Package net.sf.saxon.serialize

## Class PrincipalOutputGatekeeper

- java.lang.Object
- - net.sf.saxon.event.SequenceReceiver
  - - net.sf.saxon.event.ProxyReceiver
    - - net.sf.saxon.serialize.PrincipalOutputGatekeeper

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

      public class PrincipalOutputGatekeeper
      extends ProxyReceiver

  This class is added to the output pipeline for the principal result destination for a transformation if the transformation uses xsl:result-document instructions. It is there to deal with the possibility that an xsl:result-document instruction will use the same output URI (or no output URI) in which case it is defined to write to the principal output destination, but potentially with different serialization parameters.

  If actual output is produced to the principal result destination, then this `PrincipalOutputGatekeeper` will be marked as being "used by primary", which will cause any attempt to open a secondary result destination on the same URI (either explicitly, or by omitting the `href` attribute, or by setting `href` to a zero length string) as an error. Apart from this marker, the `PrincipalOutputGatekeeper` acts as a pass-through filter for the output events.

  If a secondary result destination is opened using the principal output URI (either explicitly or implicitly), then the `PrincipalOutputGatekeeper` is marked as being "used by secondary", which will cause any attempts to write events to the `PrincipalOutputGatekeeper` to fail. Secondary result output is not actually directed through the gatekeeper; the gatekeeper is merely notified of its existence.

- - ### 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
    --- | ---
    `PrincipalOutputGatekeeper​(XsltController controller, Receiver next)` |

  - ### 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 output.
    `void` | `comment​(java.lang.CharSequence chars, Location locationId, int properties)` | Output a comment
    `Receiver` | `makeReceiver​(SerializationProperties params)` |
    `void` | `open()` | Start of event stream
    `void` | `processingInstruction​(java.lang.String target, java.lang.CharSequence data, Location locationId, int properties)` | Processing Instruction
    `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
    `void` | `useAsSecondary()` |

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

      `endDocument, endElement, getNamePool, getNextReceiver, setPipelineConfiguration, setSystemId, setUnderlyingReceiver, setUnparsedEntity, usesTypeAnnotations`

    - ### 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

    - #### PrincipalOutputGatekeeper

          public PrincipalOutputGatekeeper​(XsltController controller,
                                           Receiver next)

  - ### Method Detail

    - #### open

          public void open()
                    throws XPathException

      Description copied from class: `ProxyReceiver`
      Start of event stream
      Specified by:
        `open` in interface `Receiver`
      Overrides:
        `open` in class `ProxyReceiver`
      Throws:
        `XPathException` - if an error occurs

    - #### startDocument

          public void startDocument​(int properties)
                             throws XPathException

      Description copied from class: `ProxyReceiver`
      Start of a document node.
      Specified by:
        `startDocument` in interface `Receiver`
      Overrides:
        `startDocument` in class `ProxyReceiver`
      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

    - #### startElement

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

      Description copied from class: `ProxyReceiver`
      Notify the start of an element
      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

    - #### characters

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

      Description copied from class: `ProxyReceiver`
      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

      Description copied from class: `ProxyReceiver`
      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

      Description copied from class: `ProxyReceiver`
      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

    - #### append

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

      Description copied from class: `ProxyReceiver`
      Append an arbitrary item (node or atomic value) to the output
      Specified by:
        `append` in interface `Receiver`
      Overrides:
        `append` in class `ProxyReceiver`
      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

    - #### useAsSecondary

          public void useAsSecondary()
                              throws XPathException

      Throws:
        `XPathException`

    - #### makeReceiver

          public Receiver makeReceiver​(SerializationProperties params)

    - #### close

          public void close()
                     throws XPathException

      Description copied from class: `ProxyReceiver`
      End of output. Note that closing this receiver also closes the rest of the pipeline.
      Specified by:
        `close` in interface `Receiver`
      Overrides:
        `close` in class `ProxyReceiver`
      Throws:
        `XPathException` - if an error occurs