public abstract static class DisplayData.Item<T> extends Object implements Serializable
Items are the unit of display data. Each item is identified by a given 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.Item<?>)
within HasDisplayData.populateDisplayData(org.apache.beam.sdk.transforms.display.DisplayData.Builder) implementations.
| Constructor and Description |
|---|
Item() |
| Modifier and Type | Method and Description |
|---|---|
abstract String |
getKey()
The key for the display item.
|
abstract String |
getLabel()
Retrieve the optional label for an item.
|
abstract String |
getLinkUrl()
Retrieve the optional link URL for an item.
|
abstract String |
getNamespace()
The namespace for the display item.
|
abstract 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 Object |
getValue()
Retrieve the value of the display item.
|
String |
toString() |
DisplayData.Item<T> |
withLabel(String label)
Set the item
label. |
DisplayData.Item<T> |
withLinkUrl(String url)
Set the item
link url. |
DisplayData.Item<T> |
withNamespace(Class<?> namespace)
|
DisplayData.Item<T> |
withNamespace(String namespace) |
@Nullable public abstract String getNamespace()
public abstract String getKey()
public abstract DisplayData.Type getType()
DisplayData.Type of display data. All metadata conforms to a
predefined set of allowed types.@Nullable public abstract Object getValue()
DisplayData.item(java.lang.String, java.lang.String) into a format suitable for display. Translation is based on the
item's type.
The value will only be null if the input value during creation was null.
@Nullable public abstract Object getShortValue()
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.
@Nullable public abstract String getLabel()
If no label was specified, this will return null.
@Nullable public abstract String getLinkUrl()
If no URL was specified, this will return null.
public DisplayData.Item<T> withNamespace(Class<?> namespace)
namespace from the given Class.
This method does not alter the current instance, but instead returns a new DisplayData.Item
with the namespace set.
public DisplayData.Item<T> withNamespace(String namespace)
withNamespace(Class)public DisplayData.Item<T> withLabel(String label)
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.Item
with the label set.
public DisplayData.Item<T> withLinkUrl(String url)
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.Item
with the link url set.