Gil,
1) As I replied to Yossi, copy/clone is relevant to WSRP/portlets if
the portlet maintains its personalization data.
2) I agree that the "arbitrary levels" function complicates the portlets
life in managing the personalization data and it will be a challenge to
define this in an abstract way via WSRP so portals can define their own
hierarchies. But I don't think we can avoid doing so. I believe
(and we have found in practice), that there are some portlet providers
that find it unacceptable for the portal to know/maintain anything about
its user preferences. Also some portlets have personalization data
that defines customizations of "push" operations. These are very
difficult to model in a store and pass on request model. A final
note, we have found in practice that having a portlet maintain personalization
data across portal instances does not add complexity (over a single instance).
I am pretty confident we could articulate a model in WSRP that works well.
Good point identifying that it all boils down to who manages the personalization
data -- it has been added to the questions list.
-Mike-
Gil Tayar wrote:
1>How
does your two terms "Serialized/Stored Instance" and "Active Instance"
differ from the one's in my document; "Personalization Data" and "Portlet
Instance"? They seem very similar to me.
"Portlet
Instance" in your document means - "a portlet on a page; or more generically
a portlet in the portal layout structure". If this means a portlet instance
is created only when viewed by the end user (i.e. runtime and not
design time), then my apologies for failing to understand.I
believe my failure to understand came from the list of operations you designated
on portlet instances. For example "You can copy a portlet instance.
By copy it is meant that a second portlet instance comes into being with
its personalization data being a duplicate of the instance it was copied
from". Why does WSRP need such an operation? Instead (In your terminology),
the portal can just create a new instance with the personalization data
used to create the old instance. Now,
I understand why a portal would need to expose such functionality
to the end user (copy/paste of a portal on the page), but why would WSRP?2>Also,
why do you think its important/required that portal store/manage the portlets
(producers) settings and personalization data? Isn't there value
in allowing these portlets to store/maintain this data themselves?
Good
question (and very much related to the first!). This may be true, but remember
that a remote portlet may work with multiple portals (each with
a different user base) at the same time. If we require the portlet to store
customization preferences, then this puts too much burden on portlet. In
the "local" portlet world, the portlet had access to infrastructural code
(of the portal) that can store the preferences for the portlet. This structural
code was usually code supplied by the portal. In the remote portlet world,
the portlet is "alone", and must supply "preference" storage themselves,
i.e. a database. Moreover,
this information must be synchronized with the data stored in the
portal itself about the portal instance (for example, the location of the
portal instance on the page). So the two must be synchronized. But this
is difficult - what happens when the user deletes the portal instance from
the page - should the portal send a "deleteData" message to the portlet?
What if the portlet is "down" at that time? Now the portal needs to queue
the request.Another
(more conceptual/logical) problem is that (and I quote from your document)
"There are an arbitrary set of personalization levels defined by the particular
portal. The levels are hierarchical. The deepest personalization
level that has any overriding values controls the user's view" - do we
expect the portlet to understand this hierarchy and the rules governing
the overriding and inheritance? If portlet's store the personalization
data, then they must. And if they must, then WSRP must define the hierarchy
and the rules. Do we expect WSRP to standardize these? Seems to me that
this is the domain of the portals, and not of the interface.I
think these two questions all boil down to the second one: who manages
the personalization/customization data - the portal or the portlet?Gil
-----Original
Message-----
From: Michael Freedman [mailto:]
Sent: Tuesday, April 09, 2002
00:23
To: Gil Tayar
Cc: ''
Subject: Re: [wsrp][interfaces
and protocols]: Portal using WSRP Service
Gil,
How does your two terms "Serialized/Stored Instance" and
"Active Instance" differ from the one's in my document; "Personalization
Data" and "Portlet Instance"? They seem very similar to me.
Also, why do you think its important/required that
portal store/manage the portlets (producers) settings and personalization
data? Isn't there value in allowing these portlets to store/maintain
this data themselves?
-Mike-
Gil Tayar wrote:
Hi Thomas,
<note>
As I
was not in the F2F, and have not yet posted to this mailing list, I would
like to introduce myself. My name is Gil Tayar, I am the Chief Architect
of WebCollage, and a colleague of Eilon Reshef.
</note>
I very
much liked your life-cycle description, and I think it can provide a descent
framework on which to base WSRP's life-cycle and interface/protocol discussions.
It also complements Mike's more detailed document very well.
