Issue 2711 - Refactored ChainedConfigParser, allowing manipulation of list items

chainedconfigparser.py

 # coding: utf-8
 
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import os
 import io
 import ConfigParser
 from StringIO import StringIO
@@ skipping 26 matching lines @@
     whitespace-separated lists given by an inherited option:
 
     [section]
     opt1 += foo
     opt2 -= bar
 
     The value of the inherit option has to be a relative path with forward
     slashes as delimiters. Up to 5 configuration files can be chained this way,
     longer chains are disallowed to deal with circular references.
 
-    As opposed to ChainedConfigParser, files are decoded as UTF-8 while reading.

[Wladimir Palant, 2015/07/07 14:53:17]

Did you mean SafeConfigParser?

[Sebastian Noack, 2015/07/07 15:20:43]

Yes, corrected.

-    Also, ChainedConfigParser data is read-only and the options are case-sensitive.

[Wladimir Palant, 2015/07/07 14:53:17]

Nit: "case-sensitive by default" (it's configurable now). Also, please break at
80 characters.

[Sebastian Noack, 2015/07/07 15:20:43]

Not really. There were some code assumptions, relying on optionxform beeing
noop. But while thinking about it, it makes sense to remove these assumptions
and configure optionxform externally rather than documenting the non-standard
behavior here. Did that.
Done.

-    An additional option_source(section, option) method is provided to get the
-    path of the configuration file defining this option (for relative paths).
-    Items returned by the items() function also have a source attribute serving
-    the same purpose.
+    As opposed to SafeConfigParser, files are decoded as UTF-8 while
+    reading. Also, ChainedConfigParser data is read-only. An additional
+    option_source(section, option) method is provided to get the path
+    of the configuration file defining this option (for relative paths).
+    Items returned by the items() function also have a source attribute
+    serving the same purpose.
   '''
 
   def __init__(self):
     ConfigParser.SafeConfigParser.__init__(self)
     self._origin = {}
 
   def _make_parser(self, filename):
     parser = ConfigParser.SafeConfigParser()
-    parser.optionxform = self.optionxform
+    parser.optionxform = lambda option: option
 
     with io.open(filename, encoding='utf-8') as file:
       parser.readfp(file, filename)
 
     return parser
 
   def _get_parser_chain(self, parser, filename):
     parsers = []
 
     while True:
@@ skipping 40 matching lines @@
             # add_section() hardcodes 'default' and raises a ValueError if
             # you try to add a section called like that (case insensitive).
             # This bug has been fixed in Python 3.
             ConfigParser.SafeConfigParser.readfp(self, StringIO('[%s]' % section))
 
         for option, value in parser.items(section):
           is_diff, option, value = self._apply_diff(section, option, value)
           ConfigParser.SafeConfigParser.set(self, section, option, value)
 
           if not is_diff:
-            self._origin[(section, option)] = filename
+            self._origin[(section, self.optionxform(option))] = filename
 
   def read(self, filenames):
     if isinstance(filenames, basestring):
       filenames = [filenames]
 
     read_ok = []
     for filename in filenames:
       try:
         parser = self._make_parser(filename)
       except IOError:
         continue
       self._process_parsers(self._get_parser_chain(parser, filename))
       read_ok.append(filename)
 
     return read_ok
 
   def items(self, section, *args, **kwargs):
     items = []
     for option, value in ConfigParser.SafeConfigParser.items(self, section, *args, **kwargs):
-      items.append(Item(option, value, self._origin[(section, option)]))
+      items.append(Item(
+        option, value,
+        self._origin[(section, self.optionxform(option))]
+      ))
     return items
 
   def option_source(self, section, option):
+    option = self.optionxform(option)
     try:
       return self._origin[(section, option)]
     except KeyError:
       if not self.has_section(section):
         raise ConfigParser.NoSectionError(section)
       raise ConfigParser.NoOptionError(option, section)
-
-  def optionxform(self, option):
-    return option
 
   def readfp(self, fp, filename=None):
     raise NotImplementedError
 
   def set(self, section, option, value=None):
     raise NotImplementedError
 
   def add_section(self, section):
     raise NotImplementedError
 
   def remove_option(self, section, option):
     raise NotImplementedError
 
   def remove_section(self, section):
     raise NotImplementedError