Source code for docutils.nodes

# $Id: nodes.py 8592 2020-12-15 23:06:26Z milde $
# Author: David Goodger <goodger@python.org>
# Maintainer: docutils-develop@lists.sourceforge.net
# Copyright: This module has been placed in the public domain.

"""
Docutils document tree element class library.

Classes in CamelCase are abstract base classes or auxiliary classes. The one
exception is `Text`, for a text (PCDATA) node; uppercase is used to
differentiate from element classes.  Classes in lower_case_with_underscores
are element classes, matching the XML element generic identifiers in the DTD_.

The position of each node (the level at which it can occur) is significant and
is represented by abstract base classes (`Root`, `Structural`, `Body`,
`Inline`, etc.).  Certain transformations will be easier because we can use
``isinstance(node, base_class)`` to determine the position of the node in the
hierarchy.

.. _DTD: http://docutils.sourceforge.net/docs/ref/docutils.dtd
"""
from __future__ import print_function
from collections import Counter

__docformat__ = 'reStructuredText'

import sys
import os
import re
import warnings
import unicodedata

if sys.version_info >= (3, 0):
    unicode = str  # noqa
    basestring = str  # noqa

class _traversal_list(list):
    # auxiliary class to report a FutureWarning
    done = False
    def _warning_decorator(fun):
        msg = ("\n   The iterable returned by Node.traverse()"
               "\n   will become an iterator instead of a list in "
               "Docutils > 0.16.")
        def wrapper(self, *args, **kwargs):
            if not self.done:
                warnings.warn(msg, FutureWarning, stacklevel=2)
            self.done = True
            return fun(self, *args, **kwargs)
        return wrapper

    __add__ = _warning_decorator(list.__add__)
    __contains__ = _warning_decorator(list.__contains__)
    __getitem__ = _warning_decorator(list.__getitem__)
    __reversed__ = _warning_decorator(list.__reversed__)
    __setitem__ = _warning_decorator(list.__setitem__)
    append = _warning_decorator(list.append)
    count = _warning_decorator(list.count)
    extend = _warning_decorator(list.extend)
    index = _warning_decorator(list.index)
    insert = _warning_decorator(list.insert)
    pop = _warning_decorator(list.pop)
    reverse = _warning_decorator(list.reverse)


# ==============================
#  Functional Node Base Classes
# ==============================

class Node(object):

    """Abstract base class of nodes in a document tree."""

    parent = None
    """Back-reference to the Node immediately containing this Node."""

    source = None
    """Path or description of the input source which generated this Node."""

    line = None
    """The line number (1-based) of the beginning of this Node in `source`."""

    _document = None

    @property
    def document(self):
        """
        Return the `document` node at the root of the tree containing this Node.
        """
        try:
            return self._document or self.parent.document
        except AttributeError:
            return None

    @document.setter
    def document(self, value):
        self._document = value

    def __bool__(self):
        """
        Node instances are always true, even if they're empty.  A node is more
        than a simple container.  Its boolean "truth" does not depend on
        having one or more subnodes in the doctree.

        Use `len()` to check node length.  Use `None` to represent a boolean
        false value.
        """
        return True

    if sys.version_info < (3, 0):
        __nonzero__ = __bool__

    if sys.version_info < (3, 0):
        # on 2.x, str(node) will be a byte string with Unicode
        # characters > 255 escaped; on 3.x this is no longer necessary
        def __str__(self):
            return unicode(self).encode('raw_unicode_escape')

    def asdom(self, dom=None):
        """Return a DOM **fragment** representation of this Node."""
        if dom is None:
            import xml.dom.minidom as dom
        domroot = dom.Document()
        return self._dom_node(domroot)

    def pformat(self, indent='    ', level=0):
        """
        Return an indented pseudo-XML representation, for test purposes.

        Override in subclasses.
        """
        raise NotImplementedError

    def copy(self):
        """Return a copy of self."""
        raise NotImplementedError

    def deepcopy(self):
        """Return a deep copy of self (also copying children)."""
        raise NotImplementedError

    def astext(self):
        """Return a string representation of this Node."""
        raise NotImplementedError

    def setup_child(self, child):
        child.parent = self
        if self.document:
            child.document = self.document
            if child.source is None:
                child.source = self.document.current_source
            if child.line is None:
                child.line = self.document.current_line

