Package org.apache.beam.sdk.transforms.display

Class DisplayData.Item

java.lang.Object
org.apache.beam.sdk.transforms.display.DisplayData.Item
All Implemented Interfaces:
Serializable
Enclosing class:
DisplayData
public abstract static class DisplayData.Item extends Object implements 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:

  • Constructor Details

    • Item

      public Item()

  • Method Details

    • getPath

      public abstract @Nullable DisplayData.Path getPath()
      The path for the display item within a component hierarchy.

    • getNamespace

      public abstract @Nullable Class<?> getNamespace()
      The namespace for the display item. The namespace defaults to the component which the display item belongs to.

    • getKey

      public abstract 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 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 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 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 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 String toString()
      Overrides:
      toString in class Object