Added ``--strip-elements-with-class`` and ``--strip-class`` options (``strip_elements_with_classes`` and ``strip_classes`` settings) and ``StripClassesAndElements`` transform.

git-svn-id: http://svn.code.sf.net/p/docutils/code/trunk/docutils@4913 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

6 files changed, 87 insertions, 6 deletions

diff --git a/HISTORY.txt b/HISTORY.txt
index 8490a6db0..db5645254 100644
--- a/HISTORY.txt
+++ b/HISTORY.txt
@@ -30,6 +30,9 @@ Changes Since 0.4
   - Paths of applied configuration files are now recorded in the
     runtime setting ``_config_files`` (accessible via
     ``--dump-settings``).
+  - Added ``--strip-elements-with-class`` and ``--strip-class``
+    options (``strip_elements_with_classes`` and ``strip_classes``
+    settings).
 
 * docutils/io.py:
 
@@ -68,7 +71,12 @@ Changes Since 0.4
     object-oriented directive interface.  Errors are now (mostly)
     thrown using the new ``DirectiveError`` class.
 
-* docutils/transforms/writer_aux/:
+* docutils/transforms/universal.py:
+
+  - Added ``StripClasses`` transform to remove from the document tree
+    all elements with classes in ``settings.strip_classes``.
+
+* docutils/transforms/writer_aux.py:
 
   - Added ``Admonitions`` transform to transform specific admonitions
     (like ``note``, ``warning``, etc.) into generic admonitions with a
diff --git a/docs/ref/transforms.txt b/docs/ref/transforms.txt
index 6ce9bae8f..ad330e23f 100644
--- a/docs/ref/transforms.txt
+++ b/docs/ref/transforms.txt
@@ -65,6 +65,8 @@ parts.Contents                  "contents" (d/p),             720
 
 universal.StripComments         Reader (r)                    740
 
+universal.StripClasses          Writer (w)                    750
+
 peps.PEPZero                    peps.Headers (t/p)            760
 
 components.Filter               "meta" (d/p)                  780
diff --git a/docs/user/config.txt b/docs/user/config.txt
index d67e4c95a..2dc134be1 100644
--- a/docs/user/config.txt
+++ b/docs/user/config.txt
@@ -400,12 +400,24 @@ _`strict_visitor`
     Default: disabled (None).  Option: ``--strict-visitor`` (hidden,
     for development use only).
 
+_`strip_classes`
+    List of "classes" attribute values to remove from all elements in
+    the document tree.
+
+    Default: disabled (None).  Option: ``--strip-class``.
+
 _`strip_comments`
     Enable the removal of comment elements from the document tree.
 
     Default: disabled (None).  Options: ``--strip-comment``,
     ``--leave-comments``.
 
+_`strip_elements_with_classes`
+    List of "classes" attribute values; matching elements to be
+    removed from the document tree.
+
+    Default: disabled (None).  Option: ``--strip-element-with-class``.
+
 _`title`
     The document title as metadata, which does not become part of the
     document body.  It overrides a document-supplied title.  For
diff --git a/docutils/frontend.py b/docutils/frontend.py
index 1e446fc6a..034e30769 100644
--- a/docutils/frontend.py
+++ b/docutils/frontend.py
@@ -34,6 +34,8 @@ import warnings
 import ConfigParser as CP
 import codecs
 import docutils
+import docutils.utils
+import docutils.nodes
 try:
     import optparse
     from optparse import SUPPRESS_HELP
@@ -161,13 +163,26 @@ def validate_url_trailing_slash(
     else:
         return value + '/'
 
-def validate_dependency_file(
-    setting, value, option_parser, config_parser=None, config_section=None):
+def validate_dependency_file(setting, value, option_parser,
+                             config_parser=None, config_section=None):
     try:
         return docutils.utils.DependencyList(value)
     except IOError:
         return docutils.utils.DependencyList(None)
 
