To say this another way, PPs enable
user/Consumer driven coordination. The current question is whether to allow
Portlets to generate URLs that enable the user driven portion of this rather
than requiring such URLs be generated by the Consumer. I think the use
cases Stefan posted say there is value to allowing Portlets to generate
such URLs.
Rich
Michael Freedman <>
07/27/05 10:13 AM
To
cc
Subject
Re: [wsrp-interfaces] Fw:
[wsrp] Additional use cases for issue #44 (set new public params)
Yes, and the beauty of this is it is exactly what we had
defined until we started down this road of shared PP names. I.e.
its already defined and done -- and we can roll onto other issues.
-Mike-
Andre Kramer wrote:
I do see the usefulness of
a limited consumer to portlet value sharing, with the consumer supplying
values for “slots” requested by a portlet with no push back by the portlet.
Anything that updates values to be held by the consumer (e.g. the shared
timezone) to me implied that the changes be propogated to the consumer’s
store and to other portlets to be useful. Maybe that is all we can support
in 2.0 (with some error feedback channel as I previously suggested).
Regards,
Andre
From: Michael Freedman [mailto:]
Sent: 27 July 2005 13:13
To:
Cc: Michael Freedman
Subject: Re: [wsrp-interfaces] Fw: [wsrp] Additional use cases for
issue #44 (set new public params)
Yes, I am in the U.K. this week
enjoying the sunny weather :-)
The base PP use case is one where the consumer wants to [in part] drive
the content the portlet produces. The simple example I used way back
when was a portlet that was locale [zip code] specific such as the weather
portlet. By publishing the PP for zip code the consumer could drive
the content of this portlet -- for example by using information from the
current user's user profile, or using a predefined [page] value, or even
a value it publishes/recognizes from URLs submitted by its clients. In
each of these cases the value is commonly request dependnent. In
this base scenario the PPs are local to a portlet [each portlet's are independent].
Coordination is established/managed by the consumer when it decides
to use the same values for PPs in differing portlets. I.e. this mechanism
allows a Consumer to coordinate with a producer. What it doesn't
do is allow one producer/portlet to coordinate with another. We have
events for this. Currently, we are discussing expanding PPs so they
can also be used as an optimization mechanism for portlet to portlet coordination.
I am okay with us doing that if we don't expand/change the base semantics
of PP [i.e. its public navigational state] and we prefer this mechanism
over a type of transient property mechanism we might add in the future.
Personally, I currently think transient properties will be the better/best
solution, once we define them and that we should wait vs. using PPs so
as not to confuse folks later by giving them too many options for doing
roughly the same thing. I don't see that our lack of support for
this optimization in 2.0 would be bad -- the function is doable via events
just a little less efficiently.
My comments on PerformInteraction were not really in relation to PPs. I
am trying to separate these some. My PerformInteraction comment suggests
rather then overload getMarkup and misshandling the definition we already
seem to have defined a mechanism that fits the purpose proposed. If
so then we should use it. When the follow-on question arises of how
do I encode/do cross portlet coordination with a performInteraction URL
-- my answer looks back to the independent decision we made above. If
we decide that transient properties is the right way to do this, then in
WSRP 2.0 the answer is you can't -- you either wait for us to add transient
properties or you use a BlockingInteraction/event. If our answer
to the above is we are willing to live with the limited set of semantics
you get when you define Public Navigational state where consumers are required
to coordinate providing a consistent value when like names are used --
then you have the support we will add for setting/encoding PPs.
-Mike-
Andre Kramer wrote:
Hi Mike (you must be on UK
time),
Could you describe a use case
were the PP is just shared between the consumer and one portlet? The only
ones I can think of are really scenarios for a complex consumer (also know
as rich or smart client) that should be doing Web Services calls that are
application specific rather than piggy backing on a generic protocol like
WSRP.
My confusions about the separate
issues may be caused by not seeing uses that are not communicated between
portlets (what I would call shared but non-public) or not maintained between
requests (what I would call transient). PPs promised to make coordinated
values (such as current time zone communicated to multiple portlets) easier
for portlet programmers than full blown event handling but seem to require
that they be public and non-transient.
