cherrypy handle all request with one function or class

Question

i'd like to use cherrypy but i don't want to use the normal dispatcher, i'd like to have a function that catch all the requests and then perform my code. I think that i have to implement my own dispatcher but i can't find any valid example. Can you help me by posting some code or link ?

Thanks

Foxtrot

Answer 1

make a default function:

import cherrypy

class server(object):
        @cherrypy.expose
        def default(self,*args,**kwargs):
                return "It works!"

cherrypy.quickstart(server())

Tynes

Works fine! and helped me too. – Restricted

Answer 2

What you ask can be done with routes and defining a custom dispatcher

http://tools.cherrypy.org/wiki/RoutesUrlGeneration

Something like the following. Note the class instantiation assigned to a variable that is used as the controller for all routes, otherwise you will get multiple instances of your class. This differs from the example in the link, but I think is more what you want.

class Root:
    def index(self):
        <cherrpy stuff>
        return some_variable

dispatcher = None
root = Root()

def setup_routes():
    d = cherrypy.dispatch.RoutesDispatcher()
    d.connect('blog', 'myblog/:entry_id/:action', controller=root)
    d.connect('main', ':action', controller=root)
    dispatcher = d
    return dispatcher

conf = {'/': {'request.dispatch': setup_routes()}}

Hope that helps : )

Torture

am i wrong or this solution assume that i already know all the available path when cherrypy start ? this is not my case, i have to query the database every time to find if a particular url is valid and what to display – Foxtrot

Yes it does assume that you already know the paths that you are serving from. If you have those paths in a database you could construct the paths at app startup in the dispatch function. Its hard to give you a full solution without knowing more but you should be able to loop through a cursor and point all paths to your instantiated class. Hopefully your paths are not dynamic. This solution would require an app restart for every path change. – Torture

Answer 3

Here's a quick example for CherryPy 3.2:

from cherrypy._cpdispatch import LateParamPageHandler

class SingletonDispatcher(object):

    def __init__(self, func):
        self.func = func

    def set_config(self, path_info):
        # Get config for the root object/path.
        request = cherrypy.serving.request
        request.config = base = cherrypy.config.copy()
        curpath = ""

        def merge(nodeconf):
            if 'tools.staticdir.dir' in nodeconf:
                nodeconf['tools.staticdir.section'] = curpath or "/"
            base.update(nodeconf)

        # Mix in values from app.config.
        app = request.app
        if "/" in app.config:
            merge(app.config["/"])

        for segment in path_info.split("/")[:-1]:
            curpath = "/".join((curpath, segment))
            if curpath in app.config:
                merge(app.config[curpath])

    def __call__(self, path_info):
        """Set handler and config for the current request."""
        self.set_config(path_info)

        # Decode any leftover %2F in the virtual_path atoms.
        vpath = [x.replace("%2F", "/") for x in path_info.split("/") if x]
        cherrypy.request.handler = LateParamPageHandler(self.func, *vpath)

Then just set it in config for the paths you intend:

[/single]
request.dispatch = myapp.SingletonDispatcher(myapp.dispatch_func)

...where "dispatch_func" is your "function that catches all the requests". It will be passed any path segments as positional arguments, and any querystring as keyword arguments.

Hime

Hm, but that won't collect config for you from the Application per URI. I'll see if I can improve the above tomorrow. – Hime

uh maybe i'm too newbie but i can't get your example working, see this gist.github.com/1086473 if i call 127.0.0.1:8080 i get the "hello world" message but what i want is handle other urls that i can't determine at startup and the test() function never get called. Is it possible to catch 404 exceptions to handle all the paths ? – Foxtrot

Sorry about that. I got the vpath messed up. I've fixed the above. – Hime

i've replaced the code in the gist with the new version of your class but it acts exactly like before – Foxtrot