org.apache.beam.sdk.util.construction

Class ForwardingPTransform<InputT extends PInput,OutputT extends POutput>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<InputT,OutputT>

org.apache.beam.sdk.util.construction.ForwardingPTransform<InputT,OutputT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

public abstract class ForwardingPTransform<InputT extends PInput,OutputT extends POutput>
extends PTransform<InputT,OutputT>

A base class for implementing PTransform overrides, which behave identically to the delegate transform but with overridden methods. Implementors are required to implement delegate(), which returns the object to forward calls to, and expand(PInput).

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

annotations, displayData, name, resourceHints

Constructor Summary

Constructors

Constructor and Description
ForwardingPTransform()

Method Summary

Modifier and Type	Method and Description
protected abstract PTransform<InputT,OutputT>	delegate()
OutputT	expand(InputT input) Override this method to specify how this PTransform should be expanded on the given InputT.
java.util.Map<TupleTag<?>,PValue>	getAdditionalInputs() Returns all PValues that are consumed as inputs to this PTransform that are independent of the expansion of the InputT within PTransform.expand(PInput).
java.lang.String	getName() Returns the transform name.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
void	validate(PipelineOptions options) Called before running the Pipeline to verify this transform is fully and correctly specified.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

addAnnotation, compose, compose, getAnnotations, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getResourceHints, setDisplayData, setResourceHints, toString, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

ForwardingPTransform

public ForwardingPTransform()

Method Detail

delegate

protected abstract PTransform<InputT,OutputT> delegate()

expand

public OutputT expand(InputT input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<InputT extends PInput,OutputT extends POutput>

getAdditionalInputs

public java.util.Map<TupleTag<?>,PValue> getAdditionalInputs()

Description copied from class: PTransform

Returns all PValues that are consumed as inputs to this PTransform that are independent of the expansion of the InputT within PTransform.expand(PInput).

For example, this can contain any side input consumed by this PTransform.

Overrides:

getAdditionalInputs in class PTransform<InputT extends PInput,OutputT extends POutput>

validate

public void validate(PipelineOptions options)

Description copied from class: PTransform

Called before running the Pipeline to verify this transform is fully and correctly specified.

By default, does nothing.

Overrides:

validate in class PTransform<InputT extends PInput,OutputT extends POutput>

getName

public java.lang.String getName()

Description copied from class: PTransform

Returns the transform name.

This name is provided by the transform creator and is not required to be unique.

Overrides:

getName in class PTransform<InputT extends PInput,OutputT extends POutput>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<InputT extends PInput,OutputT extends POutput>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData