net.sf.fikin.ant
Class XPathTask

java.lang.Object
  org.apache.tools.ant.ProjectComponent
      org.apache.tools.ant.Task
          net.sf.fikin.ant.XPathTask

public class XPathTask
extends org.apache.tools.ant.Task

Execute XPath expressions against input XML/HTML data and return result.

Support XML or HTML inputs

Support writing to Project properties or a file

Support for multiple xpath expressions per single input

Example:

      <xpath>
          <input file="bin/test/ant/test1/in1.xml" />
          <output property="p1" />
          <forEach select="/root/id" >
              <valueOf select="local-name(..)" />
              <valueOf select="'/'" />
              <valueOf select="local-name()" />
          </forEach>
          <forEach select="/root" >
              <valueOf select="local-name()" />
              <valueOf select="' count nested tags : '" />
              <valueOf select="count(.)" />
          </forEach>
      </xpath>
      <echo>${p1}</echo>
 

where for input file:

      <root><id/></root>
 

would set property p1 to: [echo] root/id root count nested tags : 1

Example:

      <xpath>
          <input>
              <![CDATA[ <root><tag id="1"/><tag id="2"/></root> ]]>
          </input>
          <forEach select="/root/tag" >
              <valueOf select="@id" />
          </forEach>
          <sequential>
              <echo>@{node}</echo>
          </sequential>
      </xpath>
 

would print out: [echo] 1 [echo] 2

created on Jan 3, 2007

Since:

Version:

$Revision: 1.7 $

Author:

fiykov

Ant Task Name:

xpath

Nested Class Summary

class	XPathTask.ForEach Represents a for-each nested tag created on Jan 3, 2007
class	XPathTask.Function Represent a function tag created on Jan 3, 2007
class	XPathTask.ListOfFunctions Functions context handler used by XPath to resolve custom namespaces
class	XPathTask.ListOfNS Namespace context handler used by XPath to resolve custom namespaces
class	XPathTask.Select Represents a value-of nested tag created on Jan 3, 2007

Field Summary

protected FactoryType	factory factory to use, if defined
protected boolean	failOnError abort build when execution error, by default true
protected java.util.Vector	forEachs list of for-each nested tags
protected java.util.Vector	functions hold custom defined functions
protected XHTMLInput	input input document
protected org.apache.tools.ant.taskdefs.MacroDef	macroDef internal instance of MacroDef, corresponds to nested sequential tag
protected org.apache.tools.ant.taskdefs.MacroInstance	macroInstance macro instance used to execute sequential if defined, internal member
protected java.util.Vector	namespaces hold all defined namespaces
protected DelimitedPrintWriter	out output writer, internal member
protected Output	output output document
protected int	recordCnt count how many records were discovered by forEach tags, internal member
protected javax.xml.xpath.XPath	xpath xpath object to use for expression evaluations, internal member
protected javax.xml.xpath.XPathFactory	xpathFactory xpathFactory to use, internal member

Fields inherited from class org.apache.tools.ant.Task

description, location, target, taskName, taskType, wrapper

Fields inherited from class org.apache.tools.ant.ProjectComponent

project

Constructor Summary

XPathTask()

Method Summary

void	addNamespace(Namespace ns) add new namespace tag
void	check(org.apache.tools.ant.Task task) test for input has been set and is consistent test output or sequential has been set and is consistent test namespaces are consistent test functions are consistent test for at least one for-each and it is consistent test factory if defined
protected void	closeOut() close the output system : in this case closing out stream if such has been used (and not macroInstance)
FactoryType	createFactory() create factory tag
XPathTask.ForEach	createForEach() create new for-each tag
XPathTask.Function	createFunction() create new function tag
XHTMLInput	createInput() create xml/html/xhtml input tag
Output	createOutput() create output tag
java.lang.Object	createSequential() Create sequential task
void	execute() execute the task
protected void	execute(org.w3c.dom.Node node, java.util.List selects, java.lang.StringBuffer appendTo) execute xpath for each of Select elements in the vector
protected void	execute(org.w3c.dom.Node node, XPathTask.ForEach fe) execute xpath expression of this for-each
protected void	execute(org.w3c.dom.Node node, XPathTask.Select select, java.lang.StringBuffer appendTo) execute the xpath expression and append it to the string buffer
protected void	execute(java.lang.String rowOfData) either print the data to the output or execute the sequential with it
protected void	initOut() Initialize the output system : this being out stream or macroInstance
protected javax.xml.xpath.XPathFactory	newXPathFactory() instantiate new xpath factory
void	setFailOnError(boolean failOnError) abort build whenever execution error
protected void	setFunctions() set functions the the xpath object
protected void	setNamespaces() set namespaces the the xpath object

Methods inherited from class org.apache.tools.ant.Task

getDescription, getLocation, getOwningTarget, getRuntimeConfigurableWrapper, getTaskName, getTaskType, getWrapper, handleErrorFlush, handleErrorOutput, handleFlush, handleInput, handleOutput, init, isInvalid, log, log, maybeConfigure, perform, reconfigure, setDescription, setLocation, setOwningTarget, setRuntimeConfigurableWrapper, setTaskName, setTaskType

