Re: [wsrp-coord] supporting properties

[Michael Freedman <Michael.Freedman@oracle.com>]

Close.  The state is neither common nor [necessarily] persistent. 
 Though logically the problem trying to be solved is one of sharing a 
common state in practice because of the isolation of portlets it becomes 
a practice of each island/portlet maintaining its own version of the 
state and defining a mechanism that moves the state between the various 
players when necessary.  Whether any given portlet maintains this 
information persistently or transiently is of no concern [though we 
likely want to know scoping for optimization reasons].  To accomplish 
this "special calls" do need to exist.  First, we need a way for a 
portlet to declare its "public" data [model].  This is the portion of 
data it maintains that it is willing to expose to the consumer/and or 
willing to be set by the consumer.  Then we need a way for this data to 
be sent/received.  For performance reasons one prefers to only send data 
to the consumer when the data changes -- hence you likely return new 
values in your action response.  For times when the consumer  needs 
these values though the portlet isn't the target of an action, a form of 
GetProperty can be used.  This is useful for example when the page is 
first loaded and data needs to flow between the portlets to properly 
 initialize their state. For pushing values to a portlet, a form of 
SetProperty is used.  

The transfer of state logically occurs during the action phase.  An 
action returns changed state values that are then pushed through the 
system.  Once the chain of changes completes the consumer can safely 
render portlets on the page.  The initial state transfer occurs outside 
an action.  For example when a user accesses a page for the first time 
where there is dependencies between two portlets state, the consumer 
bootstraps the state/values by calling getProperty/setProperty directly.

To make this clearer and to show it side by side with a pure event 
system I am hoping to write up a short description of how our Use Case 
works in the "supporting properties" case and the "event" case.  If 
lucky I may have this done for next Wednesday but unfortunaetly doubt it.
     -Mike-

Alejandro Abdelnur wrote:

>
> Finally I got some time to go over the email discussions. Thanks very 
> much for the detailed explanations you've all provided upon my request 
> for clarification.
>
> My understanding is that 'supporting properties' is a mechanism to 
> allow different portlets to share a common persistent state. Portlets 
> could modify this common persistent state. Other portlets will get the 
> updated common persistent state on the next WSRP (action/markup) 
> operation. There are no special calls triggered to the portlet because 
> the common persistent state has changed.
>
> Are my assumptions correct?
>
> Alejandro
>
>
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