+def validate_strip_class(setting, value, option_parser,
+                         config_parser=None, config_section=None):
+    if config_parser:                   # validate all values
+        class_values = value
+    else:                               # just validate the latest value
+        class_values = [value[-1]]
+    for class_value in class_values:
+        normalized = docutils.nodes.make_id(class_value)
+        if class_value != normalized:
+            raise ValueError('invalid class value %r (perhaps %r?)'
+                             % (class_value, normalized))
+    return value
+
 def make_paths_absolute(pathdict, keys, base_path=None):
     """
     Interpret filesystem path settings relative to the `base_path` given.
@@ -343,6 +358,16 @@ class OptionParser(optparse.OptionParser, docutils.SettingsSpec):
          ('Leave comment elements in the document tree. (default)',
           ['--leave-comments'],
           {'action': 'store_false', 'dest': 'strip_comments'}),
+         ('Remove all elements with classes="<class>" from the document tree. '
+          '(Multiple-use option.)',
+          ['--strip-elements-with-class'],
+          {'action': 'append', 'dest': 'strip_elements_with_classes',
+           'metavar': '<class>', 'validator': validate_strip_class}),
+         ('Remove all classes="<class>" attributes from elements in the '
+          'document tree. (Multiple-use option.)',
+          ['--strip-class'],
+          {'action': 'append', 'dest': 'strip_classes',
+           'metavar': '<class>', 'validator': validate_strip_class}),
          ('Report system messages at or higher than <level>: "info" or "1", '
           '"warning"/"2" (default), "error"/"3", "severe"/"4", "none"/"5"',
           ['--report', '-r'], {'choices': threshold_choices, 'default': 2,
diff --git a/docutils/transforms/universal.py b/docutils/transforms/universal.py
index a666f99ee..83bd48f84 100644
--- a/docutils/transforms/universal.py
+++ b/docutils/transforms/universal.py
@@ -86,11 +86,11 @@ class ExposeInternals(Transform):
     """
 
     default_priority = 840
-    
+
     def not_Text(self, node):
         return not isinstance(node, nodes.Text)
 
-    def apply(self): 
+    def apply(self):
         if self.document.settings.expose_internals:
             for node in self.document.traverse(self.not_Text):
                 for att in self.document.settings.expose_internals:
@@ -167,3 +167,37 @@ class StripComments(Transform):
         if self.document.settings.strip_comments:
             for node in self.document.traverse(nodes.comment):
                 node.parent.remove(node)
+
+
+class StripClassesAndElements(Transform):
+
+    """
+    Remove from the document tree all elements with classes in
+    `self.document.settings.strip_elements_with_classes` and all "classes"
+    attribute values in `self.document.settings.strip_classes`.
+    """
+
+    default_priority = 750
+
+    def apply(self):
+        if not (self.document.settings.strip_elements_with_classes
+                or self.document.settings.strip_classes):
+            return
+        # prepare dicts for lookup (not sets, for Python 2.2 compatibility):
+        self.strip_elements = dict(
+            [(key, None)
+             for key in (self.document.settings.strip_elements_with_classes
+                         or [])])
+        self.strip_classes = dict(
+            [(key, None) for key in (self.document.settings.strip_classes
+                                     or [])])
+        for node in self.document.traverse(self.check_classes):
+            node.parent.remove(node)
+
+    def check_classes(self, node):
+        if isinstance(node, nodes.Element):
+            for class_value in node['classes'][:]:
+                if class_value in self.strip_classes:
+                    node['classes'].remove(class_value)
+                if class_value in self.strip_elements:
+                    return 1
diff --git a/docutils/writers/__init__.py b/docutils/writers/__init__.py
index 9d5326616..39e1ecd5b 100644
--- a/docutils/writers/__init__.py
+++ b/docutils/writers/__init__.py
@@ -34,7 +34,7 @@ class Writer(Component):
         return Component.get_transforms(self) + [
             universal.Messages,
             universal.FilterMessages,
-            ]
+            universal.StripClassesAndElements,]
 
     document = None
     """The document to write (Docutils doctree); set by `write`."""