Thinking ahead, relaxing the
blocking semantics of actions would help but would this not take the event
handling communication round out of such interactions hence forcing (or
encouraging depending on viewpoint) use of PPs? I think I would rather
encourage use of events and discourage PPs.
Regards,
Andre
From: Michael Freedman [mailto:]
Sent: 27 July 2005 09:42
To:
Cc: Michael Freedman
Subject: Re: [wsrp-interfaces] Fw: [wsrp] Additional use cases for
issue #44 (set new public params)
How did we take two separate discussions/issues,
fuse them into one and make the resulting discussion even more cloudy?
Anyway, on PP let's get back to basics.
Didn't we decide a few weeks back that we were not going to design/describe
transient properties in this realease?
Didn't we decide that PP were a separate concept from transient properties?
And that the distinction between the two is that PP is public navigational
state with no defined consumer scope while transient properties are consumer
managed state with defined scope?
And don't we define public navigational state semantics as equivalent to
regular navigational state semantics except that the value is not opaque
to the consumer?
So isn't the only issue here whether the use cases Stephan and Richard
have given us are reasonable/preferrable to solve via PP [as compared to
using either events or the to be designed transient properties]?
If so, here are my comments...I think we need to compare constrast supporting
these use cases with PP vs transient properties. PP doesn't introduce
any notion of shared state -- each portlets navigational state is its own.
Transient properties will likely support a notion of shared state.
Yes, we can add some conventions to PP to require the consumer to
associate PPs with the same name meaning they should receive the same values
-- and this is what we have suggested we use to support the use cases.
If we want this semantics then, yes we need to offer equivalent mechanisms
to the portlet to set public navigational state as we do regular navigational
state. I think Rich's proposal does this. If we end up thinking
that once we have transient properties it will make more sense to support
these use case with them [since the scope of sharing will likely be defined/influenced
by the portlets] then I would suggest it might be better if we didn't
add this behavior to PPs and merely leave them restricted to the defining
portlet. If we choose this later approach then we don't need any
way for the portlet to set PPs as setting regular navigational state should
suffice. [And remember, the use cases are supportable in 2.0 via
events while we wait for a more efficient mechanism in 3.0].
As for supporting method GET for render URLs, as I said last week, it seems
what is being proposed here is exactly what performInteraction was all
about. Why isn't this merely a proposal that we add performInteraction
back into the specification? Rich, can you dust off the old performInteraction
description and send it out to folks so we can see if we already have a
completely designed and if I recall agreed upon set of semantics?
-Mike-
Rich Thompson wrote:
I'm sorry, but I find the whole SOAP vs REST debate irrelevant to this
discussion.
There are some key questions though:
1. Does the semantics of getMarkup match that of HTTP GET so that Consumers
can use GET for render links?
If the answer to #1 is yes (I think it is), then:
2. If PPs are added to URLs, can the Consumer support them for the scope
of the user interaction across all portlets on the page without violating
HTTP GET semantics?
3. If PPs are added to URLs, can the Consumer support them for a scope
encompassing multiple user interactions across all portlets interacted
with and not violate HTTP GET semantics?
I think the answer to all three questions is yes, though #3 requires the
Consumer to support PPs as part of its own navigation state. Common web
usage would also allow storing the PPs in a user session, though technically
this would violate GET semantics as it is an update of server-side state.
Rich
"Andre Kramer" <>
07/26/05 10:05 AM
To
Rich Thompson/Watson/IBM@IBMUS,
<>
cc
Subject
RE: [wsrp-interfaces] Fw: [wsrp]
Additional use cases for issue #44 (set new public params)
But surely the (if any) desire is to enable GET semantics between the browser
and the consumer Portal for optimized “render” interactions? All WSRP
operations today use SOAP (and therefore POSTs) and are explicitly not
REST. In any case, I would argue for a simple developer model that supports
the use cases. These, for me, naturally require a statefull consumer to
serialize updating changes to shared public parameters or could possibly
be poorly supported by a set-for-one-interaction /one-shot imposed limitation.
I don’t particularly wish to go down the “Web GET/POST semantics” rat
hole for WSRP just for such a limitation.
