External JavaScript file is not getting added when running on Flask

Tony picture Tony · Feb 5, 2013 · Viewed 67k times · Source

I have an HTML file named showMap.html:

<!DOCTYPE html>
<html>

<head>
  <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
  <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
  <title>Map</title>
  <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false">
  </script>
  <script type="text/javascript" src="js/map.js"></script>
</head>

<body onload="showPosition()">
  <div id="map_canvas" style="width:500px;height:500px;"></div>
</body>

</html>

And another JavaScript file map.js is placed in the js folder of the same directory.

This code works fine when the HTML file is loaded, but this does not work when I run it in the server.

I use Python's Flask framework for back-end programming and the funny thing is that the same thing will work well if I expand the JavaScript code inside the HTML file. The only problem is with the external file.

Answer

Martijn Pieters picture Martijn Pieters · Feb 5, 2013

Serve the map.js file as a static resource:

  • move the file to a static/ subdirectory of your package

  • generate a static URL for it in a Jinja2 template like so:

     <script type="text/javascript"
             src="{{ url_for('static', filename='map.js') }}"></script>
    

The filename parameter takes a relative path; you can use subdirectories was needed.