topical media & game development
lib-of-vs-libs-Poco-include-Poco-DOM-NodeFilter.h / h
//
// NodeFilter.h
//
//
//
// Library: XML
// Package: DOM
// Module: NodeFilter
//
// Definition of the DOM NodeFilter interface.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef DOM_NodeFilter_INCLUDED
define DOM_NodeFilter_INCLUDED
include "Poco/XML/XML.h"
include "Poco/XML/XMLString.h"
namespace Poco {
namespace XML {
class Node;
class XML_API NodeFilter
Filters are objects that know how to "filter out" nodes. If a NodeIterator
or TreeWalker is given a NodeFilter, it applies the filter before it returns
the next node. If the filter says to accept the node, the traversal logic
returns it; otherwise, traversal looks for the next node and pretends that
the node that was rejected was not there.
The DOM does not provide any filters. NodeFilter is just an interface that
users can implement to provide their own filters.
NodeFilters do not need to know how to traverse from node to node, nor do
they need to know anything about the data structure that is being traversed.
This makes it very easy to write filters, since the only thing they have
to know how to do is evaluate a single node. One filter may be used with
a number of different kinds of traversals, encouraging code reuse.
{
public:
enum
{
FILTER_ACCEPT = 1,
Accept the node. Navigation methods defined for NodeIterator or TreeWalker will return this node.
FILTER_REJECT = 2,
Reject the node. Navigation methods defined for NodeIterator or TreeWalker
will not return this node. For TreeWalker, the children of this node will
also be rejected. NodeIterators treat this as a synonym for FILTER_SKIP.
FILTER_SKIP = 3
Skip this single node. Navigation methods defined for NodeIterator or TreeWalker
will not return this node. For both NodeIterator and TreeWalker, the children
of this node will still be considered.
};
enum WhatToShow
These are the available values for the whatToShow parameter used in TreeWalkers
and NodeIterators. They are the same as the set of possible types for Node,
and their values are derived by using a bit position corresponding to the
value of nodeType for the equivalent node type. If a bit in whatToShow is
set false, that will be taken as a request to skip over this type of node;
the behavior in that case is similar to that of FILTER_SKIP.
Note that if node types greater than 32 are ever introduced, they may not
be individually testable via whatToShow. If that need should arise, it can
be handled by selecting SHOW_ALL together with an appropriate NodeFilter.
{
SHOW_ALL = 0xFFFFFFFF,
Show all Nodes.
SHOW_ELEMENT = 0x00000001,
Show Element nodes.
SHOW_ATTRIBUTE = 0x00000002,
Show Attr nodes. This is meaningful only when creating an iterator or tree-walker
with an attribute node as its root; in this case, it means that the attribute
node will appear in the first position of the iteration or traversal. Since
attributes are never children of other nodes, they do not appear when traversing
over the document tree.
SHOW_TEXT = 0x00000004,
Show
Text nodes.
SHOW_CDATA_SECTION = 0x00000008,
Show CDATASection nodes.
SHOW_ENTITY_REFERENCE = 0x00000010,
Show EntityReference nodes.
SHOW_ENTITY = 0x00000020,
Show Entity nodes. This is meaningful only when creating an iterator or
tree-walker with an Entity node as its root; in this case, it means that
the Entity node will appear in the first position of the traversal. Since
entities are not part of the document tree, they do not appear when traversing
over the document tree.
SHOW_PROCESSING_INSTRUCTION = 0x00000040,
Show ProcessingInstruction nodes.
SHOW_COMMENT = 0x00000080,
Show Comment nodes.
SHOW_DOCUMENT = 0x00000100,
Show Document nodes.
SHOW_DOCUMENT_TYPE = 0x00000200,
Show DocumentType nodes.
SHOW_DOCUMENT_FRAGMENT = 0x00000400,
Show DocumentFragment nodes.
SHOW_NOTATION = 0x00000800
Show Notation nodes. This is meaningful only when creating an iterator or
tree-walker with a Notation node as its root; in this case, it means that
the Notation node will appear in the first position of the traversal. Since
notations are not part of the document tree, they do not appear when traversing
over the document tree.
};
virtual short acceptNode(Node* node) = 0;
Test whether a specified node is visible in the logical view of a TreeWalker
or NodeIterator. This function will be called by the implementation of TreeWalker
and NodeIterator; it is not normally called directly from user code. (Though
you could do so if you wanted to use the same filter to guide your own application
logic.)
Returns FILTER_ACCEPT, FILTER_REJECT or FILTER_SKIP.
protected:
virtual ~NodeFilter();
};
} } // namespace Poco::XML
endif // DOM_NodeFilter_INCLUDED
(C) Æliens
04/09/2009
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