Added getSingleIndexedParamValue() that retrieves an index into a list of
values from the named query parameter, and then indexes into the supplied list
of values to return the corresponding value from the list. Used to convert
numeric index query parameters passed by POST to the GET redirect target, so
that the GET code can display messages, etc. (without passing the message
itself as a query argument and having to escape it or have silly people pass
in their own...).
--- a/app/soc/views/helpers/template_helpers.py Fri Sep 19 04:28:17 2008 +0000
+++ b/app/soc/views/helpers/template_helpers.py Fri Sep 19 04:50:42 2008 +0000
@@ -57,12 +57,78 @@
return sibling_templates + default_template
+
def unescape(html):
- "Returns the given HTML with ampersands, quotes and carets decoded"
-
+ """Returns the given HTML with ampersands, quotes and carets decoded.
+ """
if not isinstance(html, basestring):
html = str(html)
html.replace('&', '&').replace('<', '<')
html.replace('>', '>').replace('"', '"').replace(''',"'")
return html
+
+
+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