org.apache.beam.sdk.transforms.display

Class DisplayData.ItemSpec<T>

java.lang.Object

org.apache.beam.sdk.transforms.display.DisplayData.ItemSpec<T>

All Implemented Interfaces:

java.io.Serializable

Enclosing class:

DisplayData

public abstract static class DisplayData.ItemSpec<T>
extends java.lang.Object
implements java.io.Serializable

Specifies an DisplayData.Item to register as display data. Each item is identified by a given path, key, and namespace from the component the display item belongs to.

Items are registered via DisplayData.Builder.add(org.apache.beam.sdk.transforms.display.DisplayData.ItemSpec<?>) within HasDisplayData.populateDisplayData(org.apache.beam.sdk.transforms.display.DisplayData.Builder) implementations.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ItemSpec()

Method Summary

Modifier and Type	Method and Description
abstract java.lang.String	getKey() The key for the display item.
abstract @Nullable java.lang.String	getLabel() The optional label for an item.
abstract @Nullable java.lang.String	getLinkUrl() The optional link URL for an item.
abstract @Nullable java.lang.Class<?>	getNamespace() The namespace for the display item.
abstract @Nullable java.lang.Object	getShortValue() The optional short value for an item, or null if none is provided.
abstract DisplayData.Type	getType() The DisplayData.Type of display data.
abstract @Nullable java.lang.Object	getValue() The value of the display item.
java.lang.String	toString()
DisplayData.ItemSpec<T>	withLabel(@Nullable java.lang.String label) Set the item label.
DisplayData.ItemSpec<T>	withLinkUrl(@Nullable java.lang.String url) Set the item link url.
DisplayData.ItemSpec<T>	withNamespace(java.lang.Class<?> namespace) Set the item namespace from the given Class.

Methods inherited from class java.lang.Object

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

Constructor Detail

ItemSpec

public ItemSpec()

Method Detail

getNamespace

public abstract @Nullable java.lang.Class<?> getNamespace()

The namespace for the display item. If unset, defaults to the component which the display item is registered to.

getKey

public abstract java.lang.String getKey()

The key for the display item. Each display item is created with a key and value via DisplayData.item(java.lang.String, java.lang.String).

getType

public abstract DisplayData.Type getType()

The DisplayData.Type of display data. All display data conforms to a predefined set of allowed types.

getValue

public abstract @Nullable java.lang.Object getValue()

The value of the display item. The value is translated from the input to DisplayData.item(java.lang.String, java.lang.String) into a format suitable for display. Translation is based on the item's type.

getShortValue

public abstract @Nullable java.lang.Object getShortValue()

The optional short value for an item, or null if none is provided.

The short value is an alternative display representation for items having a long display value. For example, the value for DisplayData.Type.JAVA_CLASS items contains the full class name with package, while the short value contains just the class name.

A value will be provided for each display item, and some types may also provide a short-value. If a short value is provided, display data consumers may choose to display it instead of or in addition to the value.

getLabel

public abstract @Nullable java.lang.String getLabel()

The optional label for an item. The label is a human-readable description of what the metadata represents. UIs may choose to display the label instead of the item key.

getLinkUrl

public abstract @Nullable java.lang.String getLinkUrl()

The optional link URL for an item. The URL points to an address where the reader can find additional context for the display data.

withNamespace

public DisplayData.ItemSpec<T> withNamespace(java.lang.Class<?> namespace)

Set the item namespace from the given Class.

This method does not alter the current instance, but instead returns a new DisplayData.ItemSpec with the namespace set.

withLabel

public DisplayData.ItemSpec<T> withLabel(@Nullable java.lang.String label)

Set the item label.

Specifying a null value will clear the label if it was previously defined.

This method does not alter the current instance, but instead returns a new DisplayData.ItemSpec with the label set.

withLinkUrl

public DisplayData.ItemSpec<T> withLinkUrl(@Nullable java.lang.String url)

Set the item link url.

Specifying a null value will clear the link url if it was previously defined.

This method does not alter the current instance, but instead returns a new DisplayData.ItemSpec with the link url set.

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object