Package net.sf.saxon.event

## Class IDFilter

- java.lang.Object
- - net.sf.saxon.event.SequenceReceiver
  - - net.sf.saxon.event.ProxyReceiver
    - - net.sf.saxon.event.IDFilter

- All Implemented Interfaces:
    `javax.xml.transform.Result`, `Receiver`

      public class IDFilter
      extends ProxyReceiver

  IDFilter is a ProxyReceiver that extracts the subtree of a document rooted at the element with a given ID value. Namespace declarations outside this subtree are treated as if they were present on the identified element.

  Note, this class only looks for ID attributes, not for ID elements.

- - ### Field Summary

    - ### Fields inherited from class net.sf.saxon.event.ProxyReceiver

      `nextReceiver`

    - ### Fields inherited from class net.sf.saxon.event.SequenceReceiver

      `pipelineConfiguration, previousAtomic, systemId`

    - ### Fields inherited from interface javax.xml.transform.Result

      `PI_DISABLE_OUTPUT_ESCAPING, PI_ENABLE_OUTPUT_ESCAPING`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `IDFilter​(Receiver next, java.lang.String id)` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `characters​(java.lang.CharSequence chars, Location locationId, int properties)` | Character data
    `void` | `comment​(java.lang.CharSequence chars, Location locationId, int properties)` | Output a comment
    `void` | `endElement()` | endElement:
    `void` | `processingInstruction​(java.lang.String target, java.lang.CharSequence data, Location locationId, int properties)` | Processing Instruction
    `void` | `startElement​(NodeName elemName, SchemaType type, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties)` | startElement
    `boolean` | `usesTypeAnnotations()` | Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events

    - ### Methods inherited from class net.sf.saxon.event.ProxyReceiver

      `append, close, endDocument, getNamePool, getNextReceiver, open, setPipelineConfiguration, setSystemId, setUnderlyingReceiver, setUnparsedEntity, startDocument`

    - ### Methods inherited from class net.sf.saxon.event.SequenceReceiver

      `append, decompose, flatten, getConfiguration, getErrorCodeForDecomposingFunctionItems, getPipelineConfiguration, getSystemId, handlesAppend`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### IDFilter

          public IDFilter​(Receiver next,
                          java.lang.String id)

  - ### Method Detail

    - #### startElement

          public void startElement​(NodeName elemName,
                                   SchemaType type,
                                   AttributeMap attributes,
                                   NamespaceMap namespaces,
                                   Location location,
                                   int properties)
                            throws XPathException

      startElement
      Specified by:
        `startElement` in interface `Receiver`
      Overrides:
        `startElement` in class `ProxyReceiver`
      Parameters:
        `elemName` - the name of the element.
        `type` - the type annotation of the element.
        `attributes` - the attributes of this element
        `namespaces` - the in-scope namespaces of this element: generally this is all the in-scope namespaces, without relying on inheriting namespaces from parent elements
        `location` - an object providing information about the module, line, and column where the node originated
        `properties` - bit-significant properties of the element node. If there are no relevant properties, zero is supplied. The definitions of the bits are in class `ReceiverOption`
      Throws:
        `XPathException` - if an error occurs

    - #### endElement

          public void endElement()
                          throws XPathException

      endElement:
      Specified by:
        `endElement` in interface `Receiver`
      Overrides:
        `endElement` in class `ProxyReceiver`
      Throws:
        `XPathException` - if an error occurs

    - #### characters

          public void characters​(java.lang.CharSequence chars,
                                 Location locationId,
                                 int properties)
                          throws XPathException

      Character data
      Specified by:
        `characters` in interface `Receiver`
      Overrides:
        `characters` in class `ProxyReceiver`
      Parameters:
        `chars` - The characters
        `locationId` - provides information such as line number and system ID.
        `properties` - Bit significant value. The following bits are defined:
        DISABLE_ESCAPING
          Disable escaping for this text node
        USE_CDATA
          Output as a CDATA section
      Throws:
        `XPathException` - if an error occurs

    - #### processingInstruction

          public void processingInstruction​(java.lang.String target,
                                            java.lang.CharSequence data,
                                            Location locationId,
                                            int properties)
                                     throws XPathException

      Processing Instruction
      Specified by:
        `processingInstruction` in interface `Receiver`
      Overrides:
        `processingInstruction` in class `ProxyReceiver`
      Parameters:
        `target` - The PI name. This must be a legal name (it will not be checked).
        `data` - The data portion of the processing instruction
        `locationId` - provides information such as line number and system ID.
        `properties` - Additional information about the PI.
      Throws:
        `XPathException` - if an error occurs

    - #### comment

          public void comment​(java.lang.CharSequence chars,
                              Location locationId,
                              int properties)
                       throws XPathException

      Output a comment
      Specified by:
        `comment` in interface `Receiver`
      Overrides:
        `comment` in class `ProxyReceiver`
      Parameters:
        `chars` - The content of the comment
        `locationId` - provides information such as line number and system ID.
        `properties` - Additional information about the comment.
      Throws:
        `XPathException` - if an error occurs

    - #### usesTypeAnnotations

          public boolean usesTypeAnnotations()

      Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events
      Specified by:
        `usesTypeAnnotations` in interface `Receiver`
      Overrides:
        `usesTypeAnnotations` in class `ProxyReceiver`
      Returns:
        true if the Receiver makes any use of this information. If false, the caller may supply untyped nodes instead of supplying the type annotation