Chapter 4: Message flashing (4c)

hello.py

@@ -1,4 +1,4 @@
-from flask import Flask, render_template, session, redirect, url_for
+from flask import Flask, render_template, session, redirect, url_for, flash
 from flask_bootstrap import Bootstrap
 from flask_moment import Moment
 from flask_wtf import FlaskForm
@@ -32,6 +32,9 @@ def internal_server_error(e):
 def index():
     form = NameForm()
     if form.validate_on_submit():
+        old_name = session.get('name')
+        if old_name is not None and old_name != form.name.data:
+            flash('Loks like you have changed your name!')
         session['name'] = form.name.data
         return redirect(url_for('index'))
     return render_template('index.html', form=form, name=session.get('name'))

templates/base.html

@@ -32,6 +32,12 @@
 
 {% block content %}
 <div class="container">
+    {% for message in get_flashed_messages() %}
+    <div class="alert alert-warning">
+        <button type="button" class="close" data-dismiss="alert">&times;</button>
+        {{ message }}
+    </div>
+    {% endfor %}
     {% block page_content %}{% endblock %}
 </div>
 {% endblock %}