[docs] def walk(self, visitor): """ Traverse a tree of `Node` objects, calling the `dispatch_visit()` method of `visitor` when entering each node. (The `walkabout()` method is similar, except it also calls the `dispatch_departure()` method before exiting each node.) This tree traversal supports limited in-place tree modifications. Replacing one node with one or more nodes is OK, as is removing an element. However, if the node removed or replaced occurs after the current node, the old node will still be traversed, and any new nodes will not. Within ``visit`` methods (and ``depart`` methods for `walkabout()`), `TreePruningException` subclasses may be raised (`SkipChildren`, `SkipSiblings`, `SkipNode`, `SkipDeparture`). Parameter `visitor`: A `NodeVisitor` object, containing a ``visit`` implementation for each `Node` subclass encountered. Return true if we should stop the traversal. """ stop = False visitor.document.reporter.debug( 'docutils.nodes.Node.walk calling dispatch_visit for %s' % self.__class__.__name__) try: try: visitor.dispatch_visit(self) except (SkipChildren, SkipNode): return stop except SkipDeparture: # not applicable; ignore pass children = self.children try: for child in children[:]: if child.walk(visitor): stop = True break except SkipSiblings: pass except StopTraversal: stop = True return stop
[docs] def walkabout(self, visitor): """ Perform a tree traversal similarly to `Node.walk()` (which see), except also call the `dispatch_departure()` method before exiting each node. Parameter `visitor`: A `NodeVisitor` object, containing a ``visit`` and ``depart`` implementation for each `Node` subclass encountered. Return true if we should stop the traversal. """ call_depart = True stop = False visitor.document.reporter.debug( 'docutils.nodes.Node.walkabout calling dispatch_visit for %s' % self.__class__.__name__) try: try: visitor.dispatch_visit(self) except SkipNode: return stop except SkipDeparture: call_depart = False children = self.children try: for child in children[:]: if child.walkabout(visitor): stop = True break except SkipSiblings: pass except SkipChildren: pass except StopTraversal: stop = True if call_depart: visitor.document.reporter.debug( 'docutils.nodes.Node.walkabout calling dispatch_departure ' 'for %s' % self.__class__.__name__) visitor.dispatch_departure(self) return stop
def _fast_traverse(self, cls): """Return iterator that only supports instance checks.""" if isinstance(self, cls): yield self for child in self.children: for subnode in child._fast_traverse(cls): yield subnode def _all_traverse(self): """Return iterator that doesn't check for a condition.""" yield self for child in self.children: for subnode in child._all_traverse(): yield subnode def traverse(self, condition=None, include_self=True, descend=True, siblings=False, ascend=False): """ Return an iterable containing * self (if include_self is true) * all descendants in tree traversal order (if descend is true) * all siblings (if siblings is true) and their descendants (if also descend is true) * the siblings of the parent (if ascend is true) and their descendants (if also descend is true), and so on If `condition` is not None, the iterable contains only nodes for which ``condition(node)`` is true. If `condition` is a node class ``cls``, it is equivalent to a function consisting of ``return isinstance(node, cls)``. If ascend is true, assume siblings to be true as well. For example, given the following tree:: <paragraph> <emphasis> <--- emphasis.traverse() and <strong> <--- strong.traverse() are called. Foo Bar <reference name="Baz" refid="baz"> Baz Then list(emphasis.traverse()) equals :: [<emphasis>, <strong>, <#text: Foo>, <#text: Bar>] and list(strong.traverse(ascend=True)) equals :: [<strong>, <#text: Foo>, <#text: Bar>, <reference>, <#text: Baz>] """ # Although the documented API only promises an "iterable" as return # value, the implementation returned a list up to v. 0.15. Some 3rd # party code still relies on this (e.g. Sphinx as of 2019-09-07). # Therefore, let's return a list until this is sorted out: return _traversal_list(self._traverse(condition, include_self, descend, siblings, ascend)) def _traverse(self, condition=None, include_self=True, descend=True, siblings=False, ascend=False): """Return iterator over nodes following `self`. See `traverse()`.""" if ascend: siblings=True # Check for special argument combinations that allow using an # optimized version of traverse() if include_self and descend and not siblings: if condition is None: for subnode in self._all_traverse(): yield subnode return elif isinstance(condition, type): for subnode in self._fast_traverse(condition): yield subnode return # Check if `condition` is a class (check for TypeType for Python # implementations that use only new-style classes, like PyPy). if isinstance(condition, type): node_class = condition def condition(node, node_class=node_class): return isinstance(node, node_class) if include_self and (condition is None or condition(self)): yield self if descend and len(self.children): for child in self: for subnode in child._traverse(condition=condition, include_self=True, descend=True, siblings=False, ascend=False): yield subnode if siblings or ascend: node = self while node.parent: index = node.parent.index(node) for sibling in node.parent[index+1:]: for subnode in sibling._traverse(condition=condition, include_self=True, descend=descend, siblings=False, ascend=False): yield subnode if not ascend: break else: node = node.parent def next_node(self, condition=None, include_self=False, descend=True, siblings=False, ascend=False): """ Return the first node in the iterable returned by traverse(), or None if the iterable is empty. Parameter list is the same as of traverse. Note that include_self defaults to False, though. """ node_iterator = self._traverse(condition, include_self, descend, siblings, ascend) try: return next(node_iterator) except StopIteration: return None if sys.version_info < (3, 0): class reprunicode(unicode): """ A unicode sub-class that removes the initial u from unicode's repr. """ def __repr__(self): return unicode.__repr__(self)[1:] else: reprunicode = unicode def ensure_str(s): """ Failsave conversion of `unicode` to `str`. """ if sys.version_info < (3, 0) and isinstance(s, unicode): return s.encode('ascii', 'backslashreplace') return s # definition moved here from `utils` to avoid circular import dependency def unescape(text, restore_backslashes=False, respect_whitespace=False): """ Return a string with nulls removed or restored to backslashes. Backslash-escaped spaces are also removed. """ # `respect_whitespace` is ignored (since introduction 2016-12-16) if restore_backslashes: return text.replace('\x00', '\\') else: for sep in ['\x00 ', '\x00\n', '\x00']: text = ''.join(text.split(sep)) return text class Text(Node, reprunicode): """ Instances are terminal nodes (leaves) containing text only; no child nodes or attributes. Initialize by passing a string to the constructor. Access the text itself with the `astext` method. """ tagname = '#text' children = () """Text nodes have no children, and cannot have children.""" if sys.version_info > (3, 0): def __new__(cls, data, rawsource=None): """Prevent the rawsource argument from propagating to str.""" if isinstance(data, bytes): raise TypeError('expecting str data, not bytes') return reprunicode.__new__(cls, data) else: def __new__(cls, data, rawsource=None): """Prevent the rawsource argument from propagating to str.""" return reprunicode.__new__(cls, data) def __init__(self, data, rawsource=''): self.rawsource = rawsource """The raw text from which this element was constructed.""" def shortrepr(self, maxlen=18): data = self if len(data) > maxlen: data = data[:maxlen-4] + ' ...' return '<%s: %r>' % (self.tagname, reprunicode(data)) def __repr__(self): return self.shortrepr(maxlen=68) def _dom_node(self, domroot): return domroot.createTextNode(unicode(self)) def astext(self): return reprunicode(unescape(self)) # Note about __unicode__: The implementation of __unicode__ here, # and the one raising NotImplemented in the superclass Node had # to be removed when changing Text to a subclass of unicode instead # of UserString, since there is no way to delegate the __unicode__ # call to the superclass unicode: # unicode itself does not have __unicode__ method to delegate to # and calling unicode(self) or unicode.__new__ directly creates # an infinite loop def copy(self): return self.