Skip to content

Instantly share code, notes, and snippets.

@deldotdr

deldotdr/web.rewrite.example.py

Created January 25, 2010 23:15
Show Gist options
  • Save deldotdr/286376 to your computer and use it in GitHub Desktop.
Save deldotdr/286376 to your computer and use it in GitHub Desktop.
Download ZIP
Raw
web.rewrite.example.py
"""
run python web.rewrite.example.py
and then open a browser to localhost:8080/data/foo/bar
The two segments of the path below /data are transformed into query
arguments using the rewrite function pathToArgs.
The root resource is wrapped with the rewrite resource
The second arg to RewriterResource is the rewrite function.
The rewrite function can be thought of as a rule + an action:
If the request satisfies the rule, the request is rewritten.
This rewrite happens before the web framework passes the request object to
any resource in root (including root itself).
It is possible to give more than one rewrite function; they will all have
a chance to rewrite the request object.
If you look at pathToArgs, everything below the if statement is the
rewrite action.
Part of the action is self explanatory:
- request.args is added (now the handling resources have access to
request.args)
- request.path is explicitly set to '/data' The intent of this
rewrite implies /data is a leaf resource.
And part of it is a little confusing
- request.postpath -- this is not as straight forward. When the
Request object is first created, the raw HTTP headers of the actual
request from your browser are processed. Part of that involves
splitting the PATH on '/' and storing that in request.postpath.
Then, for every hop down a resource tree, the head element of
postpath is popped and appended to prepath.
request.path represents the full requested path.
"""
from twisted.web import resource
from twisted.web import rewrite
from twisted.web import server
from twisted.internet import reactor
class GenericResource(resource.Resource):
def render(self, request):
return "dummy resource page"
class DataResource(resource.Resource):
def render(self, request):
"""request.args are where GET request args are stored.
(From docs) For example, for a URI with
'foo=bar&foo=baz&quux=spam'
for its query part, args will be
{'foo': ['bar', 'baz'], 'quux': ['spam']}
"""
print request.args
request.write(str(request.args))
return ""
def pathToArgs(request):
"""assume segments of path following "data" are values for the keys:
- sta
- orid
localhost:8008/data/109C/39495/
->
localhost:8008/data?sta=109C&orid=39495
"""
if len(request.postpath) == 3 and request.postpath[0] == 'data':
sta = request.postpath[1]
orid = request.postpath[2]
request.args = {'sta':[sta], 'orid':[orid]}
request.postpath = ['data']
request.path = '/data'
root = GenericResource()
root.putChild('', root)
root.putChild('test', GenericResource())
root.putChild('data', DataResource())
rewrite_root = rewrite.RewriterResource(root, pathToArgs)
site = server.Site(rewrite_root)
reactor.listenTCP(8080, site)
reactor.run()
Raw
web.rewrite.example2.py
"""
run python web.rewrite.example.py
and then open a browser to localhost:8080/data/foo/bar
The two segments of the path below /data are transformed into query
arguments using the rewrite function pathToArgs.
The root resource is wrapped with the rewrite resource
The second arg to RewriterResource is the rewrite function.
The rewrite function can be thought of as a rule + an action:
If the request satisfies the rule, the request is rewritten.
This rewrite happens before the web framework passes the request object to
any resource in root (including root itself).
It is possible to give more than one rewrite function; they will all have
a chance to rewrite the request object.
If you look at pathToArgs, everything below the if statement is the
rewrite action.
Part of the action is self explanatory:
- request.args is added (now the handling resources have access to
request.args)
- request.path is explicitly set to '/data' The intent of this
rewrite implies /data is a leaf resource.
And part of it is a little confusing
- request.postpath -- this is not as straight forward. When the
Request object is first created, the raw HTTP headers of the actual
request from your browser are processed. Part of that involves
splitting the PATH on '/' and storing the resulting list in
request.postpath. Then, for every step down a resource tree, the
head element of postpath is popped and appended to prepath.
request.path represents the full requested path.
In this second example, there are two rewrite rules.
test2Data looks for /test/data/variable
When this rule matches, it rewrites the request to a form that matches the
rule in pathToArgs: /data/variable/constant
The RewriterResource wrapper has three arguments now:
the resource tree to be wrapped
two rewrite functions
The order of the last two arguemnts matters. In this case, the test2Data
rewrite only makes sense if it is applied before the pathToArgs rewrite.
If you switch the order of those two arguments, it wont work the same way;
a request to the path /test/data/something will never be handled by the
DataResource.
"""
from twisted.web import resource
from twisted.web import rewrite
from twisted.web import server
from twisted.internet import reactor
class GenericResource(resource.Resource):
def render(self, request):
return "dummy resource page"
class DataResource(resource.Resource):
def render(self, request):
"""request.args are where GET request args are stored.
(From docs) For example, for a URI with
'foo=bar&foo=baz&quux=spam'
for its query part, args will be
{'foo': ['bar', 'baz'], 'quux': ['spam']}
"""
print request.args
request.write(str(request.args))
return ""
def pathToArgs(request):
"""assume segments of path following "data" are values for the keys:
- sta
- orid
localhost:8008/data/109C/39495/
->
localhost:8008/data?sta=109C&orid=39495
"""
if len(request.postpath) == 3 and request.postpath[0] == 'data':
sta = request.postpath[1]
orid = request.postpath[2]
request.args = {'sta':[sta], 'orid':[orid]}
request.postpath = ['data']
request.path = '/data'
def test2Data(request):
if request.postpath[0] == 'test':
if len(request.postpath) > 2 and request.postpath[1] == 'data':
if request.postpath:
param =request.postpath[2]
request.postpath = ['data', param,'constant']
request.path = '/data'
root = GenericResource()
root.putChild('', root)
root.putChild('test', GenericResource())
root.putChild('data', DataResource())
rewrite_root = rewrite.RewriterResource(root, test2Data, pathToArgs)
site = server.Site(rewrite_root)
reactor.listenTCP(8080, site)
reactor.run()
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment