multiple_apps.md

layout	title
default	Django style multiple apps with web.py

Django style multiple apps with web.py

Here is a hack to support decoupling urls for multiple applications using web.py

suppose we have two applications blog and wiki and we want to put them in same project.

This is the main driver.

"""run.py"""    import blog
import wiki
import delegate

mapping = (
    ("/blog", blog.urls, blog),
    ("/wiki", wiki.urls, wiki)
)

if __name__ == "__main__":
    delegate.run(mapping)

The wiki application:

"""wiki.py"""
urls = (
    "/", "welcome",
    "/hello", "hello"    )

class welcome:
    def GET(self):
        print "welcome wiki"
class hello:
    def GET(self):
        print "hello wiki"

The blog application:

"""blog.py"""
urls = (
    "/", "welcome",
    "/hello", "hello"    )

class welcome:
    def GET(self):
        print "welcome blog"
class hello:
    def GET(self):
        print "hello blog"        

And this is the hack for supporting multiple application abstration.

"""delegate.py"""    import web
import types

def delegate_apps(mapping):
    """Delegates appropriate app based on prefix.
    `mapping` should be tuple of (prefix, urls, fvars).
    """        def f():
        for prefix, urls, fvars in mapping:
            if type(fvars) == types.ModuleType:
                fvars = fvars.__dict__

            if web.ctx.path.startswith(prefix):
                path = web.ctx.path[len(prefix):]

                # it will be better if web.request.handle takes path also as argument.
                # return web.request.handle(mapping, fvars, path)
                
                web.ctx.path = path
                return web.request.handle(urls, fvars)
        else:
            return web.notfound()

    return f

def run(mapping):
    """Starts web.py server with the specified mapping.
    `mapping` should be tuple of (prefix, urls, fvars).
    """        handler = delegate_apps(mapping)
    web.run(handler, {})