mirror of
https://github.com/evilhero/mylar
synced 2024-12-26 01:26:50 +00:00
622 lines
24 KiB
Python
Executable file
622 lines
24 KiB
Python
Executable file
"""CherryPy dispatchers.
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A 'dispatcher' is the object which looks up the 'page handler' callable
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and collects config for the current request based on the path_info, other
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request attributes, and the application architecture. The core calls the
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dispatcher as early as possible, passing it a 'path_info' argument.
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The default dispatcher discovers the page handler by matching path_info
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to a hierarchical arrangement of objects, starting at request.app.root.
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"""
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import string
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import sys
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import types
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import cherrypy
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class PageHandler(object):
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"""Callable which sets response.body."""
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def __init__(self, callable, *args, **kwargs):
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self.callable = callable
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self.args = args
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self.kwargs = kwargs
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def __call__(self):
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try:
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return self.callable(*self.args, **self.kwargs)
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except TypeError:
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x = sys.exc_info()[1]
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try:
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test_callable_spec(self.callable, self.args, self.kwargs)
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except cherrypy.HTTPError:
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raise sys.exc_info()[1]
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except:
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raise x
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raise
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def test_callable_spec(callable, callable_args, callable_kwargs):
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"""
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Inspect callable and test to see if the given args are suitable for it.
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When an error occurs during the handler's invoking stage there are 2
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erroneous cases:
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1. Too many parameters passed to a function which doesn't define
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one of *args or **kwargs.
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2. Too little parameters are passed to the function.
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There are 3 sources of parameters to a cherrypy handler.
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1. query string parameters are passed as keyword parameters to the handler.
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2. body parameters are also passed as keyword parameters.
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3. when partial matching occurs, the final path atoms are passed as
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positional args.
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Both the query string and path atoms are part of the URI. If they are
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incorrect, then a 404 Not Found should be raised. Conversely the body
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parameters are part of the request; if they are invalid a 400 Bad Request.
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"""
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show_mismatched_params = getattr(
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cherrypy.serving.request, 'show_mismatched_params', False)
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try:
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(args, varargs, varkw, defaults) = inspect.getargspec(callable)
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except TypeError:
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if isinstance(callable, object) and hasattr(callable, '__call__'):
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(args, varargs, varkw, defaults) = inspect.getargspec(callable.__call__)
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else:
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# If it wasn't one of our own types, re-raise
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# the original error
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raise
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if args and args[0] == 'self':
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args = args[1:]
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arg_usage = dict([(arg, 0,) for arg in args])
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vararg_usage = 0
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varkw_usage = 0
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extra_kwargs = set()
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for i, value in enumerate(callable_args):
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try:
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arg_usage[args[i]] += 1
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except IndexError:
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vararg_usage += 1
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for key in callable_kwargs.keys():
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try:
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arg_usage[key] += 1
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except KeyError:
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varkw_usage += 1
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extra_kwargs.add(key)
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# figure out which args have defaults.
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args_with_defaults = args[-len(defaults or []):]
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for i, val in enumerate(defaults or []):
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# Defaults take effect only when the arg hasn't been used yet.
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if arg_usage[args_with_defaults[i]] == 0:
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arg_usage[args_with_defaults[i]] += 1
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missing_args = []
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multiple_args = []
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for key, usage in arg_usage.items():
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if usage == 0:
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missing_args.append(key)
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elif usage > 1:
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multiple_args.append(key)
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if missing_args:
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# In the case where the method allows body arguments
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# there are 3 potential errors:
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# 1. not enough query string parameters -> 404
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# 2. not enough body parameters -> 400
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# 3. not enough path parts (partial matches) -> 404
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#
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# We can't actually tell which case it is,
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# so I'm raising a 404 because that covers 2/3 of the
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# possibilities
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#
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# In the case where the method does not allow body
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# arguments it's definitely a 404.