Methods inherited from class org.apache.tools.ant.ProjectComponent

getProject, setProject

Methods inherited from class java.lang.Object

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

Field Detail

failOnError

protected boolean failOnError

abort build when execution error, by default true

namespaces

protected java.util.Vector namespaces

hold all defined namespaces

functions

protected java.util.Vector functions

hold custom defined functions

macroDef

protected org.apache.tools.ant.taskdefs.MacroDef macroDef

internal instance of MacroDef, corresponds to nested sequential tag

input

protected XHTMLInput input

input document

output

protected Output output

output document

forEachs

protected java.util.Vector forEachs

list of for-each nested tags

factory

protected FactoryType factory

factory to use, if defined

xpathFactory

protected javax.xml.xpath.XPathFactory xpathFactory

xpathFactory to use, internal member

xpath

protected javax.xml.xpath.XPath xpath

xpath object to use for expression evaluations, internal member

out

protected DelimitedPrintWriter out

output writer, internal member

macroInstance

protected org.apache.tools.ant.taskdefs.MacroInstance macroInstance

macro instance used to execute sequential if defined, internal member

recordCnt

protected int recordCnt

count how many records were discovered by forEach tags, internal member

Constructor Detail

XPathTask

public XPathTask()

Method Detail

setFailOnError

public void setFailOnError(boolean failOnError)

abort build whenever execution error

Parameters:

failOnError - aborts build if set to true,

by default true

Ant Task Param Required:

false

addNamespace

public void addNamespace(Namespace ns)

add new namespace tag

Parameters:

ns - is a new namespace tag

Ant Task Param Required:

false

createFunction

public XPathTask.Function createFunction()

create new function tag

Returns:

new function

Ant Task Param Required:

false

createInput

public XHTMLInput createInput()

create xml/html/xhtml input tag

Returns:

XHTMLInput is the input for the DOM tree creation

Ant Task Param Required:

true

createSequential

public java.lang.Object createSequential()

Create sequential task

Its code will be executed for each Node found in by for-each tags

One can refer to the combined value-of string (computed for that Node) via the macro attribute @{node}

Returns:

a MacroDef#NestedSequential object to be configured

Ant Task Param Required:

this or a sequential tag is expected

createOutput

public Output createOutput()

create output tag

Returns:

Output is the output of the XPath expression evaluation, a file or property

Ant Task Param Required:

this or a sequential tag is expected

createFactory

public FactoryType createFactory()

create factory tag

Returns:

XPathFactory to use

Ant Task Param Required:

false

createForEach

public XPathTask.ForEach createForEach()

create new for-each tag

Returns:

foreach is a new for-each tag

Ant Task Param Required:

true

check

public void check(org.apache.tools.ant.Task task)
           throws org.apache.tools.ant.BuildException

test for input has been set and is consistent test output or sequential has been set and is consistent test namespaces are consistent test functions are consistent test for at least one for-each and it is consistent test factory if defined

Throws:

org.apache.tools.ant.BuildException

execute

public void execute()
             throws org.apache.tools.ant.BuildException

execute the task

Overrides:

execute in class org.apache.tools.ant.Task

Throws:

org.apache.tools.ant.BuildException

execute

protected void execute(org.w3c.dom.Node node,
                       XPathTask.ForEach fe)
                throws org.apache.tools.ant.BuildException

execute xpath expression of this for-each

Parameters:

node - to use as root

fe - is for-each xpath expression

Throws:

org.apache.tools.ant.BuildException

execute

protected void execute(org.w3c.dom.Node node,
                       java.util.List selects,
                       java.lang.StringBuffer appendTo)
                throws javax.xml.xpath.XPathExpressionException

execute xpath for each of Select elements in the vector

Parameters:

node - to use as base

selects - is a list of

appendTo - is a string buffer to append the evaluation result to

Throws:

javax.xml.xpath.XPathExpressionException

execute

protected void execute(org.w3c.dom.Node node,
                       XPathTask.Select select,
                       java.lang.StringBuffer appendTo)
                throws javax.xml.xpath.XPathExpressionException

execute the xpath expression and append it to the string buffer

Parameters:

node - to use as base

select - is xpath to evaluate

appendTo - is a string buffer to append the evaluation result to

Throws:

javax.xml.xpath.XPathExpressionException

execute

protected void execute(java.lang.String rowOfData)

either print the data to the output or execute the sequential with it

Parameters:

rowOfData -

initOut

protected void initOut()

Initialize the output system : this being out stream or macroInstance

To be called once before calling execute(String) for first time

closeOut

protected void closeOut()

close the output system : in this case closing out stream if such has been used (and not macroInstance)

To be called at the end of the task execution i.e. execute()

newXPathFactory

protected javax.xml.xpath.XPathFactory newXPathFactory()
                                                throws org.apache.tools.ant.BuildException

instantiate new xpath factory

Returns:

XPathFactory.newInstance()

Throws:

org.apache.tools.ant.BuildException

setNamespaces

protected void setNamespaces()

set namespaces the the xpath object

setFunctions

protected void setFunctions()

set functions the the xpath object