Package net.sf.saxon.trace

## Class CountingFilter

- java.lang.Object
- - net.sf.saxon.event.SequenceReceiver
  - - net.sf.saxon.event.ProxyReceiver
    - - net.sf.saxon.trace.CountingFilter

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

      public class CountingFilter
      extends ProxyReceiver

  A filter that can be inserted into a Receiver pipeline to count the events that pass through. This class is not normally used in Saxon, but is available for diagnostics when needed. Note that the counters are only maintained if `Instrumentation.ACTIVE` is set to true. The counters can be displayed by calling `Instrumentation.report()`.

- - ### 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
    --- | ---
    `CountingFilter​(Receiver nextReceiver)` | Create a TracingFilter and allocate a unique Id.
    `CountingFilter​(Receiver nextReceiver, java.io.PrintStream diagnosticOutput)` | Create a TracingFilter, allocate a unique Id, and supply the destination for diagnostic trace messages

  - ### 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 document
    `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
    `int` | `getId()` | Get the unique id that was allocated to this TracingFilter
    `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

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

      `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

    - #### CountingFilter

          public CountingFilter​(Receiver nextReceiver)

      Create a TracingFilter and allocate a unique Id.
      Parameters:
        `nextReceiver` - the underlying receiver to which the events will be sent

    - #### CountingFilter

          public CountingFilter​(Receiver nextReceiver,
                                java.io.PrintStream diagnosticOutput)

      Create a TracingFilter, allocate a unique Id, and supply the destination for diagnostic trace messages
      Parameters:
        `nextReceiver` - the underlying receiver to which the events will be sent
        `diagnosticOutput` - the destination for diagnostic trace messages

  - ### Method Detail

    - #### getId

          public int getId()

      Get the unique id that was allocated to this TracingFilter
      Returns:
        the unique id (which is included in all diagnostic messages)

    - #### 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`
      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

    - #### 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

    - #### close

          public void close()
                     throws XPathException

      End of document
      Specified by:
        `close` in interface `Receiver`
      Overrides:
        `close` in class `ProxyReceiver`
      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

    - #### endDocument

          public void endDocument()
                           throws XPathException

      Notify the end of a document node
      Specified by:
        `endDocument` in interface `Receiver`
      Overrides:
        `endDocument` in class `ProxyReceiver`
      Throws:
        `XPathException` - if an error occurs

    - #### endElement

          public void endElement()
                          throws XPathException

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

    - #### open

          public void open()
                    throws XPathException

      Start of event stream
      Specified by:
        `open` in interface `Receiver`
      Overrides:
        `open` in class `ProxyReceiver`
      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

    - #### startDocument

          public void startDocument​(int properties)
                             throws XPathException

      Start of a document node.
      Specified by:
        `startDocument` in interface `Receiver`
      Overrides:
        `startDocument` in class `ProxyReceiver`
      Parameters:
        `properties` -
      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
      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