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message = None
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if show_mismatched_params:
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message="Missing parameters: %s" % ",".join(missing_args)
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raise cherrypy.HTTPError(404, message=message)
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# the extra positional arguments come from the path - 404 Not Found
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if not varargs and vararg_usage > 0:
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raise cherrypy.HTTPError(404)
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body_params = cherrypy.serving.request.body.params or {}
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body_params = set(body_params.keys())
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qs_params = set(callable_kwargs.keys()) - body_params
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if multiple_args:
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if qs_params.intersection(set(multiple_args)):
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# If any of the multiple parameters came from the query string then
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# it's a 404 Not Found
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error = 404
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else:
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# Otherwise it's a 400 Bad Request
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error = 400
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message = None
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if show_mismatched_params:
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message="Multiple values for parameters: "\
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"%s" % ",".join(multiple_args)
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raise cherrypy.HTTPError(error, message=message)
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if not varkw and varkw_usage > 0:
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# If there were extra query string parameters, it's a 404 Not Found
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extra_qs_params = set(qs_params).intersection(extra_kwargs)
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if extra_qs_params:
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message = None
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if show_mismatched_params:
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message="Unexpected query string "\
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"parameters: %s" % ", ".join(extra_qs_params)
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raise cherrypy.HTTPError(404, message=message)
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# If there were any extra body parameters, it's a 400 Not Found
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extra_body_params = set(body_params).intersection(extra_kwargs)
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if extra_body_params:
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message = None
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if show_mismatched_params:
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message="Unexpected body parameters: "\
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"%s" % ", ".join(extra_body_params)
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raise cherrypy.HTTPError(400, message=message)
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try:
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import inspect
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except ImportError:
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test_callable_spec = lambda callable, args, kwargs: None
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class LateParamPageHandler(PageHandler):
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"""When passing cherrypy.request.params to the page handler, we do not
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want to capture that dict too early; we want to give tools like the
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decoding tool a chance to modify the params dict in-between the lookup
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of the handler and the actual calling of the handler. This subclass
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takes that into account, and allows request.params to be 'bound late'
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(it's more complicated than that, but that's the effect).
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"""
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def _get_kwargs(self):
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kwargs = cherrypy.serving.request.params.copy()
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if self._kwargs:
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kwargs.update(self._kwargs)
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return kwargs
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def _set_kwargs(self, kwargs):
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self._kwargs = kwargs
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kwargs = property(_get_kwargs, _set_kwargs,
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doc='page handler kwargs (with '
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'cherrypy.request.params copied in)')
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punctuation_to_underscores = string.maketrans(
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string.punctuation, '_' * len(string.punctuation))
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class Dispatcher(object):
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"""CherryPy Dispatcher which walks a tree of objects to find a handler.
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The tree is rooted at cherrypy.request.app.root, and each hierarchical
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component in the path_info argument is matched to a corresponding nested
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attribute of the root object. Matching handlers must have an 'exposed'
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attribute which evaluates to True. The special method name "index"
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matches a URI which ends in a slash ("/"). The special method name
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"default" may match a portion of the path_info (but only when no longer
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substring of the path_info matches some other object).
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This is the default, built-in dispatcher for CherryPy.
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"""
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dispatch_method_name = '_cp_dispatch'
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"""
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The name of the dispatch method that nodes may optionally implement
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to provide their own dynamic dispatch algorithm.
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"""
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def __init__(self, dispatch_method_name=None,
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translate=punctuation_to_underscores):
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if not isinstance(translate, str) or len(translate) != 256:
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raise ValueError("The translate argument must be a str of len 256.")
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self.translate = translate
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if dispatch_method_name:
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self.dispatch_method_name = dispatch_method_name
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def __call__(self, path_info):
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"""Set handler and config for the current request."""
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request = cherrypy.serving.request
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func, vpath = self.find_handler(path_info)
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if func:
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# Decode any leftover %2F in the virtual_path atoms.
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vpath = [x.replace("%2F", "/") for x in vpath]
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request.handler = LateParamPageHandler(func, *vpath)
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else:
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request.handler = cherrypy.NotFound()
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def find_handler(self, path):
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"""Return the appropriate page handler, plus any virtual path.
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This will return two objects. The first will be a callable,
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which can be used to generate page output. Any parameters from
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the query string or request body will be sent to that callable
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as keyword arguments.
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The callable is found by traversing the application's tree,
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starting from cherrypy.request.app.root, and matching path
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components to successive objects in the tree. For example, the
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URL "/path/to/handler" might return root.path.to.handler.