Regards,
Andre
From: Rich Thompson [mailto:]
Sent: 26 July 2005 14:15
To:
Subject: RE: [wsrp-interfaces] Fw: [wsrp] Additional use cases for
issue #44 (set new public params)
I can definitely see useful coordination happening without the reversion
you describe if the Consumer chooses to treat PPs as part of the Consumer's
navigational state. This keeps it from impacting state managed server-side
(i.e. is compatible with GET semantics) while enabling ongoing, state-oriented
coordination of the portlets being rendered for the user (i.e. once the
zipcode PP is set, it stays at that value until it is reset by some other
user/Consumer/portlet action).
Rich
"Andre Kramer" <>
07/25/05 10:43 AM
To
Rich Thompson/Watson/IBM@IBMUS,
<>
cc
Subject
RE: [wsrp-interfaces] Fw: [wsrp]
Additional use cases for issue #44 (set new public params)
Could Stefan & Richard please remind us as to when it is useful to
have a render URL affect other portlets on a page (just) for the duration
of one page fetch, when a subsequent refresh (browser button) is likely
to revert to the previous consumer state (as nothing permanent is being
implied spanning consumer/portlets)?
I suspect any useful coordination state change seems more related to a
consumer effectively tracking and forwarding shared values and so the Web
request to the consumer should itself be a POST to the consumer/Portal?
Given PPs on render URLs that don’t last v.s. PPs in action replies that
do (SHOULD/MUST) aren’t developers going to choose actions anyway, e.g.
updating a charting page’s units from imperial to metric?
Regards,
Andre
From: Rich Thompson [mailto:]
Sent: 25 July 2005 15:02
To:
Subject: Re: [wsrp-interfaces] Fw: [wsrp] Additional use cases for
issue #44 (set new public params)
I think it might be time to pull this discussion back out of the abstract
space and relook at the use cases we have accepted as compelling.
Stefan & Richard have posted some use cases that clearly would benefit
from PPs being settable on URLs and need a PP scope of at least the user
interaction ... including all portlets accessed during the processing of
the user interaction. Could you post use cases requiring broader scopes?
I presume that if we find them compelling, my answer to Mike's previous
inquiry about requiring Consumers to support PPs may need to change.
Rich
Subbu Allamaraju <>
07/25/05 09:06 AM
To
cc
Subject
Re: [wsrp-interfaces] Fw: [wsrp]
Additional use cases for issue #44 (set new public params)
Stefan,
This is question of scoping.
As we have been debating, there are two options to let portlets update
some shared state (public params). The first option is to let portlets
encode such change in URLs, and the second is to let producers return
new public params within SOAP.
Apart from the encoding rules, these options influence scoping of this
shared state that consumers can implement. If you go with the first
option, consumers will have to limit this shared state to a user's
session or just a few portlets on a given page. IMO, this is restrictive.
However, if you go with the second option, consumer has more choice.
Consumers can implement wider scoping of this shared state.
Subbu
Stefan Hepper wrote:
> I think this is mixing sematics. Anything that requires a pbia is
ment
> to be a resource state change. For resource changes you need a blocking
> semantic. Navigational state and public params in my mind define the
> view state of the portlet and changing this state does not require
a
> pbia nor a non-blocking action. The new parameters or state can just
be
> provided to the portlet.
>
> This also relates to the W3C standard about GET and POST:
>
> " * Use GET if:
> o The interaction is more
like a question (i.e., it is a safe
> operation such as a query, read operation, or lookup).
> * Use POST if:
> o The interaction is more
like an order, or
> o The interaction changes
the state of the resource in a way
> that the user would perceive (e.g., a subscription to a service),
or
> o The user be held accountable
for the results of the
> interaction."
>
> I don't see why it is necessary to pay the penalty of an action for
> changing PPs.
>
> Stefan
>
>
>
> Subbu Allamaraju wrote:
> > Rich Thompson wrote:
> >
> >>
> >> My comment was that requiring action processing is
always possible,
> >> but why would we require it in this case and not for
> >> mode/windowState/navState changes?
> >
> >
> > I agree, but the difference is the encoding rules.
> >
> > Subbu
> >
> >>
> >> Rich
> >>
> >>
> >> *Subbu Allamaraju <>*
> >>
> >> 07/22/05 09:48 AM
> >>
> >>
> >> To
> >>
> >> cc
> >>
> >> Subject
> >> Re: [wsrp-interfaces] Fw: [wsrp] Additional
use cases for issue
> >> #44 (set new public params)
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> Thinking aloud, can't we map render URL use cases to
use pbia? The
> >> reason for changing the value of a paramter could be
the result of a
> >> user interaction, which can then compute new values
and return with
> pbia
> >> response.