__class__(reprunicode(self), rawsource=self.rawsource) def deepcopy(self): return self.copy() def pformat(self, indent=' ', level=0): try: if self.document.settings.detailled: lines = ['%s%s' % (indent * level, '<#text>') ] + [indent*(level+1) + repr(line) for line in self.splitlines(keepends=True)] return '\n'.join(lines) + '\n' except AttributeError: pass indent = indent * level lines = [indent+line for line in self.astext().splitlines()] if not lines: return '' return '\n'.join(lines) + '\n' # rstrip and lstrip are used by substitution definitions where # they are expected to return a Text instance, this was formerly # taken care of by UserString. def rstrip(self, chars=None): return self.__class__(reprunicode.rstrip(self, chars), self.rawsource) def lstrip(self, chars=None): return self.__class__(reprunicode.lstrip(self, chars), self.rawsource) class Element(Node): """ `Element` is the superclass to all specific elements. Elements contain attributes and child nodes. Elements emulate dictionaries for attributes, indexing by attribute name (a string). To set the attribute 'att' to 'value', do:: element['att'] = 'value' There are two special attributes: 'ids' and 'names'. Both are lists of unique identifiers, and names serve as human interfaces to IDs. Names are case- and whitespace-normalized (see the fully_normalize_name() function), and IDs conform to the regular expression ``[a-z](-?[a-z0-9]+)*`` (see the make_id() function). Elements also emulate lists for child nodes (element nodes and/or text nodes), indexing by integer. To get the first child node, use:: element[0] Elements may be constructed using the ``+=`` operator. To add one new child node to element, do:: element += node This is equivalent to ``element.append(node)``. To add a list of multiple child nodes at once, use the same ``+=`` operator:: element += [node1, node2] This is equivalent to ``element.extend([node1, node2])``. """ basic_attributes = ('ids', 'classes', 'names', 'dupnames') """List attributes which are defined for every Element-derived class instance and can be safely transferred to a different node.""" local_attributes = ('backrefs',) """A list of class-specific attributes that should not be copied with the standard attributes when replacing a node. NOTE: Derived classes should override this value to prevent any of its attributes being copied by adding to the value in its parent class.""" list_attributes = basic_attributes + local_attributes """List attributes, automatically initialized to empty lists for all nodes.""" known_attributes = list_attributes + ('source', 'rawsource') """List attributes that are known to the Element base class.""" tagname = None """The element generic identifier. If None, it is set as an instance attribute to the name of the class.""" child_text_separator = '\n\n' """Separator for child nodes, used by `astext()` method.""" def __init__(self, rawsource='', *children, **attributes): self.rawsource = rawsource """The raw text from which this element was constructed. NOTE: some elements do not set this value (default ''). """ self.children = [] """List of child nodes (elements and/or `Text`).""" self.extend(children) # maintain parent info self.attributes = {} """Dictionary of attribute {name: value}.""" # Initialize list attributes. for att in self.list_attributes: self.attributes[att] = [] for att, value in attributes.items(): att = att.lower() if att in self.list_attributes: # mutable list; make a copy for this node self.attributes[att] = value[:] else: self.attributes[att] = value if self.tagname is None: self.tagname = self.__class__.__name__ def _dom_node(self, domroot): element = domroot.createElement(self.tagname) for attribute, value in self.attlist(): if isinstance(value, list): value = ' '.join([serial_escape('%s' % (v,)) for v in value]) element.setAttribute(attribute, '%s' % value) for child in self.children: element.appendChild(child._dom_node(domroot)) return element def __repr__(self): data = '' for c in self.children: data += c.shortrepr() if len(data) > 60: data = data[:56] + ' ...' break if self['names']: return '<%s "%s": %s>' % (self.__class__.__name__, '; '.join([ensure_str(n) for n in self['names']]), data) else: return '<%s: %s>' % (self.__class__.__name__, data) def shortrepr(self): if self['names']: return '<%s "%s"...>' % (self.__class__.__name__, '; '.join([ensure_str(n) for n in self['names']])) else: return '<%s...>' % self.tagname def __unicode__(self): if self.children: return u'%s%s%s' % (self.starttag(), ''.join([unicode(c) for c in self.children]), self.endtag()) else: return self.emptytag() if sys.version_info >= (3, 0): __str__ = __unicode__ def starttag(self, quoteattr=None): # the optional arg is used by the docutils_xml writer if quoteattr is None: quoteattr = pseudo_quoteattr parts = [self.tagname] for name, value in self.attlist(): if value is None: # boolean attribute parts.append('%s="True"' % name) continue if isinstance(value, list): values = [serial_escape('%s' % (v,)) for v in value] value = ' '.join(values) else: value = unicode(value) value = quoteattr(value) parts.append(u'%s=%s' % (name, value)) return u'<%s>' % u' '.join(parts) def endtag(self): return '</%s>' % self.tagname def emptytag(self): return u'<%s/>' % u' '.join([self.tagname] + ['%s="%s"' % (n, v) for n, v in self.attlist()]) def __len__(self): return len(self.children) def __contains__(self, key): # Test for both, children and attributes with operator ``in``. if isinstance(key, basestring): return key in self.attributes return key in self.children def __getitem__(self, key): if isinstance(key, basestring): return self.attributes[key] elif isinstance(key, int): return self.children[key] elif isinstance(key, slice): assert key.step in (None, 1), 'cannot handle slice with stride' return self.children[key.start:key.stop] else: raise TypeError('element index must be an integer, a slice, or ' 'an attribute name string') def __setitem__(self, key, item): if isinstance(key, basestring): self.attributes[str(key)] = item elif isinstance(key, int): self.setup_child(item) self.children[key] = item elif isinstance(key, slice): assert key.step in (None, 1), 'cannot handle slice with stride' for node in item: self.setup_child(node) self.children[key.start:key.stop] = item else: raise TypeError('element index must be an integer, a slice, or ' 'an attribute name string') def __delitem__(self, key): if isinstance(key, basestring): del self.attributes[key] elif isinstance(key, int): del self.children[key] elif isinstance(key, slice): assert key.step in (None, 1), 'cannot handle slice with stride' del self.children[key.start:key.stop] else: raise TypeError('element index must be an integer, a simple ' 'slice, or an attribute name string') def __add__(self, other): return self.children + other def __radd__(self, other): return other + self.children def __iadd__(self, other): """Append a node or a list of nodes to `self.children`.""" if isinstance(other, Node): self.append(other) elif other is not None: self.extend(other) return self def astext(self): return self.child_text_separator.join( [child.astext() for child in self.children]) def non_default_attributes(self): atts = {} for key, value in self.attributes.items(): if self.is_not_default(key): atts[key] = value return atts def attlist(self): attlist = sorted(self.non_default_attributes().items()) return attlist def get(self, key, failobj=None): return self.attributes.get(key, failobj) def hasattr(self, attr): return attr in self.attributes def delattr(self, attr): if attr in self.attributes: del self.attributes[attr] def setdefault(self, key, failobj=None): return self.attributes.setdefault(key, failobj) has_key = hasattr def get_language_code(self, fallback=''): """Return node's language tag. Look iteratively in self and parents for a class argument starting with ``language-`` and return the remainder of it (which should be a `BCP49` language tag) or the `fallback`. """ for cls in self.get('classes', []): if cls.startswith('language-'): return cls[9:] try: return self.parent.get_language(fallback) except AttributeError: return fallback def append(self, item): self.setup_child(item) self.children.append(item) def extend(self, item): for node in item: self.append(node) def insert(self, index, item): if isinstance(item, Node): self.setup_child(item) self.children.insert(index, item) elif item is not None: self[index:index] = item def pop(self, i=-1): return self.children.pop(i) def remove(self, item): self.children.remove(item) def index(self, item): return self.children.index(item) def is_not_default(self, key): if self[key] == [] and key in self.list_attributes: return 0 else: return 1 def update_basic_atts(self, dict_): """ Update basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') from node or dictionary `dict_`. """ if isinstance(dict_, Node): dict_ = dict_.attributes for att in self.basic_attributes: self.append_attr_list(att, dict_.get(att, [])) def append_attr_list(self, attr, values): """ For each element in values, if it does not exist in self[attr], append it. NOTE: Requires self[attr] and values to be sequence type and the former should specifically be a list. """ # List Concatenation for value in values: if not value in self[attr]: self[attr].append(value) def coerce_append_attr_list(self, attr, value): """ First, convert both self[attr] and value to a non-string sequence type; if either is not already a sequence, convert it to a list of one element. Then call append_attr_list. NOTE: self[attr] and value both must not be None. """ # List Concatenation if not isinstance(self.get(attr), list): self[attr] = [self[attr]] if not isinstance(value, list): value = [value] self.append_attr_list(attr, value) def replace_attr(self, attr, value, force = True): """ If self[attr] does not exist or force is True or omitted, set self[attr] to value, otherwise do nothing. """ # One or the other if force or self.get(attr) is None: self[attr] = value def copy_attr_convert(self, attr, value, replace = True): """ If attr is an attribute of self, set self[attr] to [self[attr], value], otherwise set self[attr] to value. NOTE: replace is not used by this function and is kept only for compatibility with the other copy functions. """ if self.get(attr) is not value: self.coerce_append_attr_list(attr, value) def copy_attr_coerce(self, attr, value, replace): """ If attr is an attribute of self and either self[attr] or value is a list, convert all non-sequence values to a sequence of 1 element and then concatenate the two sequence, setting the result to self[attr]. If both self[attr] and value are non-sequences and replace is True or self[attr] is None, replace self[attr] with value. Otherwise, do nothing. """ if self.get(attr) is not value: if isinstance(self.get(attr), list) or \ isinstance(value, list): self.coerce_append_attr_list(attr, value) else: self.replace_attr(attr, value, replace) def copy_attr_concatenate(self, attr, value, replace): """ If attr is an attribute of self and both self[attr] and value are lists, concatenate the two sequences, setting the result to self[attr]. If either self[attr] or value are non-sequences and replace is True or self[attr] is None, replace self[attr] with value. Otherwise, do nothing. """ if self.get(attr) is not value: if isinstance(self.get(attr), list) and \ isinstance(value, list): self.append_attr_list(attr, value) else: self.replace_attr(attr, value, replace) def copy_attr_consistent(self, attr, value, replace): """ If replace is True or self[attr] is None, replace self[attr] with value. Otherwise, do nothing. """ if self.get(attr) is not value: self.replace_attr(attr, value, replace) def update_all_atts(self, dict_, update_fun = copy_attr_consistent, replace = True, and_source = False): """ Updates all attributes from node or dictionary `dict_`. Appends the basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') and then, for all other attributes in dict_, updates the same attribute in self. When attributes with the same identifier appear in both self and dict_, the two values are merged based on the value of update_fun. Generally, when replace is True, the values in self are replaced or merged with the values in dict_; otherwise, the values in self may be preserved or merged. When and_source is True, the 'source' attribute is included in the copy. NOTE: When replace is False, and self contains a 'source' attribute, 'source' is not replaced even when dict_ has a 'source' attribute, though it may still be merged into a list depending on the value of update_fun. NOTE: It is easier to call the update-specific methods then to pass the update_fun method to this function. """ if isinstance(dict_, Node): dict_ = dict_.attributes # Include the source attribute when copying? if and_source: filter_fun = self.is_not_list_attribute else: filter_fun = self.is_not_known_attribute # Copy the basic attributes self.update_basic_atts(dict_) # Grab other attributes in dict_ not in self except the # (All basic attributes should be copied already) for att in filter(filter_fun, dict_): update_fun(self, att, dict_[att], replace) def update_all_atts_consistantly(self, dict_, replace = True, and_source = False): """ Updates all attributes from node or dictionary `dict_`. Appends the basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') and then, for all other attributes in dict_, updates the same attribute in self. When attributes with the same identifier appear in both self and dict_ and replace is True, the values in self are replaced with the values in dict_; otherwise, the values in self are preserved. When and_source is True, the 'source' attribute is included in the copy. NOTE: When replace is False, and self contains a 'source' attribute, 'source' is not replaced even when dict_ has a 'source' attribute, though it may still be merged into a list depending on the value of update_fun. """ self.update_all_atts(dict_, Element.copy_attr_consistent, replace, and_source) def update_all_atts_concatenating(self, dict_, replace = True, and_source = False): """ Updates all attributes from node or dictionary `dict_`. Appends the basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') and then, for all other attributes in dict_, updates the same attribute in self. When attributes with the same identifier appear in both self and dict_ whose values aren't each lists and replace is True, the values in self are replaced with the values in dict_; if the values from self and dict_ for the given identifier are both of list type, then the two lists are concatenated and the result stored in self; otherwise, the values in self are preserved. When and_source is True, the 'source' attribute is included in the copy. NOTE: When replace is False, and self contains a 'source' attribute, 'source' is not replaced even when dict_ has a 'source' attribute, though it may still be merged into a list depending on the value of update_fun. """ self.update_all_atts(dict_, Element.copy_attr_concatenate, replace, and_source) def update_all_atts_coercion(self, dict_, replace = True, and_source = False): """ Updates all attributes from node or dictionary `dict_`. Appends the basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') and then, for all other attributes in dict_, updates the same attribute in self. When attributes with the same identifier appear in both self and dict_ whose values are both not lists and replace is True, the values in self are replaced with the values in dict_; if either of the values from self and dict_ for the given identifier are of list type, then first any non-lists are converted to 1-element lists and then the two lists are concatenated and the result stored in self; otherwise, the values in self are preserved. When and_source is True, the 'source' attribute is included in the copy. NOTE: When replace is False, and self contains a 'source' attribute, 'source' is not replaced even when dict_ has a 'source' attribute, though it may still be merged into a list depending on the value of update_fun. """ self.update_all_atts(dict_, Element.copy_attr_coerce, replace, and_source) def update_all_atts_convert(self, dict_, and_source = False): """ Updates all attributes from node or dictionary `dict_`. Appends the basic attributes ('ids', 'names', 'classes', 'dupnames', but not 'source') and then, for all other attributes in dict_, updates the same attribute in self. When attributes with the same identifier appear in both self and dict_ then first any non-lists are converted to 1-element lists and then the two lists are concatenated and the result stored in self; otherwise, the values in self are preserved. When and_source is True, the 'source' attribute is included in the copy. NOTE: When replace is False, and self contains a 'source' attribute, 'source' is not replaced even when dict_ has a 'source' attribute, though it may still be merged into a list depending on the value of update_fun. """ self.update_all_atts(dict_, Element.copy_attr_convert, and_source = and_source) def clear(self): self.children = [] def replace(self, old, new): """Replace one child `Node` with another child or children.""" index = self.index(old) if isinstance(new, Node): self.setup_child(new) self[index] = new elif new is not None: self[index:index+1] = new def replace_self(self, new): """ Replace `self` node with `new`, where `new` is a node or a list of nodes. """ update = new if not isinstance(new, Node): # `new` is a list; update first child. try: update = new[0] except IndexError: update = None if isinstance(update, Element): update.update_basic_atts(self) else: # `update` is a Text node or `new` is an empty list. # Assert that we aren't losing any attributes. for att in self.basic_attributes: assert not self[att], \ 'Losing "%s" attribute: %s' % (att, self[att]) self.parent.replace(self, new) def first_child_matching_class(self, childclass, start=0, end=sys.maxsize): """ Return the index of the first child whose class exactly matches. Parameters: - `childclass`: A `Node` subclass to search for, or a tuple of `Node` classes. If a tuple, any of the classes may match. - `start`: Initial index to check. - `end`: Initial index to *not* check. """ if not isinstance(childclass, tuple): childclass = (childclass,) for index in range(start, min(len(self), end)): for c in childclass: if isinstance(self[index], c): return index return None def first_child_not_matching_class(self, childclass, start=0, end=sys.maxsize): """ Return the index of the first child whose class does *not* match. Parameters: - `childclass`: A `Node` subclass to skip, or a tuple of `Node` classes. If a tuple, none of the classes may match. - `start`: Initial index to check. - `end`: Initial index to *not* check. """ if not isinstance(childclass, tuple): childclass = (childclass,) for index in range(start, min(len(self), end)): for c in childclass: if isinstance(self.children[index], c): break else: return index return None def pformat(self, indent=' ', level=0): return ''.join(['%s%s\n' % (indent * level, self.starttag())] + [child.pformat(indent, level+1) for child in self.children]) def copy(self): obj = self.__class__(rawsource=self.rawsource, **self.attributes) obj._document = self._document obj.source = self.source obj.line = self.line return obj def deepcopy(self): copy = self.copy() copy.extend([child.deepcopy() for child in self.children]) return copy def set_class(self, name): """Add a new class to the "classes" attribute.""" warnings.warn('docutils.nodes.Element.set_class deprecated; ' "append to Element['classes'] list attribute directly", DeprecationWarning, stacklevel=2) assert ' ' not in name self['classes'].append(name.lower()) def note_referenced_by(self, name=None, id=None): """Note that this Element has been referenced by its name `name` or id `id`.""" self.referenced = 1 # Element.expect_referenced_by_* dictionaries map names or ids # to nodes whose ``referenced`` attribute is set to true as # soon as this node is referenced by the given name or id. # Needed for target propagation. by_name = getattr(self, 'expect_referenced_by_name', {}).get(name) by_id = getattr(self, 'expect_referenced_by_id', {}).get(id) if by_name: assert name is not None by_name.referenced = 1 if by_id: assert id is not None by_id.referenced = 1 @classmethod def is_not_list_attribute(cls, attr): """ Returns True if and only if the given attribute is NOT one of the basic list attributes defined for all Elements. """ return attr not in cls.list_attributes @classmethod def is_not_known_attribute(cls, attr): """ Returns True if and only if the given attribute is NOT recognized by this class. """ return attr not in cls.known_attributes class TextElement(Element): """ An element which directly contains text. Its children are all `Text` or `Inline` subclass nodes. You can check whether an element's context is inline simply by checking whether its immediate parent is a `TextElement` instance (including subclasses). This is handy for nodes like `image` that can appear both inline and as standalone body elements. If passing children to `__init__()`, make sure to set `text` to ``''`` or some other suitable value. """ child_text_separator = '' """Separator for child nodes, used by `astext()` method.""" def __init__(self, rawsource='', text='', *children, **attributes): if text != '': textnode = Text(text) Element.__init__(self, rawsource, textnode, *children, **attributes) else: Element.__init__(self, rawsource, *children, **attributes) class FixedTextElement(TextElement): """An element which directly contains preformatted text.""" def __init__(self, rawsource='', text='', *children, **attributes): TextElement.__init__(self, rawsource, text, *children, **attributes) self.attributes['xml:space'] = 'preserve' # ======== # Mixins # ======== class Resolvable(object): resolved = 0 class BackLinkable(object): def add_backref(self, refid): self['backrefs'].append(refid) # ==================== # Element Categories # ==================== class Root(object): pass class Titular(object): pass class PreBibliographic(object): """Category of Node which may occur before Bibliographic Nodes.""" class Bibliographic(object): pass class Decorative(PreBibliographic): pass class Structural(object): pass class Body(object): pass class General(Body): pass class Sequential(Body): """List-like elements.""" class Admonition(Body): pass class Special(Body): """Special internal body elements.""" class Invisible(PreBibliographic): """Internal elements that don't appear in output.""" class Part(object): pass class Inline(object): pass class Referential(Resolvable): pass class Targetable(Resolvable): referenced = 0 indirect_reference_name = None """Holds the whitespace_normalized_name (contains mixed case) of a target. Required for MoinMoin/reST compatibility.""" class Labeled(object): """Contains a `label` as its first element.""" # ============== # Root Element # ============== class document(Root, Structural, Element): """ The document root element. Do not instantiate this class directly; use `docutils.utils.new_document()` instead. """ def __init__(self, settings, reporter, *args, **kwargs): Element.__init__(self, *args, **kwargs) self.current_source = None """Path to or description of the input source being processed.""" self.current_line = None """Line number (1-based) of `current_source`.""" self.settings = settings """Runtime settings data record.""" self.reporter = reporter """System message generator.""" self.indirect_targets = [] """List of indirect target nodes.""" self.substitution_defs = {} """Mapping of substitution names to substitution_definition nodes.""" self.substitution_names = {} """Mapping of case-normalized substitution names to case-sensitive names.""" self.refnames = {} """Mapping of names to lists of referencing nodes.""" self.refids = {} """Mapping of ids to lists of referencing nodes.""" self.nameids = {} """Mapping of names to unique id's.""" self.nametypes = {} """Mapping of names to hyperlink type (boolean: True => explicit, False => implicit.""" self.ids = {} """Mapping of ids to nodes.""" self.footnote_refs = {} """Mapping of footnote labels to lists of footnote_reference nodes.""" self.citation_refs = {} """Mapping of citation labels to lists of citation_reference nodes.""" self.autofootnotes = [] """List of auto-numbered footnote nodes.""" self.autofootnote_refs = [] """List of auto-numbered footnote_reference nodes.""" self.symbol_footnotes = [] """List of symbol footnote nodes.""" self.symbol_footnote_refs = [] """List of symbol footnote_reference nodes.""" self.footnotes = [] """List of manually-numbered footnote nodes.""" self.citations = [] """List of citation nodes.""" self.autofootnote_start = 1 """Initial auto-numbered footnote number.""" self.symbol_footnote_start = 0 """Initial symbol footnote symbol index.""" self.id_counter = Counter() """Numbers added to otherwise identical IDs.""" self.parse_messages = [] """System messages generated while parsing.""" self.transform_messages = [] """System messages generated while applying transforms.""" import docutils.transforms self.transformer = docutils.transforms.Transformer(self) """Storage for transforms to be applied to this document.""" self.include_log = [] """The current source's parents (to detect inclusion loops).""" self.decoration = None """Document's `decoration` node.""" self._document = self def __getstate__(self): """ Return dict with unpicklable references removed. """ state = self.