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The second object returned will be a list of names which are
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'virtual path' components: parts of the URL which are dynamic,
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and were not used when looking up the handler.
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These virtual path components are passed to the handler as
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positional arguments.
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"""
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request = cherrypy.serving.request
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app = request.app
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root = app.root
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dispatch_name = self.dispatch_method_name
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# Get config for the root object/path.
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fullpath = [x for x in path.strip('/').split('/') if x] + ['index']
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fullpath_len = len(fullpath)
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segleft = fullpath_len
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nodeconf = {}
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if hasattr(root, "_cp_config"):
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nodeconf.update(root._cp_config)
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if "/" in app.config:
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nodeconf.update(app.config["/"])
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object_trail = [['root', root, nodeconf, segleft]]
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node = root
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iternames = fullpath[:]
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while iternames:
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name = iternames[0]
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# map to legal Python identifiers (e.g. replace '.' with '_')
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objname = name.translate(self.translate)
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nodeconf = {}
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subnode = getattr(node, objname, None)
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pre_len = len(iternames)
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if subnode is None:
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dispatch = getattr(node, dispatch_name, None)
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if dispatch and hasattr(dispatch, '__call__') and not \
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getattr(dispatch, 'exposed', False) and \
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pre_len > 1:
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#Don't expose the hidden 'index' token to _cp_dispatch
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#We skip this if pre_len == 1 since it makes no sense
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#to call a dispatcher when we have no tokens left.
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index_name = iternames.pop()
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subnode = dispatch(vpath=iternames)
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iternames.append(index_name)
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else:
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#We didn't find a path, but keep processing in case there
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#is a default() handler.
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iternames.pop(0)
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else:
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#We found the path, remove the vpath entry
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iternames.pop(0)
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segleft = len(iternames)
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if segleft > pre_len:
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#No path segment was removed. Raise an error.
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raise cherrypy.CherryPyException(
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"A vpath segment was added. Custom dispatchers may only "
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+ "remove elements. While trying to process "
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+ "{0} in {1}".format(name, fullpath)
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)
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elif segleft == pre_len:
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#Assume that the handler used the current path segment, but
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#did not pop it. This allows things like
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#return getattr(self, vpath[0], None)
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iternames.pop(0)
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segleft -= 1
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node = subnode
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if node is not None:
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# Get _cp_config attached to this node.
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if hasattr(node, "_cp_config"):
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nodeconf.update(node._cp_config)
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# Mix in values from app.config for this path.
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existing_len = fullpath_len - pre_len
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if existing_len != 0:
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curpath = '/' + '/'.join(fullpath[0:existing_len])
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else:
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curpath = ''
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new_segs = fullpath[fullpath_len - pre_len:fullpath_len - segleft]
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for seg in new_segs:
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curpath += '/' + seg
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if curpath in app.config:
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nodeconf.update(app.config[curpath])
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object_trail.append([name, node, nodeconf, segleft])
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def set_conf():
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"""Collapse all object_trail config into cherrypy.request.config."""
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base = cherrypy.config.copy()
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# Note that we merge the config from each node
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# even if that node was None.
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for name, obj, conf, segleft in object_trail:
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base.update(conf)
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if 'tools.staticdir.dir' in conf:
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base['tools.staticdir.section'] = '/' + '/'.join(fullpath[0:fullpath_len - segleft])
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return base
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# Try successive objects (reverse order)
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num_candidates = len(object_trail) - 1
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for i in range(num_candidates, -1, -1):
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name, candidate, nodeconf, segleft = object_trail[i]
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if candidate is None:
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continue
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# Try a "default" method on the current leaf.
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if hasattr(candidate, "default"):
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defhandler = candidate.default
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if getattr(defhandler, 'exposed', False):
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# Insert any extra _cp_config from the default handler.
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conf = getattr(defhandler, "_cp_config", {})
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object_trail.insert(i+1, ["default", defhandler, conf, segleft])
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request.config = set_conf()
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# See http://www.cherrypy.org/ticket/613
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request.is_index = path.endswith("/")
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return defhandler, fullpath[fullpath_len - segleft:-1]
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# Uncomment the next line to restrict positional params to "default".
