--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/views/helpers/request_helpers.py Tue Sep 23 23:20:23 2008 +0000
@@ -0,0 +1,87 @@
+#!/usr/bin/python2.5
+#
+# Copyright 2008 the Melange authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Helpers for manipulating HTTP requests.
+"""
+
+__authors__ = [
+ '"Todd Larsen" <tlarsen@google.com>',
+ ]
+
+
+def getSingleIndexedParamValue(request, param_name, values=()):
+ """Returns a value indexed by a query parameter in the HTTP request.
+
+ Args:
+ request: the Django HTTP request object
+ param_name: name of the query parameter in the HTTP request
+ values: list (or tuple) of ordered values; one of which is
+ retrieved by the index value of the param_name argument in
+ the HTTP request
+
+ Returns:
+ None if the query parameter was not present, was not an integer, or
+ was an integer that is not a valid [0..len(values)-1] index into
+ the values list.
+ Otherwise, returns values[int(param_name value)]
+ """
+ value_idx = request.GET.get(param_name)
+
+ if isinstance(value_idx, (tuple, list)):
+ # keep only the first argument if multiple are present
+ value_idx = value_idx[0]
+
+ try:
+ # GET parameter 'param_name' should be an integer value index
+ value_idx = int(value_idx)
+ except:
+ # ignore bogus or missing parameter values, so return None (no message)
+ return None
+
+ if value_idx < 0:
+ # value index out of range, so return None (no value)
+ return None
+
+ if value_idx >= len(values):
+ # value index out of range, so return None (no value)
+ return None
+
+ # return value associated with valid value index
+ return values[value_idx]
+
+
+def getSingleIndexedParamValueIfMissing(value, request, param_name,
+ values=()):
+ """Returns missing value indexed by a query parameter in the HTTP request.
+
+ Args:
+ value: an existing value, or a "False" value such as None
+ request, param_name, values: see getSingleIndexParamValue()
+
+ Returns:
+ value, if value is "non-False"
+ Otherwise, returns getSingleIndexedParamValue() result.
+ """
+ if value:
+ # value already present, so return it
+ return value
+
+ return getSingleIndexedParamValue(request, param_name, values=values)
+
+
+# TODO(tlarsen): write getMultipleIndexParamValues() that returns a
+# list of values if present, omitting those values that are
+# out of range