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Filters are objects that know how to "filter out" nodes. If an
Iterator or TreeWalker is given a filter, before it
returns the next node, it applies the filter. If the filter says to
accept the node, the Iterator returns it; otherwise, the Iterator
looks for the next node and pretends that the node that was
rejected was not there.
The DOM does not provide any filters. Filter is just an interface that users can implement to provide their own filters.
Filters do not need to know how to iterate, nor do they need to know anything about the data structure that is being iterated. 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 Iterators, encouraging code reuse.
To create your own cutsom NodeFilter, define a subclass of CustomNodeFilter which overrides the acceptNode() method and assign an instance of it to the NodeFilter. For more details see the CustomNodeFilter class
| NodeFilter ()
| NodeFilter |
| NodeFilter (const NodeFilter &other)
| NodeFilter |
| NodeFilter & operator = (const NodeFilter &other)
| operator = |
[virtual]
| ~NodeFilter ()
| ~NodeFilter |
[virtual]
| enum AcceptCode { FILTER_ACCEPT = 1, FILTER_REJECT = 2, FILTER_SKIP = 3 } | AcceptCode |
The following constants are returned by the acceptNode() method:
| enum ShowCode { SHOW_ALL = 0xFFFFFFFF, SHOW_ELEMENT = 0x00000001, SHOW_ATTRIBUTE = 0x00000002, SHOW_TEXT = 0x00000004, SHOW_CDATA_SECTION = 0x00000008, SHOW_ENTITY_REFERENCE = 0x00000010, SHOW_ENTITY = 0x00000020, SHOW_PROCESSING_INSTRUCTION = 0x00000040, SHOW_COMMENT = 0x00000080, SHOW_DOCUMENT = 0x00000100, SHOW_DOCUMENT_TYPE = 0x00000200, SHOW_DOCUMENT_FRAGMENT = 0x00000400, SHOW_NOTATION = 0x00000800 } | ShowCode |
These are the available values for the whatToShow parameter. 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.
| short acceptNode (const Node &n)
| acceptNode |
[virtual]
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 intended to be called directly from user code.
Parameters:
| n | The node to check to see if it passes the filter or not. |
Returns: a constant to determine whether the node is accepted, rejected, or skipped, as defined above .
| NodeFilterImpl * handle ()
| handle |
[const virtual]
not part of the DOM
| bool isNull ()
| isNull |
[const virtual]
| void setCustomNodeFilter (CustomNodeFilter *custom)
| setCustomNodeFilter |
| CustomNodeFilter * customNodeFilter ()
| customNodeFilter |
| NodeFilter createCustom (CustomNodeFilter *custom)
| createCustom |
[static]
| NodeFilter (NodeFilterImpl *i)
| NodeFilter |
[protected]
| NodeFilterImpl * impl | impl |
[protected]
| Generated by: dfaure on faure on Tue Apr 16 08:50:42 2002, using kdoc 2.0a53. |