__dict__.copy() state['reporter'] = None state['transformer'] = None return state def asdom(self, dom=None): """Return a DOM representation of this document.""" if dom is None: import xml.dom.minidom as dom domroot = dom.Document() domroot.appendChild(self._dom_node(domroot)) return domroot def set_id(self, node, msgnode=None, suggested_prefix=''): if node['ids']: # register and check for duplicates for id in node['ids']: self.ids.setdefault(id, node) if self.ids[id] is not node: msg = self.reporter.severe('Duplicate ID: "%s".' % id) if msgnode != None: msgnode += msg return id # generate and set id id_prefix = self.settings.id_prefix auto_id_prefix = self.settings.auto_id_prefix base_id = '' id = '' for name in node['names']: base_id = make_id(name) id = id_prefix + base_id # TODO: allow names starting with numbers if `id_prefix` # is non-empty: id = make_id(id_prefix + name) if base_id and id not in self.ids: break else: if base_id and auto_id_prefix.endswith('%'): # disambiguate name-derived ID # TODO: remove second condition after announcing change prefix = id + '-' else: prefix = id_prefix + auto_id_prefix if prefix.endswith('%'): prefix = '%s%s-' % (prefix[:-1], suggested_prefix or make_id(node.tagname)) while True: self.id_counter[prefix] += 1 id = '%s%d' % (prefix, self.id_counter[prefix]) if id not in self.ids: break node['ids'].append(id) self.ids[id] = node return id def set_name_id_map(self, node, id, msgnode=None, explicit=None): """ `self.nameids` maps names to IDs, while `self.nametypes` maps names to booleans representing hyperlink type (True==explicit, False==implicit). This method updates the mappings. The following state transition table shows how `self.nameids` ("ids") and `self.nametypes` ("types") change with new input (a call to this method), and what actions are performed ("implicit"-type system messages are INFO/1, and "explicit"-type system messages are ERROR/3): ==== ===== ======== ======== ======= ==== ===== ===== Old State Input Action New State Notes ----------- -------- ----------------- ----------- ----- ids types new type sys.msg. dupname ids types ==== ===== ======== ======== ======= ==== ===== ===== - - explicit - - new True - - implicit - - new False None False explicit - - new True old False explicit implicit old new True None True explicit explicit new None True old True explicit explicit new,old None True [#]_ None False implicit implicit new None False old False implicit implicit new,old None False None True implicit implicit new None True old True implicit implicit new old True ==== ===== ======== ======== ======= ==== ===== ===== .. [#] Do not clear the name-to-id map or invalidate the old target if both old and new targets are external and refer to identical URIs. The new target is invalidated regardless. """ for name in node['names']: if name in self.nameids: self.set_duplicate_name_id(node, id, name, msgnode, explicit) else: self.nameids[name] = id self.nametypes[name] = explicit def set_duplicate_name_id(self, node, id, name, msgnode, explicit): old_id = self.nameids[name] old_explicit = self.nametypes[name] self.nametypes[name] = old_explicit or explicit if explicit: if old_explicit: level = 2 if old_id is not None: old_node = self.ids[old_id] if 'refuri' in node: refuri = node['refuri'] if old_node['names'] \ and 'refuri' in old_node \ and old_node['refuri'] == refuri: level = 1 # just inform if refuri's identical if level > 1: dupname(old_node, name) self.nameids[name] = None msg = self.reporter.system_message( level, 'Duplicate explicit target name: "%s".' % name, backrefs=[id], base_node=node) if msgnode != None: msgnode += msg dupname(node, name) else: self.nameids[name] = id if old_id is not None: old_node = self.ids[old_id] dupname(old_node, name) else: if old_id is not None and not old_explicit: self.nameids[name] = None old_node = self.ids[old_id] dupname(old_node, name) dupname(node, name) if not explicit or (not old_explicit and old_id is not None): msg = self.reporter.info( 'Duplicate implicit target name: "%s".' % name, backrefs=[id], base_node=node) if msgnode != None: msgnode += msg def has_name(self, name): return name in self.nameids # "note" here is an imperative verb: "take note of". def note_implicit_target(self, target, msgnode=None): id = self.set_id(target, msgnode) self.set_name_id_map(target, id, msgnode, explicit=None) def note_explicit_target(self, target, msgnode=None): id = self.set_id(target, msgnode) self.set_name_id_map(target, id, msgnode, explicit=True) def note_refname(self, node): self.refnames.setdefault(node['refname'], []).append(node) def note_refid(self, node): self.refids.setdefault(node['refid'], []).append(node) def note_indirect_target(self, target): self.indirect_targets.append(target) if target['names']: self.note_refname(target) def note_anonymous_target(self, target): self.set_id(target) def note_autofootnote(self, footnote): self.set_id(footnote) self.autofootnotes.append(footnote) def note_autofootnote_ref(self, ref): self.set_id(ref) self.autofootnote_refs.append(ref) def note_symbol_footnote(self, footnote): self.set_id(footnote) self.symbol_footnotes.append(footnote) def note_symbol_footnote_ref(self, ref): self.set_id(ref) self.symbol_footnote_refs.append(ref) def note_footnote(self, footnote): self.set_id(footnote) self.footnotes.append(footnote) def note_footnote_ref(self, ref): self.set_id(ref) self.footnote_refs.setdefault(ref['refname'], []).append(ref) self.note_refname(ref) def note_citation(self, citation): self.citations.append(citation) def note_citation_ref(self, ref): self.set_id(ref) self.citation_refs.setdefault(ref['refname'], []).append(ref) self.note_refname(ref) def note_substitution_def(self, subdef, def_name, msgnode=None): name = whitespace_normalize_name(def_name) if name in self.substitution_defs: msg = self.reporter.error( 'Duplicate substitution definition name: "%s".' % name, base_node=subdef) if msgnode != None: msgnode += msg oldnode = self.substitution_defs[name] dupname(oldnode, name) # keep only the last definition: self.substitution_defs[name] = subdef # case-insensitive mapping: self.substitution_names[fully_normalize_name(name)] = name def note_substitution_ref(self, subref, refname): subref['refname'] = whitespace_normalize_name(refname) def note_pending(self, pending, priority=None): self.transformer.add_pending(pending, priority) def note_parse_message(self, message): self.parse_messages.append(message) def note_transform_message(self, message): self.transform_messages.append(message) def note_source(self, source, offset): self.current_source = source if offset is None: self.current_line = offset else: self.current_line = offset + 1 def copy(self): obj = self.__class__(self.settings, self.reporter, **self.attributes) obj.source = self.source obj.line = self.line return obj def get_decoration(self): if not self.decoration: self.decoration = decoration() index = self.first_child_not_matching_class(Titular) if index is None: self.append(self.decoration) else: self.insert(index, self.decoration) return self.decoration # ================ # Title Elements # ================ class title(Titular, PreBibliographic, TextElement): pass class subtitle(Titular, PreBibliographic, TextElement): pass class rubric(Titular, TextElement): pass # ======================== # Bibliographic Elements # ======================== class docinfo(Bibliographic, Element): pass class author(Bibliographic, TextElement): pass class authors(Bibliographic, Element): pass class organization(Bibliographic, TextElement): pass class address(Bibliographic, FixedTextElement): pass class contact(Bibliographic, TextElement): pass class version(Bibliographic, TextElement): pass class revision(Bibliographic, TextElement): pass class status(Bibliographic, TextElement): pass class date(Bibliographic, TextElement): pass class copyright(Bibliographic, TextElement): pass # ===================== # Decorative Elements # ===================== class decoration(Decorative, Element): def get_header(self): if not len(self.children) or not isinstance(self.children[0], header): self.insert(0, header()) return self.children[0] def get_footer(self): if not len(self.children) or not isinstance(self.children[-1], footer): self.append(footer()) return self.children[-1] class header(Decorative, Element): pass class footer(Decorative, Element): pass # ===================== # Structural Elements # ===================== class section(Structural, Element): pass class topic(Structural, Element): """ Topics are terminal, "leaf" mini-sections, like block quotes with titles, or textual figures. A topic is just like a section, except that it has no subsections, and it doesn't have to conform to section placement rules. Topics are allowed wherever body elements (list, table, etc.) are allowed, but only at the top level of a section or document. Topics cannot nest inside topics, sidebars, or body elements; you can't have a topic inside a table, list, block quote, etc. """ class sidebar(Structural, Element): """ Sidebars are like miniature, parallel documents that occur inside other documents, providing related or reference material. A sidebar is typically offset by a border and "floats" to the side of the page; the document's main text may flow around it. Sidebars can also be likened to super-footnotes; their content is outside of the flow of the document's main text. Sidebars are allowed wherever body elements (list, table, etc.) are allowed, but only at the top level of a section or