Chapter 9

app/routes.py

@@ -3,7 +3,13 @@ from flask import render_template, flash, redirect, url_for, request
 from flask_login import current_user, login_user, logout_user, login_required
 from werkzeug.urls import url_parse
 from app import app, db
-from app.forms import LoginForm, RegistrationForm, EditProfileForm, EmptyForm, PostForm
+from app.forms import (
+    LoginForm,
+    RegistrationForm,
+    EditProfileForm,
+    EmptyForm,
+    PostForm,
+)
 from app.models import User, Post
 
 
@@ -14,8 +20,8 @@ def before_request():
         db.session.commit()
 
 
-@app.route('/', methods=['GET', 'POST'])
+@app.route("/", methods=["GET", "POST"])
-@app.route('/index', methods=['GET', 'POST'])
+@app.route("/index", methods=["GET", "POST"])
 @login_required
 def index():
     form = PostForm()
@@ -23,11 +29,26 @@ def index():
         post = Post(body=form.post.data, author=current_user)
         db.session.add(post)
         db.session.commit()
-        flash('Your post is now live!')
+        flash("Your post is now live!")
-        return redirect(url_for('index'))
+        return redirect(url_for("index"))
-    posts = current_user.followed_posts().all()
+    page = request.args.get("page", 1, type=int)
-    return render_template("index.html", title='Home Page', form=form,
+    posts = current_user.followed_posts().paginate(
-                           posts=posts)
+        page=page, per_page=app.config["POSTS_PER_PAGE"], error_out=False
+    )
+    next_url = (
+        url_for("index", page=posts.next_num) if posts.has_next else None
+    )
+    prev_url = (
+        url_for("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,
+    )
 
 
 @app.route("/login", methods=["GET", "POST"])
@@ -73,12 +94,29 @@ def register():
 @login_required
 def user(username):
     user = User.query.filter_by(username=username).first_or_404()
-    posts = [
+    page = request.args.get("page", 1, type=int)
-        {"author": user, "body": "Test post #1"},
+    posts = user.posts.order_by(Post.timestamp.desc()).paginate(
-        {"author": user, "body": "Test post #2"},
+        page=page, per_page=app.config["POSTS_PER_PAGE"], error_out=False
-    ]
+    )
+    next_url = (
+        url_for("user", username=user.username, page=posts.next_num)
+        if posts.has_next
+        else None
+    )
+    prev_url = (
+        url_for("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, form=form)
+    return render_template(
+        "user.html",
+        user=user,
+        posts=posts.items,
+        next_url=next_url,
+        prev_url=prev_url,
+        form=form,
+    )
 
 
 @app.route("/edit_profile", methods=["GET", "POST"])
@@ -138,8 +176,24 @@ def unfollow(username):
     else:
         return redirect(url_for("index"))
 
-@app.route('/explore')
+
+@app.route("/explore")
 @login_required
 def explore():
-    posts = Post.query.order_by(Post.timestamp.desc()).all()
+    page = request.args.get("page", 1, type=int)
-    return render_template('index.html', title='Explore', posts=posts)
+    posts = Post.query.order_by(Post.timestamp.desc()).paginate(
+        page=page, per_page=app.config["POSTS_PER_PAGE"], error_out=False
+    )
+    next_url = (
+        url_for("explore", page=posts.next_num) if posts.has_next else None
+    )
+    prev_url = (
+        url_for("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,
+    )

app/templates/index.html

@@ -16,6 +16,12 @@
     </form>
   {% endif %}
   {% for post in posts %}
-    {% include "_post.html" %}
+      {% include '_post.html' %}
   {% endfor %}
+  {% if prev_url %}
+    <a href="{{ prev_url }}">Newer posts</a>
+  {% endif %}
+  {% if next_url %}
+    <a href="{{ next_url }}">Older posts</a>
+  {% endif %}
 {% endblock %}s

app/templates/user.html

@@ -41,4 +41,10 @@
   {% for post in posts %}
     {% include '_post.html' %}
   {% endfor %}
+  {% if prev_url %}
+  <a href="{{ prev_url }}">Newer posts</a>
+  {% endif %}
+  {% if next_url %}
+  <a href="{{ next_url }}">Older posts</a>
+  {% endif %}
 {% endblock %}

config.py

@@ -15,3 +15,4 @@ class Config(object):
     MAIL_USERNAME = os.environ.get("MAIL_USERNAME")
     MAIL_PASSWORD = os.environ.get("MAIL_PASSWORD")
     ADMINS = ["your-email@example.com"]
+    POSTS_PER_PAGE = 25