Serving Multiple Directories

In the previous lesson, we added icons to our web site. However, we were only serving our videos. In this lesson, we will serve the content of our music folder too.

Another Filer

The first step to serve our music is to create another Filer. This is easy for us because we did it in :doc: serve-local-dir lesson. The only difference here is the directory we are serving.

music = Filer(‘/home/user/Music/’, iconer=iconer)

Notice that we have used the same iconer to get the icons. This way, both the video filer and the music filer will use the same icon theme.

Another pattern

Remember that we use the Patterner to forward requests to one of multiple providers based on the url prefix. our music is just another provider. Before we add it to the patterner, let make a few modifications to our previous program. We will make another url prefix plan:

  • video/ will be the prefix for the video filer.
  • music/ will be the prefix for the music filer.
  • __icons__/ will be the prefix for the iconer.

Notice that we changed the prefix for the video filer. Before, it was an empty string. Now, it is video/. Let’s add the providers to our pattener now:

patterner.add('__icons__/', iconer)
patterner.add('video/', video)
patterner.add('music/', music)

We are done. Our program now becomes:

from cofan import *

patterner = Patterner()
iconer = Iconer()
video = Filer('/home/user/Videos/', iconer=iconer)
music = Filer('/home/user/Music/', iconer=iconer)

#add prefixes
patterner.add('__icons__/', iconer)
patterner.add('video/', video)
patterner.add('music/', music)

#make the handler use our patterner as its provider
handler = BaseHandler(patterner)

server = cofan.Server(('localhost', 8000), handler)

server.serve_forever()

Notice that we do not have any provider for the home page url so if we type in the browser address bar localhost:8000, we get a NOT FOUND error. We need to type localhost:8000/video/ or localhost:8000/music/ to open an existing page. That is not so convenient. All websites have a home page right? We are going to fix this in the next lesson.

A last word about prefixes

The prefixes we use in our patterner class can be any regular expression. as mentioned in a previous lesson, any trailing slash is required except for the root url. The pattern video will make the patterner function improperly. Use video/ with a trailing slash instead.

Whenever a request is recieved, the patterner will do the following:

  • It removes the root address and the root address trailing slash. In our example, when the requested address is localhost:8000/video/example.mp4, the patterner will remove localhost:8000/. The url now becomes video/example.mp4.
  • Match each pattern with the beginning of the url. In our example, the url from the previous step is video/example.mp4. The patterner will look for the prefix that the url starts with. The prefix in this case will be video/.
  • Remove the prefix from the url. Now the url becomes only example.mp4.
  • Forwards the request and the new url to the corresponding provider.

Now the video filer will get a request with the url example.mp4 only and will search for this file in its root directory.