org.apache.tapestry5.annotations

Annotation Type Cached

@Target(value=METHOD)
@Retention(value=RUNTIME)
@Documented
@UseWith(value={COMPONENT,MIXIN,PAGE})
public @interface Cached

Indicates that a method should only be evaluated once per request and the result cached. Further calls to the method during the same request will return the cached result. However, if the method's component occurs more than once within an enclosing component, the cached results will be distinct for each occurrence. This annotation is commonly used on getters for component properties:

 @Cached
 Date getNow() {
     new Date();
 }
 

You may not apply @Cached to void methods or methods with parameters. Note that this annotation is inheritance-safe; if a subclass calls a superclass method that has @Cached then the value the subclass method gets is the cached value. The watch parameter can be passed a binding expression which will be evaluated each time the method is called. The method will then only be executed the first time it is called and after that only when the value of the binding changes. This can be used, for instance, to have the method only evaluated once per iteration of a loop by setting watch to the value or index of the loop.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	watch The optional binding to watch (default binding prefix is "prop").

Element Detail

watch

public abstract String watch

The optional binding to watch (default binding prefix is "prop").

Default:

""