docutils.nodes.NodeVisitor

class documentation

class NodeVisitor(object):

Known subclasses: docutils.nodes.GenericNodeVisitor, docutils.nodes.SparseNodeVisitor, docutils.writers._html_base.HTMLTranslator, docutils.writers.latex2e.LaTeXTranslator, docutils.writers.manpage.Translator

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"Visitor" pattern [GoF95] abstract superclass implementation for document tree traversals.

Each node class has corresponding methods, doing nothing by default; override individual methods for specific and useful behaviour. The dispatch_visit() method is called by Node.walk() upon entering a node. Node.walkabout() also calls the dispatch_departure() method before exiting a node.

The dispatch methods call "visit_ + node class name" or "depart_ + node class name", resp.

This is a base class for visitors whose visit_... & depart_... methods must be implemented for all compulsory node types encountered (such as for docutils.writers.Writer subclasses). Unimplemented methods will raise exceptions (except for optional nodes).

For sparse traversals, where only certain node types are of interest, use subclass SparseNodeVisitor instead. When (mostly or entirely) uniform processing is desired, subclass GenericNodeVisitor.

[GoF95]Gamma, Helm, Johnson, Vlissides. Design Patterns: Elements of Reusable Object-Oriented Software. Addison-Wesley, Reading, MA, USA, 1995.
Method __init__ Undocumented
Method dispatch​_departure Call self."depart_ + node class name" with node as parameter. If the depart_... method does not exist, call self.unknown_departure.
Method dispatch​_visit Call self."visit_ + node class name" with node as parameter. If the visit_... method does not exist, call self.unknown_visit.
Method unknown​_departure Called before exiting unknown Node types.
Method unknown​_visit Called when entering unknown Node types.
Class Variable optional Tuple containing node class names (as strings).
Instance Variable document Undocumented
def __init__(self, document):
overridden in docutils.nodes.TreeCopyVisitor, docutils.transforms.references.DanglingReferencesVisitor, docutils.writers._html_base.HTMLTranslator, docutils.writers.docutils_xml.XMLTranslator, docutils.writers.latex2e.LaTeXTranslator, docutils.writers.manpage.Translator, docutils.writers.odf_odt.ODFTranslator

Undocumented

def dispatch_departure(self, node):
Call self."depart_ + node class name" with node as parameter. If the depart_... method does not exist, call self.unknown_departure.
def dispatch_visit(self, node):
overridden in docutils.writers.odf_odt.ODFTranslator
Call self."visit_ + node class name" with node as parameter. If the visit_... method does not exist, call self.unknown_visit.
def unknown_departure(self, node):

Called before exiting unknown Node types.

Raise exception unless overridden.

def unknown_visit(self, node):
overridden in docutils.transforms.peps.PEPZeroSpecial, docutils.transforms.references.DanglingReferencesVisitor

Called when entering unknown Node types.

Raise an exception unless overridden.

optional: tuple[str, ...] =

Tuple containing node class names (as strings).

No exception will be raised if writers do not implement visit or departure functions for these node classes.

Used to ensure transitional compatibility with existing 3rd-party writers.

document =
overridden in docutils.transforms.references.DanglingReferencesVisitor

Undocumented