serve file from the download form

app/routes.py

@@ -12,11 +12,11 @@ def index():
 def download():
     form = DownloadForm()
     if form.validate_on_submit():
-        return render_template('download_thanks.html', title='Download', form=form)
+        return render_template('download.html', form=form, filename='test.mp3')
     elif request.method == 'GET':
         form.date.data = datetime.now() - timedelta(hours = 1)
         form.length.data = 60
-    return render_template('download.html', title='Download', form=form)
+    return render_template('download.html', form=form)
 
 @app.route('/download_file/<path:filename>')
 def download_file(filename):

app/templates/download.html

@@ -1,5 +1,13 @@
 {% extends "base.html" %}
 
+
+{% block head %}
+    {{ super() }}
+    {% if filename is defined %}
+    <meta http-equiv="refresh" content="0;URL='download_file/{{ filename }}'" />
+    {% endif %}
+{% endblock %}
+
 {% block app_content %}
     <h1>Download</h1>
     <form action="" method="post" novalidate>

app/templates/download_thanks.html

@@ -1,10 +0,0 @@
-{% extends "base.html" %}
-
-{% block head %}
-  {{ super() }}
-  <meta http-equiv="refresh" content="0;URL='download_file/test.mp3'" />
-{% endblock %}
-
-{% block app_content %}
-    <h1>Thanks!</h1>
-{% endblock %}