document. Sidebars cannot nest inside sidebars, topics, or body elements; you can't have a sidebar inside a table, list, block quote, etc. """ class transition(Structural, Element): pass # =============== # Body Elements # =============== class paragraph(General, TextElement): pass class compound(General, Element): pass class container(General, Element): pass class bullet_list(Sequential, Element): pass class enumerated_list(Sequential, Element): pass class list_item(Part, Element): pass class definition_list(Sequential, Element): pass class definition_list_item(Part, Element): pass class term(Part, TextElement): pass class classifier(Part, TextElement): pass class definition(Part, Element): pass class field_list(Sequential, Element): pass class field(Part, Element): pass class field_name(Part, TextElement): pass class field_body(Part, Element): pass class option(Part, Element): child_text_separator = '' class option_argument(Part, TextElement): def astext(self): return self.get('delimiter', ' ') + TextElement.astext(self) class option_group(Part, Element): child_text_separator = ', ' class option_list(Sequential, Element): pass class option_list_item(Part, Element): child_text_separator = ' ' class option_string(Part, TextElement): pass class description(Part, Element): pass class literal_block(General, FixedTextElement): pass class doctest_block(General, FixedTextElement): pass class math_block(General, FixedTextElement): pass class line_block(General, Element): pass class line(Part, TextElement): indent = None class block_quote(General, Element): pass class attribution(Part, TextElement): pass class attention(Admonition, Element): pass class caution(Admonition, Element): pass class danger(Admonition, Element): pass class error(Admonition, Element): pass class important(Admonition, Element): pass class note(Admonition, Element): pass class tip(Admonition, Element): pass class hint(Admonition, Element): pass class warning(Admonition, Element): pass class admonition(Admonition, Element): pass class comment(Special, Invisible, FixedTextElement): pass class substitution_definition(Special, Invisible, TextElement): pass class target(Special, Invisible, Inline, TextElement, Targetable): pass class footnote(General, BackLinkable, Element, Labeled, Targetable): pass class citation(General, BackLinkable, Element, Labeled, Targetable): pass class label(Part, TextElement): pass class figure(General, Element): pass class caption(Part, TextElement): pass class legend(Part, Element): pass class table(General, Element): pass class tgroup(Part, Element): pass class colspec(Part, Element): pass class thead(Part, Element): pass class tbody(Part, Element): pass class row(Part, Element): pass class entry(Part, Element): pass class system_message(Special, BackLinkable, PreBibliographic, Element): """ System message element. Do not instantiate this class directly; use ``document.reporter.info/warning/error/severe()`` instead. """ def __init__(self, message=None, *children, **attributes): rawsource = attributes.pop('rawsource', '') if message: p = paragraph('', message) children = (p,) + children try: Element.__init__(self, rawsource, *children, **attributes) except: print('system_message: children=%r' % (children,)) raise def astext(self): line = self.get('line', '') return u'%s:%s: (%s/%s) %s' % (self['source'], line, self['type'], self['level'], Element.astext(self)) class pending(Special, Invisible, Element): """ The "pending" element is used to encapsulate a pending operation: the operation (transform), the point at which to apply it, and any data it requires. Only the pending operation's location within the document is stored in the public document tree (by the "pending" object itself); the operation and its data are stored in the "pending" object's internal instance attributes. For example, say you want a table of contents in your reStructuredText document. The easiest way to specify where to put it is from within the document, with a directive:: .. contents:: But the "contents" directive can't do its work until the entire document has been parsed and possibly transformed to some extent. So the directive code leaves a placeholder behind that will trigger the second phase of its processing, something like this:: <pending ...public attributes...> + internal attributes Use `document.note_pending()` so that the `docutils.transforms.Transformer` stage of processing can run all pending transforms. """ def __init__(self, transform, details=None, rawsource='', *children, **attributes): Element.__init__(self, rawsource, *children, **attributes) self.transform = transform """The `docutils.transforms.Transform` class implementing the pending operation.""" self.details = details or {} """Detail data (dictionary) required by the pending operation.""" def pformat(self, indent=' ', level=0): internals = [ '.. internal attributes:', ' .transform: %s.%s' % (self.transform.__module__, self.transform.__name__), ' .details:'] details = sorted(self.details.items()) for key, value in details: if isinstance(value, Node): internals.append('%7s%s:' % ('', key)) internals.extend(['%9s%s' % ('', line) for line in value.pformat().splitlines()]) elif value and isinstance(value, list) \ and isinstance(value[0], Node): internals.append('%7s%s:' % ('', key)) for v in value: internals.extend(['%9s%s' % ('', line) for line in v.pformat().splitlines()]) else: internals.append('%7s%s: %r' % ('', key, value)) return (Element.pformat(self, indent, level) + ''.join([(' %s%s\n' % (indent * level, line)) for line in internals])) def copy(self): obj = self.__class__(self.transform, self.details, self.rawsource, **self.attributes) obj._document = self._document obj.source = self.source obj.line = self.line return obj class raw(Special, Inline, PreBibliographic, FixedTextElement): """ Raw data that is to be passed untouched to the Writer. """ pass # ================= # Inline Elements # ================= class emphasis(Inline, TextElement): pass class strong(Inline, TextElement): pass class literal(Inline, TextElement): pass class reference(General, Inline, Referential, TextElement): pass class footnote_reference(Inline, Referential, TextElement): pass class citation_reference(Inline, Referential, TextElement): pass class substitution_reference(Inline, TextElement): pass class title_reference(Inline, TextElement): pass class abbreviation(Inline, TextElement): pass class acronym(Inline, TextElement): pass class superscript(Inline, TextElement): pass class subscript(Inline, TextElement): pass class math(Inline, TextElement): pass class image(General, Inline, Element): def astext(self): return self.get('alt', '') class inline(Inline, TextElement): pass class problematic(Inline, TextElement): pass class generated(Inline, TextElement): pass # ======================================== # Auxiliary Classes, Functions, and Data # ======================================== node_class_names = """ Text abbreviation acronym address admonition attention attribution author authors block_quote bullet_list caption caution citation citation_reference classifier colspec comment compound contact container copyright danger date decoration definition definition_list definition_list_item description docinfo doctest_block document emphasis entry enumerated_list error field field_body field_list field_name figure footer footnote footnote_reference generated header hint image important inline label legend line line_block list_item literal literal_block math math_block note option option_argument option_group option_list option_list_item option_string organization paragraph pending problematic raw reference revision row rubric section sidebar status strong subscript substitution_definition substitution_reference subtitle superscript system_message table target tbody term tgroup thead tip title title_reference topic transition version warning""".split() """A list of names of all concrete Node subclasses."""
[docs]class NodeVisitor(object): """ "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 should be implemented for *all* node types encountered (such as for `docutils.writers.Writer` subclasses). Unimplemented methods will raise exceptions. 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. """ optional = () """ 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. """ def __init__(self, document): self.document = document
[docs] def dispatch_visit(self, node): """ Call self."``visit_`` + node class name" with `node` as parameter. If the ``visit_...`` method does not exist, call self.unknown_visit. """ node_name = node.__class__.__name__ method = getattr(self, 'visit_' + node_name, self.unknown_visit) self.document.reporter.debug( 'docutils.nodes.NodeVisitor.dispatch_visit calling %s for %s' % (method.__name__, node_name)) return method(node)
