| import gettext |
| _ = gettext.gettext |
| |
| import _base |
| |
| class TreeWalker(_base.NonRecursiveTreeWalker): |
| """Given that simpletree has no performant way of getting a node's |
| next sibling, this implementation returns "nodes" as tuples with the |
| following content: |
| |
| 1. The parent Node (Element, Document or DocumentFragment) |
| |
| 2. The child index of the current node in its parent's children list |
| |
| 3. A list used as a stack of all ancestors. It is a pair tuple whose |
| first item is a parent Node and second item is a child index. |
| """ |
| |
| def getNodeDetails(self, node): |
| if isinstance(node, tuple): # It might be the root Node |
| parent, idx, parents = node |
| node = parent.childNodes[idx] |
| |
| # testing node.type allows us not to import treebuilders.simpletree |
| if node.type in (1, 2): # Document or DocumentFragment |
| return (_base.DOCUMENT,) |
| |
| elif node.type == 3: # DocumentType |
| return _base.DOCTYPE, node.name, node.publicId, node.systemId |
| |
| elif node.type == 4: # TextNode |
| return _base.TEXT, node.value |
| |
| elif node.type == 5: # Element |
| attrs = {} |
| for name, value in node.attributes.items(): |
| if isinstance(name, tuple): |
| attrs[(name[2],name[1])] = value |
| else: |
| attrs[(None,name)] = value |
| return (_base.ELEMENT, node.namespace, node.name, |
| attrs, node.hasContent()) |
| |
| elif node.type == 6: # CommentNode |
| return _base.COMMENT, node.data |
| |
| else: |
| return _node.UNKNOWN, node.type |
| |
| def getFirstChild(self, node): |
| if isinstance(node, tuple): # It might be the root Node |
| parent, idx, parents = node |
| parents.append((parent, idx)) |
| node = parent.childNodes[idx] |
| else: |
| parents = [] |
| |
| assert node.hasContent(), "Node has no children" |
| return (node, 0, parents) |
| |
| def getNextSibling(self, node): |
| assert isinstance(node, tuple), "Node is not a tuple: " + str(node) |
| parent, idx, parents = node |
| idx += 1 |
| if len(parent.childNodes) > idx: |
| return (parent, idx, parents) |
| else: |
| return None |
| |
| def getParentNode(self, node): |
| assert isinstance(node, tuple) |
| parent, idx, parents = node |
| if parents: |
| parent, idx = parents.pop() |
| return parent, idx, parents |
| else: |
| # HACK: We could return ``parent`` but None will stop the algorithm the same way |
| return None |
