Re: [jsr-314-open-mirror] [jsr-314-open] [2.1 Spec Review] Transient State [Was: Fix UIData state saving model]
Since we can always add the TransientStateHelper later if we need it,
we shouldn't have it in the specification for this release.
-- Blake Sullivan
On 10/22/10 4:25 AM, Andy Schwartz wrote:
Hey Martin -
Here is how I was thinking about this...
With transient properties, we have two types of use cases:
1. Components storing transient attributes on themselves.
2. External classes storing transient attributes on components.
The use case you mention below falls under #1.
In earlier threads there were a references to use cases that fall
under #2 (eg. a renderer setting a transient property on a component).
If we go with the original API proposal of adding public methods to
UIComponent, ie:
- public Object getTransient(Object key)
- public Object putTransient(Object key, Object value)
We have everything we need to address #1 and #2. Your sample below
can be rewritten as:
Double getCalculatedWeight() {
return (Double) getTransient(PropertyKeys.weight, false);
}
void setCalculatedWeight(Double weight) {
putTransient(PropertyKeys.weight, weight);
}
I don't see how adding a new TransientStateHelper contract improves
this situation. That's not to say that we cannot do this. The first
patch that I provided leaves TransientStateHelper in place. Just
seems like added conceptual overhead that might not be necessary.
Andy
On 10/22/10 7:02 AM, Martin Marinschek wrote:
> Hi Andy,
>
> maybe I am missing something here, but isn't the normal use-case for
> this a new component which adds a transient attribute?
>
> something like: calculatedWeight. This should of course be exposed via
> the API of the component - so there should be a:
>
> Double getCalculatedWeight();
> void setCalculatedWeight(Double weight);
>
> And my point was that the implementation of these stateless getters
> and setters should look similar to the stateful version.
>
> What I would do:
>
> Double getCalculatedWeight() {
> return (Double) getTransientStateHelper().get(PropertyKeys.weight,
> false);
> }
> void setCalculatedWeight(Double weight) {
> getTransientStateHelper().put(PropertyKeys.weight, weight);
> }
>
> Could TransientStateHelper not be an alternative implementation of the
> StateHelper interface?
>
> best regards,
>
> Martin
>