cascading.operation.xml
Class XPathParser

java.lang.Object
  cascading.operation.BaseOperation<cascading.util.Pair<DocumentBuilder,Tuple>>
      cascading.operation.xml.XPathOperation
          cascading.operation.xml.XPathParser

All Implemented Interfaces:

Function<cascading.util.Pair<DocumentBuilder,Tuple>>, Operation<cascading.util.Pair<DocumentBuilder,Tuple>>, Serializable

public class XPathParser
extends XPathOperation
implements Function<cascading.util.Pair<DocumentBuilder,Tuple>>

XPathParser will extract a value from the passed Tuple argument into a new Tuple field. One field for every given XPath expression will be created. This function effectively converts an XML document into a table.

If the returned value of the expression is a NodeList, only the first Node is used. The Node is converted to a new XML document and converted to a String. If only the text values are required, search on the text() nodes, or consider using XPathGenerator to handle multiple NodeList values.

See Also:

Serialized Form

Field Summary

Fields inherited from class cascading.operation.xml.XPathOperation

NAMESPACE_XHTML, namespaces, paths

Fields inherited from class cascading.operation.BaseOperation

fieldDeclaration, numArgs, trace

Fields inherited from interface cascading.operation.Operation

ANY

Constructor Summary

XPathParser(Fields fieldDeclaration, String... paths)
Constructor XPathParser creates a new XPathParser instance.

XPathParser(Fields fieldDeclaration, String[][] namespaces, String... paths)
Constructor XPathParser creates a new XPathParser instance.

Method Summary

void	operate(FlowProcess flowProcess, FunctionCall<cascading.util.Pair<DocumentBuilder,Tuple>> functionCall) Method operate provides the implementation of this Function.

Methods inherited from class cascading.operation.xml.XPathOperation

equals, getExpressions, getTransformer, getXPath, hashCode, parseDocument, prepare, writeAsXML

Methods inherited from class cascading.operation.BaseOperation

cleanup, flush, getFieldDeclaration, getNumArgs, getTrace, isSafe, printOperationInternal, toString, toStringInternal

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface cascading.operation.Operation

cleanup, flush, getFieldDeclaration, getNumArgs, isSafe, prepare

Constructor Detail

XPathParser

public XPathParser(Fields fieldDeclaration,
                   String[][] namespaces,
                   String... paths)

Constructor XPathParser creates a new XPathParser instance.

Parameters:

fieldDeclaration - of type Fields

namespaces - of type String[][]

paths - of type String...

XPathParser

public XPathParser(Fields fieldDeclaration,
                   String... paths)

Constructor XPathParser creates a new XPathParser instance.

Parameters:

fieldDeclaration - of type Fields

paths - of type String...

Method Detail

operate

public void operate(FlowProcess flowProcess,
                    FunctionCall<cascading.util.Pair<DocumentBuilder,Tuple>> functionCall)

Description copied from interface: Function

Method operate provides the implementation of this Function.

Specified by:

operate in interface Function<cascading.util.Pair<DocumentBuilder,Tuple>>

Parameters:

flowProcess - of type FlowProcess

functionCall - of type FunctionCall