datafu.pig.util
Class ContextualEvalFunc<T>

java.lang.Object
  org.apache.pig.EvalFunc<T>
      datafu.pig.util.ContextualEvalFunc<T>

Type Parameters:

T -

Direct Known Subclasses:

AliasableEvalFunc, EmptyBagToNullFields

public abstract class ContextualEvalFunc<T>
extends org.apache.pig.EvalFunc<T>

An abstract class which enables UDFs to store instance properties on the front end which will be available on the back end. For example, properties may be set in the call to outputSchema(), which will be available when exec() is called.

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

ContextualEvalFunc()

Method Summary

protected java.util.Properties	getContextProperties() Helper method to return the context properties for this class
protected java.lang.String	getInstanceName()
protected java.util.Properties	getInstanceProperties() Helper method to return the context properties for this instance of this class
void	setUDFContextSignature(java.lang.String signature)

Methods inherited from class org.apache.pig.EvalFunc

exec, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, isAsynchronous, outputSchema, progress, setInputSchema, setPigLogger, setReporter, warn

Methods inherited from class java.lang.Object

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

Constructor Detail

ContextualEvalFunc

public ContextualEvalFunc()

Method Detail

setUDFContextSignature

public void setUDFContextSignature(java.lang.String signature)

Overrides:

setUDFContextSignature in class org.apache.pig.EvalFunc<T>

getContextProperties

protected java.util.Properties getContextProperties()

Helper method to return the context properties for this class

Returns:

context properties

getInstanceProperties

protected java.util.Properties getInstanceProperties()

Helper method to return the context properties for this instance of this class

Returns:

instances properties

getInstanceName

protected java.lang.String getInstanceName()

Returns:

the name of this instance corresponding to the UDF Context Signature

See Also:

setUDFContextSignature(String)