added error 404 handling

app.py

@@ -169,6 +169,10 @@ def sorting_by_votes():
     top_voted=mongo.db.repo.find().sort("votes", -1) # top voted first
     return render_template("records.html", records=top_voted)
 
+# handles 404 errors
+@app.errorhandler(404)
+def page_not_found(e):
+    return render_template('404.html'), 404
 
 if __name__ == '__main__':
     port = int(os.getenv('PORT', 5000))

templates/404.html

@@ -0,0 +1,21 @@
+{% extends 'base.html' %} {% block title %}404!{% endblock %}
+
+{% block content %}
+
+<div class="row">
+	<div class="input-field col s12">
+		<h4>Oh dear, this link isn't working!</h4>
+
+		<div class="row">
+			Go somewhere nice:
+			<p>
+				<ul>
+					<li><a href="{{ url_for('get_records')}}"><i class="material-icons left">home</i> Browse records</a></li><br>
+					<li><a href="{{ url_for('show_categories') }}"><i class="material-icons left">folder</i> Browse categories</a></li><br>
+					<li><a href="{{ url_for('add_record') }}"><i class="material-icons left">add</i> Add new link</a></li>
+				</ul>
+			</p>
+		</div>
+	</div>
+</div>
+{% endblock %}