timestamp': item.timestamp}
+               for item in pagination.items]
+    return render_template('followers.html', user=user, title="Followed by",
+                           endpoint='.followed_by', pagination=pagination,
+                           follows=follows)

app/models.py

@@ -204,13 +204,13 @@ def gravatar(self, size=100, default='identicon', rating='g'):
 
     def follow(self, user):
         if not self.is_following(user):
-            f = Follow(followed=user)
-            self.followed.append(f)
+            f = Follow(follower=self, followed=user)
+            db.session.add(f)
 
     def unfollow(self, user):
         f = self.followed.filter_by(followed_id=user.id).first()
         if f:
-            self.followed.remove(f)
+            db.session.delete(f)
 
     def is_following(self, user):
         if user.id is None:

app/static/styles.css

@@ -63,4 +63,6 @@ div.flask-pagedown-preview h3 {
 .post-body h3 {
     font-size: 120%;
 }
-
+.table.followers tr {
+    border-bottom: 1px solid #e0e0e0;
+}

app/templates/followers.html

@@ -0,0 +1,27 @@
+{% extends "base.html" %}
+{% import "_macros.html" as macros %}
+
+{% block title %}Flasky - {{ title }} {{ user.username }}{% endblock %}
+
+{% block page_content %}
+<div class="page-header">
+    <h1>{{ title }} {{ user.username }}</h1>
+</div>
+<table class="table table-hover followers">
+    <thead><tr><th>User</th><th>Since</th></tr></thead>
+    {% for follow in follows %}
+    <tr>
+        <td>
+            <a href="{{ url_for('.user', username = follow.user.username) }}">
+                <img class="img-rounded" src="{{ follow.user.gravatar(size=32) }}">
+                {{ follow.user.username }}
+            </a>
+        </td>
+        <td>{{ moment(follow.timestamp).format('L') }}</td>
+    </tr>
+    {% endfor %}
+</table>
+<div class="pagination">
+    {{ macros.pagination_widget(pagination, endpoint, username = user.username) }}
+</div>
+{% endblock %}

app/templates/user.html

@@ -22,6 +22,20 @@ <h1>{{ user.username }}</h1>
         {% if user.about_me %}<p>{{ user.about_me }}</p>{% endif %}
         <p>Member since {{ moment(user.member_since).format('L') }}. Last seen {{ moment(user.last_seen).fromNow() }}.</p>
         <p>{{ user.posts.count() }} blog posts.</p>
+        <p>
+            {% if current_user.can(Permission.FOLLOW) and user != current_user %}
+                {% if not current_user.is_following(user) %}
+                <a href="{{ url_for('.follow', username=user.username) }}" class="btn btn-primary">Follow</a>
+                {% else %}
+                <a href="{{ url_for('.unfollow', username=user.username) }}" class="btn btn-default">Unfollow</a>
+                {% endif %}
+            {% endif %}
+            <a href="{{ url_for('.followers', username=user.username) }}">Followers: <span class="badge">{{ user.followers.count() }}</span></a>
+            <a href="{{ url_for('.followed_by', username=user.username) }}">Following: <span class="badge">{{ user.followed.count() }}</span></a>
+            {% if current_user.is_authenticated and user != current_user and user.is_following(current_user) %}
+            | <span class="label label-default">Follows you</span>
+            {% endif %}
+        </p>
         <p>
             {% if user == current_user %}
             <a class="btn btn-default" href="{{ url_for('.edit_profile') }}">Edit Profile</a>
@@ -39,4 +53,4 @@ <h3>Posts by {{ user.username }}</h3>
     {{ macros.pagination_widget(pagination, '.user', username=user.username) }}
 </div>
 {% endif %}
-{% endblock %}
+{% endblock %}

config.py

@@ -15,6 +15,7 @@ class Config:
     FLASKY_ADMIN = os.environ.get('FLASKY_ADMIN')
     SQLALCHEMY_TRACK_MODIFICATIONS = False
     FLASKY_POSTS_PER_PAGE = 20
+    FLASKY_FOLLOWERS_PER_PAGE = 50
 
     @staticmethod
     def init_app(app):