/usr/lib/python2.7/dist-packages/crank/restdispatcher.py is in python-crank 0.7.2-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 | """
This module contains the RestDispatcher implementation
Rest controller provides a RESTful dispatch mechanism, and
combines controller decoration for TG-Controller behavior.
"""
from inspect import ismethod
from webob.exc import HTTPMethodNotAllowed
from crank.util import get_argspec, method_matches_args
from crank.objectdispatcher import ObjectDispatcher
class RestDispatcher(ObjectDispatcher):
"""Defines a restful interface for a set of HTTP verbs.
Please see RestController for a rundown of the controller
methods used.
"""
def _find_first_exposed(self, controller, methods):
for method in methods:
if self._is_exposed(controller, method):
return getattr(controller, method)
def _handle_put_or_post(self, http_method, state, remainder):
current_controller = state.controller
if remainder:
current_path = remainder[0]
if self._is_exposed(current_controller, current_path):
state.add_method(getattr(current_controller, current_path), remainder[1:])
return state
if self._is_controller(current_controller, current_path):
current_controller = getattr(current_controller, current_path)
return self._dispatch_controller(current_path, current_controller, state, remainder[1:])
method = self._find_first_exposed(current_controller, [http_method])
if method and method_matches_args(method, state.params, remainder, self._use_lax_params):
state.add_method(method, remainder)
return state
return self._dispatch_first_found_default_or_lookup(state, remainder)
def _handle_delete(self, http_method, state, remainder):
current_controller = state.controller
method = self._find_first_exposed(current_controller, ('post_delete', 'delete'))
if method and method_matches_args(method, state.params, remainder, self._use_lax_params):
state.add_method(method, remainder)
return state
#you may not send a delete request to a non-delete function
if remainder and self._is_exposed(current_controller, remainder[0]):
raise HTTPMethodNotAllowed
# there might be a sub-controller with a delete method, let's go see
if remainder:
sub_controller = getattr(current_controller, remainder[0], None)
if sub_controller:
remainder = remainder[1:]
state.current_controller = sub_controller
state.path = remainder
r = self._dispatch_controller(remainder[0], sub_controller, state, remainder)
if r:
return r
return self._dispatch_first_found_default_or_lookup(state, remainder)
def _check_for_sub_controllers(self, state, remainder):
current_controller = state.controller
method = None
for find in ('get_one', 'get'):
if hasattr(current_controller, find):
method = find
break
if method is None:
return
fixed_args, var_args, kws, kw_args = get_argspec(getattr(current_controller, method))
fixed_arg_length = len(fixed_args)
if var_args:
for i, item in enumerate(remainder):
item = state.path_translator(item)
if hasattr(current_controller, item) and self._is_controller(current_controller, item):
current_controller = getattr(current_controller, item)
state.add_routing_args(item, remainder[:i], fixed_args, var_args)
return self._dispatch_controller(item, current_controller, state, remainder[i+1:])
elif fixed_arg_length< len(remainder) and hasattr(current_controller, remainder[fixed_arg_length]):
item = state.path_translator(remainder[fixed_arg_length])
if hasattr(current_controller, item):
if self._is_controller(current_controller, item):
state.add_routing_args(item, remainder, fixed_args, var_args)
return self._dispatch_controller(item, getattr(current_controller, item),
state, remainder[fixed_arg_length+1:])
def _handle_delete_edit_or_new(self, state, remainder):
method_name = remainder[-1]
if method_name not in ('new', 'edit', 'delete'):
return
if method_name == 'delete':
method_name = 'get_delete'
current_controller = state.controller
if self._is_exposed(current_controller, method_name):
method = getattr(current_controller, method_name)
new_remainder = remainder[:-1]
if method and method_matches_args(method, state.params, new_remainder, self._use_lax_params):
state.add_method(method, new_remainder)
return state
def _handle_custom_get(self, state, remainder):
controller = state.controller
method_name = remainder[-1]