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# if i < num_candidates - 2: continue
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# Try the current leaf.
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if getattr(candidate, 'exposed', False):
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request.config = set_conf()
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if i == num_candidates:
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# We found the extra ".index". Mark request so tools
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# can redirect if path_info has no trailing slash.
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request.is_index = True
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else:
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# We're not at an 'index' handler. Mark request so tools
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# can redirect if path_info has NO trailing slash.
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# Note that this also includes handlers which take
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# positional parameters (virtual paths).
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request.is_index = False
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return candidate, fullpath[fullpath_len - segleft:-1]
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# We didn't find anything
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request.config = set_conf()
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return None, []
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class MethodDispatcher(Dispatcher):
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"""Additional dispatch based on cherrypy.request.method.upper().
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Methods named GET, POST, etc will be called on an exposed class.
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The method names must be all caps; the appropriate Allow header
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will be output showing all capitalized method names as allowable
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HTTP verbs.
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Note that the containing class must be exposed, not the methods.
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"""
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def __call__(self, path_info):
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"""Set handler and config for the current request."""
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request = cherrypy.serving.request
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resource, vpath = self.find_handler(path_info)
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if resource:
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# Set Allow header
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avail = [m for m in dir(resource) if m.isupper()]
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if "GET" in avail and "HEAD" not in avail:
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avail.append("HEAD")
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avail.sort()
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cherrypy.serving.response.headers['Allow'] = ", ".join(avail)
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# Find the subhandler
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meth = request.method.upper()
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func = getattr(resource, meth, None)
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if func is None and meth == "HEAD":
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func = getattr(resource, "GET", None)
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if func:
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# Grab any _cp_config on the subhandler.
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if hasattr(func, "_cp_config"):
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request.config.update(func._cp_config)
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# Decode any leftover %2F in the virtual_path atoms.
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vpath = [x.replace("%2F", "/") for x in vpath]
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request.handler = LateParamPageHandler(func, *vpath)
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else:
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request.handler = cherrypy.HTTPError(405)
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else:
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request.handler = cherrypy.NotFound()
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class RoutesDispatcher(object):
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"""A Routes based dispatcher for CherryPy."""
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def __init__(self, full_result=False):
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"""
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Routes dispatcher
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Set full_result to True if you wish the controller
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and the action to be passed on to the page handler
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parameters. By default they won't be.
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"""
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import routes
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self.full_result = full_result
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self.controllers = {}
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self.mapper = routes.Mapper()
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self.mapper.controller_scan = self.controllers.keys
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def connect(self, name, route, controller, **kwargs):
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self.controllers[name] = controller
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self.mapper.connect(name, route, controller=name, **kwargs)
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def redirect(self, url):
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raise cherrypy.HTTPRedirect(url)
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def __call__(self, path_info):
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"""Set handler and config for the current request."""
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func = self.find_handler(path_info)
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if func:
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cherrypy.serving.request.handler = LateParamPageHandler(func)
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else:
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cherrypy.serving.request.handler = cherrypy.NotFound()
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def find_handler(self, path_info):
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"""Find the right page handler, and set request.config."""
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import routes
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request = cherrypy.serving.request
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config = routes.request_config()
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config.mapper = self.mapper
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if hasattr(request, 'wsgi_environ'):
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config.environ = request.wsgi_environ
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config.host = request.headers.get('Host', None)
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config.protocol = request.scheme
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config.redirect = self.redirect
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result = self.mapper.match(path_info)
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config.mapper_dict = result
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params = {}
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if result:
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params = result.copy()
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if not self.full_result:
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params.pop('controller', None)
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params.pop('action', None)
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request.params.update(params)
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# Get config for the root object/path.
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request.config = base = cherrypy.config.copy()
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curpath = ""
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def merge(nodeconf):
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if 'tools.staticdir.dir' in nodeconf:
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nodeconf['tools.staticdir.section'] = curpath or "/"
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base.update(nodeconf)
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app = request.app
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root = app.root
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if hasattr(root, "_cp_config"):
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merge(root._cp_config)
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if "/" in app.config:
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merge(app.config["/"])
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# Mix in values from app.config.
