# $Id: misc.py 6314 2010-04-26 10:04:17Z milde $ # Author: David Goodger # 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::
...
... into this::
...
... """ 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.', source=node.source, 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.', source=node.source, 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)