To summarize
the states of a portlet, you have the following:
1. Unbound:
The portlet exists, but there is _no_ connection to the portal.
2. Bound:
the portlet is bound, and registered in the portal.
3. Template:
a portlet template is created by the portal, with a given set of parameters.
4. Instance:
A template inside a given user page.
As a member
of WSIA, where states #1-#3 do not "exist" (yet!), I would like to dig
deeper into the "Instance state". It seems to me that this state should
be subdivided into two:
4a. Serialized/Stored
Instance: the template and the customizations the user selected and
put in the page, as it exists in the "persistence store/database" of the
portal.
4b. Active
Instance: the entity used to render the portlet and "do the actions".
I believe
the distinction between the two is an important one, as important as the
distinction between a java object serialized to a stream, and the java
object itself. One (the serialized object or portlet) is "just" data used
to create the other.
To make
another point, the state names I gave are a bit confused. Some are "states"
and some are "entity types". We can deconstruct this further:
Entity
Types -
1. Portlet.
The remote service that responds to WSRP messages.
2. Bound
Portlet. The location and registration information for the Portlet,
as stored by the portal.
3. Portlet
Template. The set of parameters to be used when creating a Stored Instance,
as stored by the portal.
4. Stored
Portlet Instance. The set of customization options to be used for a
certain user page, as stored by the portal.
5. Active
Instance. The viewed portlet, when viewed inside the portal.
The above
lists turns the "states" into more of a list of "operations" which create
entities from other entities -
Operations
-
1. Binding:
a request of the administrator(?) to the portal to register the portlet
and store location and registration information, to be used when creating
a portlet template.
2. Creating
a Template: Using the location and registration information, get the
meta-data, query the administrator(?) for the parameters, and store them.
3. Inserting
Template into Page: User selects a template, customizes it, and creates
a Stored Portlet Instance from it.
4. Viewing
the Portlet: User opens portal, and the portal creates an Active Instance
from the Stored Instance.Hope it makes sense,Gil-----Original
Message-----
From: Thomas Schaeck [mailto:]
Sent: Sunday, April 07, 2002 18:19
To: Michael Freedman;
Subject: Re: [wsrp][interfaces and protocols]: Portal
using WSRP Service
Hi Mike,
here's the life-cycle writeup I promised:
Binding to a WSRP Service
-------------------------
Pre: - The Portal and the WSRP Portlet Service are not
bound -
1. The administrator browses the directory for WSRP services
using the
portal admin UI -->
- The Portal finds the WSRP Portlet Service in the directory
2. The administrator selects a WSRP service -->
- The Portal makes a call or series of calls to the WSRP
Portlet Service to
establish a relation (bind) (may include establishing
a trust relation, see
my security note)
- The Portal creates a portlet template referencing the
WSRP portlet
service. (Potentially, the template may need to be parameterized
with
template settings to become usable.)
Post: - The portal is bound to the WSRP service through
the portlet
template, users may now see the template beeing offered
in the portal's
customizer -
Creation of Instances
---------------------
Pre: - The portal is bound to the WSRP service through
the portlet
template, users may now see the template beeing offered
in the portal's
customizer/toolbox -
3. A portal user selects the portlet template to be put
on a page -->
- The portal server creates a portlet instance from the
portlet template
- The portal server links the instance to the user's
page
Post: - The portal is bound to the WSRP service through
the portlet
template, users may now see the template beeing offered
in the portal's
customizer/toolbox and a unique instance which may have
persistent data now
exists for the user
Destruction of Instances
------------------------
Pre: - The portal is bound to the WSRP service through
the portlet
template, users may now see the template beeing offered
in the portal's
customizer/toolbox and a unique instance which may have
persistent data now
exists for the user
4. A portal user discards a portlet instance from a page
-->
- The portal discards the link from the page to the instance
- The portal discards the instance
Pre: - The portal is bound to the WSRP service through
the portlet
template, users may now see the template beeing offered
in the portal's
customizer/toolbox, the unique instance does no longer
exist
Unbinding a WSRP service
------------------------
Pre: - The portal is bound to a WSRP service through a
portlet template,
users may now see the template beeing offered in the
portal's customizer -
5. The adminstrator browses the list of portlet tempplates
and discards the
portlet template -->
- The portal makes a call to the WSRP Portlet Service
referenced in the
portlet template to undo the binding
- The portal discards the portlet template
Post: - The Portal and the WSRP Portlet Service are not
bound -
Best regards,
Thomas
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