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atoms = [x for x in path_info.split("/") if x]
|
|
if atoms:
|
|
last = atoms.pop()
|
|
else:
|
|
last = None
|
|
for atom in atoms:
|
|
curpath = "/".join((curpath, atom))
|
|
if curpath in app.config:
|
|
merge(app.config[curpath])
|
|
|
|
handler = None
|
|
if result:
|
|
controller = result.get('controller')
|
|
controller = self.controllers.get(controller, controller)
|
|
if controller:
|
|
if isinstance(controller, (type, types.ClassType)):
|
|
controller = controller()
|
|
# Get config from the controller.
|
|
if hasattr(controller, "_cp_config"):
|
|
merge(controller._cp_config)
|
|
|
|
action = result.get('action')
|
|
if action is not None:
|
|
handler = getattr(controller, action, None)
|
|
# Get config from the handler
|
|
if hasattr(handler, "_cp_config"):
|
|
merge(handler._cp_config)
|
|
else:
|
|
handler = controller
|
|
|
|
# Do the last path atom here so it can
|
|
# override the controller's _cp_config.
|
|
if last:
|
|
curpath = "/".join((curpath, last))
|
|
if curpath in app.config:
|
|
merge(app.config[curpath])
|
|
|
|
return handler
|
|
|
|
|
|
def XMLRPCDispatcher(next_dispatcher=Dispatcher()):
|
|
from cherrypy.lib import xmlrpc
|
|
def xmlrpc_dispatch(path_info):
|
|
path_info = xmlrpc.patched_path(path_info)
|
|
return next_dispatcher(path_info)
|
|
return xmlrpc_dispatch
|
|
|
|
|
|
def VirtualHost(next_dispatcher=Dispatcher(), use_x_forwarded_host=True, **domains):
|
|
"""
|
|
Select a different handler based on the Host header.
|
|
|
|
This can be useful when running multiple sites within one CP server.
|
|
It allows several domains to point to different parts of a single
|
|
website structure. For example::
|
|
|
|
http://www.domain.example -> root
|
|
http://www.domain2.example -> root/domain2/
|
|
http://www.domain2.example:443 -> root/secure
|
|
|
|
can be accomplished via the following config::
|
|
|
|
[/]
|
|
request.dispatch = cherrypy.dispatch.VirtualHost(
|
|
**{'www.domain2.example': '/domain2',
|
|
'www.domain2.example:443': '/secure',
|
|
})
|
|
|
|
next_dispatcher
|
|
The next dispatcher object in the dispatch chain.
|
|
The VirtualHost dispatcher adds a prefix to the URL and calls
|
|
another dispatcher. Defaults to cherrypy.dispatch.Dispatcher().
|
|
|
|
use_x_forwarded_host
|
|
If True (the default), any "X-Forwarded-Host"
|
|
request header will be used instead of the "Host" header. This
|
|
is commonly added by HTTP servers (such as Apache) when proxying.
|
|
|
|
``**domains``
|
|
A dict of {host header value: virtual prefix} pairs.
|
|
The incoming "Host" request header is looked up in this dict,
|
|
and, if a match is found, the corresponding "virtual prefix"
|
|
value will be prepended to the URL path before calling the
|
|
next dispatcher. Note that you often need separate entries
|
|
for "example.com" and "www.example.com". In addition, "Host"
|
|
headers may contain the port number.
|
|
"""
|
|
from cherrypy.lib import httputil
|
|
def vhost_dispatch(path_info):
|
|
request = cherrypy.serving.request
|
|
header = request.headers.get
|
|
|
|
domain = header('Host', '')
|
|
if use_x_forwarded_host:
|
|
domain = header("X-Forwarded-Host", domain)
|
|
|
|
prefix = domains.get(domain, "")
|
|
if prefix:
|
|
path_info = httputil.urljoin(prefix, path_info)
|
|
|
|
result = next_dispatcher(path_info)
|
|
|
|
# Touch up staticdir config. See http://www.cherrypy.org/ticket/614.
|
|
section = request.config.get('tools.staticdir.section')
|
|
if section:
|
|
section = section[len(prefix):]
|
|
request.config['tools.staticdir.section'] = section
|
|
|
|
return result
|
|
return vhost_dispatch
|
|
|