Package net.sf.saxon.event

## Class TreeReceiver

- java.lang.Object
- - net.sf.saxon.event.SequenceReceiver
  - - net.sf.saxon.event.TreeReceiver

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

      public class TreeReceiver
      extends SequenceReceiver

  A TreeReceiver acts as a bridge between a SequenceReceiver, which can receive events for constructing any kind of sequence, and an ordinary Receiver, which only handles events relating to the building of trees. To do this, it has to process any items added to the sequence using the append() interface; all other events are passed through unchanged.

  If atomic items are appended to the sequence, then adjacent atomic items are turned in to a text node by converting them to strings and adding a single space as a separator.

  If a document node is appended to the sequence, then the document node is ignored and its children are appended to the sequence.

  If any other node is appended to the sequence, then it is pushed to the result as a sequence of Receiver events, which may involve walking recursively through the contents of a tree.

- - ### Field Summary

    - ### 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
    --- | ---
    `TreeReceiver​(Receiver nextInChain)` | Create a TreeReceiver

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `append​(Item item, Location locationId, int copyNamespaces)` | Append an arbitrary item (node or atomic value) to the output
    `void` | `characters​(java.lang.CharSequence chars, Location locationId, int properties)` | Character data
    `void` | `close()` | End of event sequence
    `void` | `comment​(java.lang.CharSequence chars, Location locationId, int properties)` | Output a comment
    `void` | `endDocument()` | Notify the end of a document node
    `void` | `endElement()` | End of element
    `Receiver` | `getNextReceiver()` | Get the underlying Receiver (that is, the next one in the pipeline)
    `void` | `open()` | Start of event sequence
    `void` | `processingInstruction​(java.lang.String target, java.lang.CharSequence data, Location locationId, int properties)` | Processing Instruction
    `void` | `setPipelineConfiguration​(PipelineConfiguration pipe)` | Set the pipeline configuration
    `void` | `setSystemId​(java.lang.String systemId)` | Set the system ID
    `void` | `setUnparsedEntity​(java.lang.String name, java.lang.String uri, java.lang.String publicId)` | Set the URI for an unparsed entity in the document.
    `void` | `startDocument​(int properties)` | Start of a document node.
    `void` | `startElement​(NodeName elemName, SchemaType type, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties)` | Notify the start of an element
    `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.SequenceReceiver

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

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

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

- - ### Constructor Detail

    - #### TreeReceiver

          public TreeReceiver​(Receiver nextInChain)

      Create a TreeReceiver
      Parameters:
        `nextInChain` - the receiver to which events will be directed, after expanding append events into more primitive tree-based events

  - ### Method Detail

    - #### setSystemId

          public void setSystemId​(java.lang.String systemId)

      Description copied from class: `SequenceReceiver`
      Set the system ID
      Specified by:
        `setSystemId` in interface `Receiver`
      Specified by:
        `setSystemId` in interface `javax.xml.transform.Result`
      Overrides:
        `setSystemId` in class `SequenceReceiver`
      Parameters:
        `systemId` - the URI used to identify the tree being passed across this interface

    - #### setPipelineConfiguration

          public void setPipelineConfiguration​(PipelineConfiguration pipe)

      Description copied from interface: `Receiver`
      Set the pipeline configuration
      Specified by:
        `setPipelineConfiguration` in interface `Receiver`
      Overrides:
        `setPipelineConfiguration` in class `SequenceReceiver`
      Parameters:
        `pipe` - the pipeline configuration

    - #### getNextReceiver

          public Receiver getNextReceiver()

      Get the underlying Receiver (that is, the next one in the pipeline)
      Returns:
        the underlying Receiver

    - #### open

          public void open()
                    throws XPathException

      Start of event sequence
      Specified by:
        `open` in interface `Receiver`
      Overrides:
        `open` in class `SequenceReceiver`
      Throws:
        `XPathException` - if an error occurs

    - #### close

          public void close()
                     throws XPathException

      End of event sequence
      Throws:
        `XPathException` - if an error occurs

    - #### startDocument

          public void startDocument​(int properties)
                             throws XPathException

      Start of a document node.
      Parameters:
        `properties` - bit-significant integer indicating properties of the document node. The definitions of the bits are in class `ReceiverOption`
      Throws:
        `XPathException` - if an error occurs

    - #### endDocument

          public void endDocument()
                           throws XPathException

      Notify the end of a document node
      Throws:
        `XPathException` - if an error occurs

    - #### startElement

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

      Notify the start of an element
      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

      End of element
      Throws:
        `XPathException` - if an error occurs

    - #### characters

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

      Character data
      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
      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
      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

    - #### setUnparsedEntity

          public void setUnparsedEntity​(java.lang.String name,
                                        java.lang.String uri,
                                        java.lang.String publicId)
                                 throws XPathException

      Set the URI for an unparsed entity in the document.
      Specified by:
        `setUnparsedEntity` in interface `Receiver`
      Overrides:
        `setUnparsedEntity` in class `SequenceReceiver`
      Parameters:
        `name` - The name of the unparsed entity
        `uri` - The system identifier of the unparsed entity
        `publicId` - The public identifier of the unparsed entity
      Throws:
        `XPathException` - if an error occurs

    - #### append

          public void append​(Item item,
                             Location locationId,
                             int copyNamespaces)
                      throws XPathException

      Append an arbitrary item (node or atomic value) to the output
      Specified by:
        `append` in interface `Receiver`
      Specified by:
        `append` in class `SequenceReceiver`
      Parameters:
        `item` - the item to be appended
        `locationId` - the location of the calling instruction, for diagnostics
        `copyNamespaces` - if the item is an element node, this indicates whether its namespaces need to be copied. Values are `ReceiverOption.ALL_NAMESPACES`; the default (0) means
      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
      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