current_controller = state.controller
get_method = self._find_first_exposed(current_controller, ('get_%s' % method_name, method_name))
if get_method:
new_remainder = remainder[:-1]
if method_matches_args(get_method, state.params, new_remainder, self._use_lax_params):
state.add_method(get_method, new_remainder)
return state
def _handle_custom_method(self, method, state, remainder):
current_controller = state.controller
method_name = method
http_method = state.request.method
method = self._find_first_exposed(current_controller, ('%s_%s' %(http_method, method_name), method_name, 'post_%s' %method_name))
if method and method_matches_args(method, state.params, remainder, self._use_lax_params):
state.add_method(method, remainder)
return state
# there might be a sub-controller with a custom method, let's go see
if remainder:
sub_controller = getattr(current_controller, remainder[0], None)
if sub_controller:
current = remainder[0]
remainder = remainder[1:]
state.current_controller = sub_controller
state.path = remainder
r = self._dispatch_controller(current, sub_controller, state, remainder)
if r:
return r
return self._dispatch_first_found_default_or_lookup(state, remainder)
def _handle_get(self, method, state, remainder):
current_controller = state.controller
if not remainder:
method = self._find_first_exposed(current_controller, ('get_all', 'get'))
if method:
state.add_method(method, remainder)
return state
if self._is_exposed(current_controller, 'get_one'):
method = current_controller.get_one
if method and method_matches_args(method, state.params, remainder, self._use_lax_params):
state.add_method(method, remainder)
return state
return self._dispatch_first_found_default_or_lookup(state, remainder)
#test for "delete", "edit" or "new"
r = self._handle_delete_edit_or_new(state, remainder)
if r is not None:
return r
#test for custom REST-like attribute
r = self._handle_custom_get(state, remainder)
if r is not None:
return r
current_path = state.path_translator(remainder[0])
if self._is_exposed(current_controller, current_path):
state.add_method(getattr(current_controller, current_path), remainder[1:])
return state
if self._is_controller(current_controller, current_path):
current_controller = getattr(current_controller, current_path)
return self._dispatch_controller(current_path, current_controller, state, remainder[1:])
method = self._find_first_exposed(current_controller, ('get_one', 'get'))
if method and method_matches_args(method, state.params, remainder, self._use_lax_params):
state.add_method(method, remainder)
return state
return self._dispatch_first_found_default_or_lookup(state, remainder)
_handler_lookup = {
'put':_handle_put_or_post,
'post':_handle_put_or_post,
'delete':_handle_delete,
'get':_handle_get,
}
def _is_controller(self, controller, name):
"""
Override this function to define how an object is determined to be a
controller.
"""
method = getattr(controller, name, None)
if method is not None:
return not ismethod(method)
def _dispatch(self, state, remainder=None):
"""
This method defines how the object dispatch mechanism works, including
checking for security along the way.
"""
if state.dispatcher is None:
state.dispatcher = self
state.add_controller('/', self)
if remainder is None:
remainder = state.path
self._enter_controller(state, remainder)
#log.debug('Entering dispatch for remainder: %s in controller %s'%(remainder, self))
if not hasattr(state, 'http_method'):
method = state.request.method.lower()
params = state.params
#conventional hack for handling methods which are not supported by most browsers
request_method = params.get('_method', None)
if request_method:
request_method = request_method.lower()
#make certain that DELETE and PUT requests are not sent with GET
if method == 'get' and request_method == 'put':
raise HTTPMethodNotAllowed
if method == 'get' and request_method == 'delete':
raise HTTPMethodNotAllowed
method = request_method
del state.params['_method']
state.http_method = method
r = self._check_for_sub_controllers(state, remainder)
if r is not None:
return r
if state.http_method in self._handler_lookup.keys():
r = self._handler_lookup[state.http_method](self, state.http_method, state, remainder)
else:
r = self._handle_custom_method(state.http_method, state, remainder)
return r
|