1 files changed, 145 insertions, 0 deletions
diff --git a/docutils/transforms/misc.py b/docutils/transforms/misc.py
new file mode 100644
index 000000000..9567055f9
--- /dev/null
+++ b/docutils/transforms/misc.py
@@ -0,0 +1,145 @@
+# Author: David Goodger
+# Contact: goodger@users.sourceforge.net
+# Revision: $Revision$
+# Date: $Date$
+# Copyright: This module has been placed in the public domain.
+
+"""
+Miscellaneous transforms.
+"""
+
+__docformat__ = 'reStructuredText'
+
+from docutils import nodes
+from docutils.transforms import Transform, TransformError
+
+
+class CallBack(Transform):
+
+    """
+    Inserts a callback into a document.  The callback is called when the
+    transform is applied, which is determined by its priority.
+
+    For use with `nodes.pending` elements.  Requires a ``details['callback']``
+    entry, a bound method or function which takes one parameter: the pending
+    node.  Other data can be stored in the ``details`` attribute or in the
+    object hosting the callback method.
+    """
+
+    default_priority = 990
+
+    def apply(self):
+        pending = self.startnode
+        pending.details['callback'](pending)
+        pending.parent.remove(pending)
+
+
+class ClassAttribute(Transform):
+
+    """
+    Move the "class" attribute specified in the "pending" node into the
+    immediately following non-comment element.
+    """
+
+    default_priority = 210
+
+    def apply(self):
+        pending = self.startnode
+        parent = pending.parent
+        child = pending
+        while parent:
+            # Check for appropriate following siblings:
+            for index in range(parent.index(child) + 1, len(parent)):
+                element = parent[index]
+                if (isinstance(element, nodes.Invisible) or
+                    isinstance(element, nodes.system_message)):
+                    continue
+                element['classes'] += pending.details['class']
+                pending.parent.remove(pending)
+                return
+            else:
+                # At end of section or container; apply to sibling
+                child = parent
+                parent = parent.parent
+        error = self.document.reporter.error(
+            'No suitable element following "%s" directive'
+            % pending.details['directive'],
+            nodes.literal_block(pending.rawsource, pending.rawsource),
+            line=pending.line)
+        pending.replace_self(error)
+
+
+class Transitions(Transform):
+
+    """
+    Move transitions at the end of sections up the tree.  Complain
+    on transitions after a title, at the beginning or end of the
+    document, and after another transition.
+
+    For example, transform this::
+
+        <section>
+            ...
+            <transition>
+        <section>
+            ...
+
+    into this::
+
+        <section>
+            ...
+        <transition>
+        <section>
+            ...
+    """
+
+    default_priority = 830
+
+    def apply(self):
+        for node in self.document.traverse(nodes.transition):
+            self.visit_transition(node)
+
+    def visit_transition(self, node):
+        index = node.parent.index(node)
+        error = None
+        if (index == 0 or
+            isinstance(node.parent[0], nodes.title) and
+            (index == 1 or
+             isinstance(node.parent[1], nodes.subtitle) and
+             index == 2)):
+            assert (isinstance(node.parent, nodes.document) or
+                    isinstance(node.parent, nodes.section))
+            error = self.document.reporter.error(
+                'Document or section may not begin with a transition.',
+                line=node.line)
+        elif isinstance(node.parent[index - 1], nodes.transition):
+            error = self.document.reporter.error(
+                'At least one body element must separate transitions; '
+                'adjacent transitions are not allowed.', line=node.line)
+        if error:
+            # Insert before node and update index.
+            node.parent.insert(index, error)
+            index += 1
+        assert index < len(node.parent)
+        if index != len(node.parent) - 1:
+            # No need to move the node.
+            return
+        # Node behind which the transition is to be moved.
+        sibling = node
+        # While sibling is the last node of its parent.
+        while index == len(sibling.parent) - 1:
+            sibling = sibling.parent
+            # If sibling is the whole document (i.e. it has no parent).
+            if sibling.parent is None:
+                # Transition at the end of document.  Do not move the
+                # transition up, and place an error behind.
+                error = self.document.reporter.error(
+                    'Document may not end with a transition.',
+                    line=node.line)
+                node.parent.insert(node.parent.index(node) + 1, error)
+                return
+            index = sibling.parent.index(sibling)
+        # Remove the original transition node.
+        node.parent.remove(node)
+        # Insert the transition after the sibling.
+        sibling.parent.insert(index + 1, node)