> >>
> >> Subbu
> >>
> >>
> >> Rich Thompson wrote:
> >> >
> >> > It is possible to drive every style of update
through action
> >> processing,
> >> > but I think that short changes the advantages
of using render URLs
> >> where
> >> > they are appropriate.
> >> >
> >> > New navState can be specified on each URL
(including render
> URLs), why
> >> > should not the Portlet be able to specify
the shared version (PPs)?
> >> >
> >> > Rich
> >> >
> >> >
> >> > *"Andre Kramer" <>*
> >> >
> >> > 07/22/05 08:02 AM
> >> >
> >> >
> To
> >> >
Rich Thompson/Watson/IBM@IBMUS,
> >> <>
> >> > cc
> >> >
> Subject
> >> >
RE: [wsrp-interfaces] Fw: [wsrp] Additional use
> >> cases for issue #44
> >> > (set new public params)
> >> >
> >> >
> >> >
>
> >> >
> >> >
> >> >
> >> >
> >> > After reading your previous email, I was
driving towards a similar
> >> > recommendation for Portlets to “re-fresh”
public parameters by
> >> return on
> >> > each WSRP interaction so that a consumer
is more likely to forward
> >> > values that have been recently actively
returned and I agree this
> >> means
> >> > Portlets have to maintain/store public param
values e.g. in
> >> navigational
> >> > state. But, with such advice, I see no reason
to have public
> >> parameters
> >> > to visibly appear on URLs (rewrite expressions
or templates) at
> >> all. Why
> >> > introduce a new encoding and (in markup)
transport mechanism when it
> >> > seems a preferable Web Service (in SOAP
response) encoding and
> >> transport
> >> > is already available and recommended?
> >> > > Regards,
> >> > Andre
> >> > >
> >> >
> >>
> ------------------------------------------------------------------------
> >> >
> >> > *From:* Rich Thompson [mailto:]
*
> >> > Sent:* 22 July 2005 12:24*
> >> > To:* *
> >> > Subject:* Re: [wsrp-interfaces] Fw: [wsrp]
Additional use cases for
> >> > issue #44 (set new public params)
> >> > >
> >> > The Interfaces SC discussion raised the
question about the scope of
> >> PPs
> >> > set in this manner. Namely; does the Portlet
need to keep
> >> specifying the
> >> > PPs on all subsequent requests or can it
depend on the Consumer to
> >> > resupply those values in the future (i.e.
some scope, like
> >> user-session,
> >> > becomes mandated).
> >> >
> >> > I think we should be careful to leave scoping
questions up to the
> >> > Consumer, but if PPs are to function as
a coordination model,
> then we
> >> > also have to discourage Portlets from setting
all PPs on every
> URL. A
> >> > model where Portlets are encouraged to store
current PP values
> >> > (preferably in navState) for use as default
values should the
> Consumer
> >> > not supply a value on a subsequent invocation
and only do PP setting
> >> > when a value needs to change accomplishes
this. It removes
> setting the
> >> > value each time such that coordination happens
in a more reasonable
> >> > manner while also providing for reasonable
user experience, even
> when
> >> > the Consumer does not support and PP scope
beyond the user
> >> interaction.
> >> >
> >> > Note: We could consider a model where Portlets
MUST encode all
> PPs on
> >> > all URLs such that this supplies the scope,
rather than the Consumer
> >> > determining the scope, but that this fails
as the Portlet might not
> >> have
> >> > access to all PPs (security and privacy
reasons).
> >> >
> >> > Rich
> >> >
> >> > *Rich Thompson/Watson/IBM@IBMUS*
> >> >
> >> > 07/07/05 11:54 AM
> >> >
> >> >
> To
> >> >
> >> > cc
> >> >
> Subject
> >> >
[wsrp-interfaces] Fw: [wsrp] Additional use cases
> >> for issue #44 (set
> >> > new public params)
> >> >
> >> >
> >> > >
> >> >
> >> >
>
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > Reposting, as requested ...
