How to load a javascript or css file into a BottlePy template?

eltorrero picture eltorrero · Aug 8, 2011 · Viewed 18k times · Source

I am trying to return a html template with BottlePy. And this works fine. But if I insert a javascript file like this in my tpl-file:

<script type="text/javascript" src="js/main.js" charset="utf-8"></script>

I get an 404 error. (Failed to load resource: the server responded with a status of 404 (Not Found))

Does anyone know how to fix this problem?

Here is my script file:

from bottle import route, run, view

@route('/')
@view('index')
def index():
    return dict()
run(host='localhost', port=8080)

And that is the template file, located in "./views" subfolder.

<!DOCTYPE html>
<html lang="de">
    <head>
        <meta charset="utf-8" />
        <script type="text/javascript" src="js/main.js" charset="utf-8"></script>
    </head>
    <body>
    </body>
</html>

Maybe it is the "rootPath/js/main.js" from the development server where it looks for my js-file?

The structure of the files is:

app.py
-js
 main.js
-views
 index.tpl

Thanks.

Answer

Helgi picture Helgi · Aug 8, 2011

Well, first, you need your dev server to actually serve main.js, otherwise it won't be available for the browser.

It's customary to put all .js and .css files under the static directory in small web apps, so your layout should look like this:

  app.py
- static/
    main.js
- views/
    index.tpl

By no means this exact naming and layout is required, only often used.

Next, you should supply a handler for the static files:

from bottle import static_file

# ...

@route('/static/:path#.+#', name='static')
def static(path):
    return static_file(path, root='static')

This will actuall serve your files under static/ to the browser.

Now, to the last thing. You specified your JavaScript as:

<script type="text/javascript" src="js/main.js" charset="utf-8"></script>

That means the path to .js is relative to the current page. On you development server, the index page (/) will look for .js in /js/main.js, and another page (say, /post/12) will look for it in /post/12/js/main.js, and will sure fail.

Instead, you need to use the get_url function to properly reference static files. Your handler should look like this:

from Bottle import get_url

# ...

@route('/')
@view('index')
def index():
    return { 'get_url': get_url } 

And in index.tpl, .js should be referenced as:

<script type="text/javascript" src="{{ get_url('static', path='main.js') }}" charset="utf-8"></script>

get_url finds a handler with name='static', and calculates the proper path to it. For dev server, this will always be /static/. You can probably even hard-code it in the template, but I don't recommend it for two reasons:

  • You won't be able to mount your app anywhere but under root in production; i.e., when you upload it onto the porduction server, it can be placed under http://example.com/ (root), but not under http://example.com/myapp/.
  • If you change the /static/ dir location, you'll have to search it all over your templates and modify it in every single template.