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Changing an application's favicon in CherryPy

While it's technically simple, I found the documentation about changing the favicon of a CherryPy site to be somewhat confusing. This is my attempt to clear it up a bit.

There are two different ways of supplying config information:

  1. Config information from a text file (you can pass a filename or open file handle).
  2. Config information from a Python dictionary in your code.

I'm going to concentrate on the second method for now.

Here's my config dictionary.

config = {    '/': {        'log.error_file': os.path.join(os.path.dirname(__file__), 'site.log'),        'environment': 'production',    },    '/favicon.ico': {        'tools.staticfile.on': True,        'tools.staticfile.filename': '/path/to/favicon.ico',    }}

Notice that the dictionary contains two sub-dictionaries, one for '/' and one for '/favicon.ico'.

'/' is where global application configuration goes. In this case, we're setting where the error log goes and what type of environment we're running.

CherryPy has a default favicon.ico that it will use if one isn't specified. The second part ('/favicon.ico') of the dictionary overrides that default and specifies the location of a different file to use.

My last post about configuring CherryPy to run with Apache defined a method called start() that was responsible for starting the CherryPy engine when called from apache.

To use this new config setup, we're going to change that start() method slightly to this:

def start():    cherrypy.tree.mount(root, '/', config=config)    cherrypy.engine.start()

Previously, we passed the '/' config parameters to cherrypy.config.update().

Now we pass the entire config dictionary along. This approach is nice because we can also store application configuration info (that CherryPy doesn't necessarily care about) and then get values out of it by using the dictionary.

Another addition to this approach is to configure an area for serving static content (CSS, javascript, images, etc). That can easily be done by adding the following item to the config dictionary:

'/static': {        'tools.staticdir.on': True,        'tools.staticdir.dir': os.path.join(os.path.dirname(__file__), 'static')    },

This adds the path /static (looking for the directory static in the same directory as the app) and sets it as a static dir. Now anything that uses the url /static will point to files within the static directory.

For example, this will now link to the static file global.css rather than looking for a CherryPy route.

<link rel="stylesheet" type="text/css" href="/static/css/global.css" media="screen"><link>