On 8/17/10 4:32 PM, Blake Sullivan wrote:

The actual performance of the implementation. We've measured the performance of the current implementation and the overhead is non-negligible. I agree that if the proposal is to reread the context-parameter on each call, that would be far too expensive. Faster, if grosser implementations could involve storing a final boolean on the UIComponent.

How about we combine Ed and Kito's proposals?

Ed:

Due to our iron-clad commitment to backwards compatibility, we keep the
public static final String constants, but alter the behavior, providing
a context-param to restore the old behavior.

The constants will only be honored if the context param is set.

Kito:

Couldn't you modify the map to return the constant values for the proper keys? That way, they would be read-only values that don't need to be stored, the Map just needs to know the keys.

So, the combined solution would be:

By default these keys are not honored. Applications that want to call:

FacesContext.getAttributes().get(UIComponent.CURRENT_COMPONENT)

Instead of:

UIComponent.getCurrentComponent()

(Why?)

Can set a context parameter that forces the the FacesContext implementation to use a Map that specially handles get() calls for the old keys.

For fun, in development project stage we can detect/warn about attempts to reference these attributes by key and recommend the type-safe alternatives.

Andy