[docs] 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. """ node_name = node.__class__.__name__ method = getattr(self, 'depart_' + node_name, self.unknown_departure) self.document.reporter.debug( 'docutils.nodes.NodeVisitor.dispatch_departure calling %s for %s' % (method.__name__, node_name)) return method(node)
def unknown_visit(self, node): """ Called when entering unknown `Node` types. Raise an exception unless overridden. """ if (self.document.settings.strict_visitor or node.__class__.__name__ not in self.optional): raise NotImplementedError( '%s visiting unknown node type: %s' % (self.__class__, node.__class__.__name__)) def unknown_departure(self, node): """ Called before exiting unknown `Node` types. Raise exception unless overridden. """ if (self.document.settings.strict_visitor or node.__class__.__name__ not in self.optional): raise NotImplementedError( '%s departing unknown node type: %s' % (self.__class__, node.__class__.__name__))
class SparseNodeVisitor(NodeVisitor): """ Base class for sparse traversals, where only certain node types are of interest. When ``visit_...`` & ``depart_...`` methods should be implemented for *all* node types (such as for `docutils.writers.Writer` subclasses), subclass `NodeVisitor` instead. """ class GenericNodeVisitor(NodeVisitor): """ Generic "Visitor" abstract superclass, for simple traversals. Unless overridden, each ``visit_...`` method calls `default_visit()`, and each ``depart_...`` method (when using `Node.walkabout()`) calls `default_departure()`. `default_visit()` (and `default_departure()`) must be overridden in subclasses. Define fully generic visitors by overriding `default_visit()` (and `default_departure()`) only. Define semi-generic visitors by overriding individual ``visit_...()`` (and ``depart_...()``) methods also. `NodeVisitor.unknown_visit()` (`NodeVisitor.unknown_departure()`) should be overridden for default behavior. """ def default_visit(self, node): """Override for generic, uniform traversals.""" raise NotImplementedError def default_departure(self, node): """Override for generic, uniform traversals.""" raise NotImplementedError def _call_default_visit(self, node): self.default_visit(node) def _call_default_departure(self, node): self.default_departure(node) def _nop(self, node): pass def _add_node_class_names(names): """Save typing with dynamic assignments:""" for _name in names: setattr(GenericNodeVisitor, "visit_" + _name, _call_default_visit) setattr(GenericNodeVisitor, "depart_" + _name, _call_default_departure) setattr(SparseNodeVisitor, 'visit_' + _name, _nop) setattr(SparseNodeVisitor, 'depart_' + _name, _nop) _add_node_class_names(node_class_names) class TreeCopyVisitor(GenericNodeVisitor): """ Make a complete copy of a tree or branch, including element attributes. """ def __init__(self, document): GenericNodeVisitor.__init__(self, document) self.parent_stack = [] self.parent = [] def get_tree_copy(self): return self.parent[0] def default_visit(self, node): """Copy the current node, and make it the new acting parent.""" newnode = node.copy() self.parent.append(newnode) self.parent_stack.append(self.parent) self.parent = newnode def default_departure(self, node): """Restore the previous acting parent.""" self.parent = self.parent_stack.pop() class TreePruningException(Exception): """ Base class for `NodeVisitor`-related tree pruning exceptions. Raise subclasses from within ``visit_...`` or ``depart_...`` methods called from `Node.walk()` and `Node.walkabout()` tree traversals to prune the tree traversed. """ pass class SkipChildren(TreePruningException): """ Do not visit any children of the current node. The current node's siblings and ``depart_...`` method are not affected. """ pass class SkipSiblings(TreePruningException): """ Do not visit any more siblings (to the right) of the current node. The current node's children and its ``depart_...`` method are not affected. """ pass class SkipNode(TreePruningException): """ Do not visit the current node's children, and do not call the current node's ``depart_...`` method. """ pass class SkipDeparture(TreePruningException): """ Do not call the current node's ``depart_...`` method. The current node's children and siblings are not affected. """ pass class NodeFound(TreePruningException): """ Raise to indicate that the target of a search has been found. This exception must be caught by the client; it is not caught by the traversal code. """ pass class StopTraversal(TreePruningException): """ Stop the traversal alltogether. The current node's ``depart_...`` method is not affected. The parent nodes ``depart_...`` methods are also called as usual. No other nodes are visited. This is an alternative to NodeFound that does not cause exception handling to trickle up to the caller. """ pass def make_id(string): """ Convert `string` into an identifier and return it. Docutils identifiers will conform to the regular expression ``[a-z](-?[a-z0-9]+)*``. For CSS compatibility, identifiers (the "class" and "id" attributes) should have no underscores, colons, or periods. Hyphens may be used. - The `HTML 4.01 spec`_ defines identifiers based on SGML tokens: ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods ("."). - However the `CSS1 spec`_ defines identifiers based on the "name" token, a tighter interpretation ("flex" tokenizer notation; "latin1" and "escape" 8-bit characters have been replaced with entities):: unicode \\[0-9a-f]{1,4} latin1 [&iexcl;-&yuml;] escape {unicode}|\\[ -~&iexcl;-&yuml;] nmchar [-a-z0-9]|{latin1}|{escape} name {nmchar}+ The CSS1 "nmchar" rule does not include underscores ("_"), colons (":"), or periods ("."), therefore "class" and "id" attributes should not contain these characters. They should be replaced with hyphens ("-"). Combined with HTML's requirements (the first character must be a letter; no "unicode", "latin1", or "escape" characters), this results in the ``[a-z](-?[a-z0-9]+)*`` pattern. .. _HTML 4.01 spec: http://www.w3.org/TR/html401 .. _CSS1 spec: http://www.w3.org/TR/REC-CSS1 """ id = string.lower() if not isinstance(id, unicode): id = id.decode() id = id.translate(_non_id_translate_digraphs) id = id.translate(_non_id_translate) # get rid of non-ascii characters. # 'ascii' lowercase to prevent problems with turkish locale. id = unicodedata.normalize('NFKD', id).\ encode('ascii', 'ignore').decode('ascii') # shrink runs of whitespace and replace by hyphen id = _non_id_chars.sub('-', ' '.join(id.split())) id = _non_id_at_ends.sub('', id) return str(id) _non_id_chars = re.compile('[^a-z0-9]+') _non_id_at_ends = re.compile('^[-0-9]+|-+$') _non_id_translate = { 0x00f8: u'o', # o with stroke 0x0111: u'd', # d with stroke 0x0127: u'h', # h with stroke 0x0131: u'i', # dotless i 0x0142: u'l', # l with stroke 0x0167: u't', # t with stroke 0x0180: u'b', # b with stroke 0x0183: u'b', # b with topbar 0x0188: u'c', # c with hook 0x018c: u'd', # d with topbar 0x0192: u'f', # f with hook 0x0199: u'k', # k with hook 0x019a: u'l', # l with bar 0x019e: u'n', # n with long right leg 0x01a5: u'p', # p with hook 0x01ab: u't', # t with palatal hook 0x01ad: u't', # t with hook 0x01b4: u'y', # y with hook 0x01b6: u'z', # z with stroke 0x01e5: u'g', # g with stroke 0x0225: u'z', # z with hook 0x0234: u'l', # l with curl 0x0235: u'n', # n with curl 0x0236: u't', # t with curl 0x0237: u'j', # dotless j 0x023c: u'c', # c with stroke 0x023f: u's', # s with swash tail 0x0240: u'z', # z with swash tail 0x0247: u'e', # e with stroke 0x0249: u'j', # j with stroke 0x024b: u'q', # q with hook tail 0x024d: u'r', # r with stroke 0x024f: u'y', # y with stroke } _non_id_translate_digraphs = { 0x00df: u'sz', # ligature sz 0x00e6: u'ae', # ae 0x0153: u'oe', # ligature oe 0x0238: u'db', # db digraph 0x0239: u'qp', # qp digraph } def dupname(node, name): node['dupnames'].append(name) node['names'].remove(name) # Assume that this method is referenced, even though it isn't; we # don't want to throw unnecessary system_messages. node.referenced = 1 def fully_normalize_name(name): """Return a case- and whitespace-normalized name.""" return ' '.join(name.lower().split()) def whitespace_normalize_name(name): """Return a whitespace-normalized name.""" return ' '.join(name.split()) def serial_escape(value): """Escape string values that are elements of a list, for serialization.""" return value.replace('\\', r'\\').replace(' ', r'\ ') def pseudo_quoteattr(value): """Quote attributes for pseudo-xml""" return '"%s"' % value # # # Local Variables: # indent-tabs-mode: nil # sentence-end-double-space: t # fill-column: 78 # End: