Adding upstream version 1.0.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

feedgen/util.py

@@ -0,0 +1,96 @@
+# -*- coding: utf-8 -*-
+'''
+    feedgen.util
+    ~~~~~~~~~~~~
+
+    This file contains helper functions for the feed generator module.
+
+    :copyright: 2013, Lars Kiesow <lkiesow@uos.de>
+    :license: FreeBSD and LGPL, see license.* for more details.
+'''
+import locale
+import sys
+import lxml  # nosec - we configure a safe parser below
+
+# Configure a safe parser which does not allow XML entity expansion
+parser = lxml.etree.XMLParser(
+        attribute_defaults=False,
+        dtd_validation=False,
+        load_dtd=False,
+        no_network=True,
+        recover=False,
+        remove_pis=True,
+        resolve_entities=False,
+        huge_tree=False)
+
+
+def xml_fromstring(xmlstring):
+    return lxml.etree.fromstring(xmlstring, parser)  # nosec - safe parser
+
+
+def xml_elem(name, parent=None, **kwargs):
+    if parent is not None:
+        return lxml.etree.SubElement(parent, name, **kwargs)
+    return lxml.etree.Element(name, **kwargs)
+
+
+def ensure_format(val, allowed, required, allowed_values=None, defaults=None):
+    '''Takes a dictionary or a list of dictionaries and check if all keys are
+    in the set of allowed keys, if all required keys are present and if the
+    values of a specific key are ok.
+
+    :param val:            Dictionaries to check.
+    :param allowed:        Set of allowed keys.
+    :param required:       Set of required keys.
+    :param allowed_values: Dictionary with keys and sets of their allowed
+                           values.
+    :param defaults:       Dictionary with default values.
+    :returns:              List of checked dictionaries.
+    '''
+    if not val:
+        return []
+    if allowed_values is None:
+        allowed_values = {}
+    if defaults is None:
+        defaults = {}
+    # Make sure that we have a list of dicts. Even if there is only one.
+    if not isinstance(val, list):
+        val = [val]
+    for elem in val:
+        if not isinstance(elem, dict):
+            raise ValueError('Invalid data (value is no dictionary)')
+        # Set default values
+
+        version = sys.version_info[0]
+
+        if version == 2:
+            items = defaults.iteritems()
+        else:
+            items = defaults.items()
+
+        for k, v in items:
+            elem[k] = elem.get(k, v)
+        if not set(elem.keys()) <= allowed:
+            raise ValueError('Data contains invalid keys')
+        if not set(elem.keys()) >= required:
+            raise ValueError('Data contains not all required keys')
+
+        if version == 2:
+            values = allowed_values.iteritems()
+        else:
+            values = allowed_values.items()
+
+        for k, v in values:
+            if elem.get(k) and not elem[k] in v:
+                raise ValueError('Invalid value for %s' % k)
+    return val
+
+
+def formatRFC2822(date):
+    '''Make sure the locale setting do not interfere with the time format.
+    '''
+    old = locale.setlocale(locale.LC_ALL)
+    locale.setlocale(locale.LC_ALL, 'C')
+    date = date.strftime('%a, %d %b %Y %H:%M:%S %z')
+    locale.setlocale(locale.LC_ALL, old)
+    return date