org.apache.beam.sdk.transforms.display

Class DisplayData.Item

java.lang.Object

org.apache.beam.sdk.transforms.display.DisplayData.Item

All Implemented Interfaces:

java.io.Serializable

Enclosing class:

DisplayData

public abstract static class DisplayData.Item
extends java.lang.Object
implements java.io.Serializable

Items are the unit of 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
Item()

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() Retrieve the optional label for an item.
abstract @Nullable java.lang.String	getLinkUrl() Retrieve the optional link URL for an item.
abstract @Nullable java.lang.Class<?>	getNamespace() The namespace for the display item.
abstract @Nullable DisplayData.Path	getPath() The path for the display item within a component hierarchy.
abstract @Nullable java.lang.Object	getShortValue() Return the optional short value for an item, or null if none is provided.
abstract DisplayData.Type	getType() Retrieve the DisplayData.Type of display data.
abstract @Nullable java.lang.Object	getValue() Retrieve the value of the display item.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Item

public Item()

Method Detail

getPath

public abstract @Nullable DisplayData.Path getPath()

The path for the display item within a component hierarchy.

getNamespace

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

The namespace for the display item. The namespace defaults to the component which the display item belongs 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()

Retrieve the DisplayData.Type of display data. All metadata conforms to a predefined set of allowed types.

getValue

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

Retrieve 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()

Return 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()

Retrieve 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.

If no label was specified, this will return null.

getLinkUrl

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

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

If no URL was specified, this will return null.

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object