TransientProperties

Here is the writeup I volunteered to produce last week which extends
the current notion of PublicParameters to add transient property like
capabilities.   This should get people's juices flowing:

Summary:

Address the various incoming requirements by adding two new concepts:

  
TransientProperties:  properties whose values are managed by the
consumer for a transient length of time [as defined by a consumer
scope].

  
Shared PublicParameters vs. Local PublicParameters:  distinguish
between two types of public parameters.  Shared public parameters are
shared in that they are defined a single consumer managed namespace. 
Local public parameters aren't shared in that they are defined in a per
[wsrp] portlet namespace.  

  

The first concept allows a producer to indicate the lifetime this
property should be maintained.  Request means the property's value is
only maintained for the duration of the client request.  Current or new
values must be established in each subsequent request.  Session means
the property's value is maintained for the duration of the consumer's
client/user session.  While the session remains intact, the property's
value is maintained until explictly set.

The second concept allows a producer to indicate whether the property
it is placed in a global shared consumer space or a local per portlet
space.  The former allows two or more cooperating consumer component's
to share a value while the later ensures the portlet has a discretely
managed value [though this value may be impacted by others via a
consumer supplied wiring mechanism].

Note:  An open, unresolved issue is whether the transient property
scope is considered part of the namespace or not.  I.e. what do we do
if two portlets publish a shared public parameter foo.bar but each
publishes at a different transient scope [request and session]?  Do we
use these scopes as "hints" and defer to the greater scope [session]? 
Do we publish at each scope and view them as separate values?

Setting values:

A shared or local public parameter value can be set in a variety of
ways:

  
By the client -- we would define the URL parameter name mapping
to both shared and local public parameters so clients can express
values for them directly in the request URL. Note: we would have to
define what happens if duplicate parameters appear in the request for a
scalar type.

  

  
In a portlet's Action or Render URL - based on the name mapping
defined above we would allow portlet's to render action and render URLs
which directly express new values for either shared or local public
parameters.

  
As a result of an action or event.

  

Details of each of these to be provided later if the general appraoch
is abgreed upon.

Anyway:  the structural details:

For review: 

PropertyDescription

    [R] QName        name

    [R] QName              type

    [O] LocalizedString    label

    [O] LocalizedString    hint

    [O] string             capabilities[]

    [O] Extension          extensions[]

TransientPropertyDescription extends PropertyDescription

     [R] string      scope [wsrp:request, wsrp:session, .... open ended
list so new scopes can be added]

RuntimeContext

    [R] string        userAuthentication

    [O] Key           portletInstanceKey

    [O] string        namespacePrefix

    [O] Templates     templates

    [O] ID            sessionID

    [O] Property      sharedPublicParameters[]

    [O] Property      localPublicParameters[]

    [O] Extension     extensions[]

     -Mike-