> >> > ----- Forwarded by Rich Thompson/Watson/IBM
on 07/07/05 11:52 AM
> -----
> >> >
> >> >
*Rich Thompson/Watson/IBM@IBMUS*
> >> >
> >> > 06/15/05 09:24 AM
> >> >
> >> >
> To:
WSRP TC
> >> <>
> >> > cc:
> Subject: Re:
[wsrp] Additional use
> >> cases for issue #44 (set
> >> > new public params)
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > I had taken a to-do from the Interfaces
SC to develop (in
> conjunction
> >> > with Stefan, Richard and Mike) a proposal
for this portion of Issue
> >> #44.
> >> > Here is that proposal: *_
> >> >
> >> > Philosophy:_* Since Public Parameters (PP)
are another aspect of
> >> > Consumer managed state that is exposed to
Portlets (the other two
> are
> >> > modes and windowState), Portlets should
be able to request
> changes to
> >> > PPs in much the same way as they do modes
and windowStates (on URLs
> >> and
> >> > in responses from pbia and handleEvents).
*_
> >> >
> >> > On URLs: (2 issues)_*
> >> > 1. Need to encode 3 pieces of information
(request to set a PP, the
> >> > PPname and the PPvalue) into 2 places (name=value)
when using a
> >> > querystring and deal with the reduced set
of characters allowed
> in the
> >> > path portion ('=' is not allowed). Templates
also introduce an issue
> >> > with how to encode multiple PPs ... preferably
with the Template
> only
> >> > having a single placeholder.
> >> > -Proposal:
> >> > 1. All public parameters specified on a
URL are concatenated in the
> >> form
> >> > of "PPname1=PPvalue1&PPname2=PPvalue2".
> >> > 2. The resulting string is URL encoded (changes
'=' into %3D and '&'
> >> > into %26) to make it valid in both the querystring
and path
> >> portions of
> >> > a URL.
> >> > 3. This URL encoded string becomes the value
for the
> >> > wsrp-publicParameter URL parameter, regardless
of whether template
> >> > processing or Consumer URL rewriting is
in use.
> >> >
> >> > 2. How to encode complex PPvalues? I suggest
serializing the
> >> PPvalue to
> >> > XML and URL encoding this XML. The Consumer
would then receive
> the PP,
> >> > recognize it is of a complex type (based
on PPname) and decode the
> >> > PPvalue to get the XML. *_
> >> >
> >> > On Operation responses:_*
> >> > 1. Return PP requests via a field much as
newMode and newWindowState
> >> > request updates to those aspects of Consumer
managed state. Suggest
> >> this
> >> > field be of type QNamedStringArray, though
it could be an array of
> >> > NamedString if we do not want to introduce
a usage of a type from
> the
> >> > 'extra' namespace.
> >> >
> >> > Rich
> >> >
> >> > *Michael Freedman <>*
> >> >
> >> > 05/24/05 07:55 PM
> >> >
> >> >
>
> >> >
> >> > To
> >> >
WSRP TC <>
> >> > cc
> >> >
> Subject
> >> >
Re: [wsrp] Additional use cases for issue #44 (set
> >> new public params)
> >> >
> >> >
> >> >
> >> >
> >> >
>
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > I too am interested in hearing people's
current opinions. Our early
> >> > coordination discussions considered this
carefully. It was
> decided at
> >> > that time to not support two coordination
models that delivered
> >> > equivalent function. Though I pushed
strongly for such a parameter
> >> > style mechanism, the subcomittee preferred
Events because it not
> only
> >> > allowed state to be transferred but also
actions. The current
> public
> >> > parameter model was introduced by me later
and was crafted
> >> specifically
> >> > to not step on the the toes of Events.
>
> >> > To extend this conversation I would like
to pose:
> >> > 1. We consider
whether publicParameters should be QNames so
> >> they
> >> > can be shared/reused across producers. Note:
this is likely needed
> >> > whether we stick with events or add the
ability to encode a public
> >> > parameter directly in the URL.
> >> > 2. We consider
adding a new "defined event" called
> >> > publicParameterValueChanged. The payload
of this event would be the
> >> > QName of the parameter and an Object any
holding the parmeter value
> >> > [though it might be nice to support our
Any/String optional pair
> style
> >> > here].
> >> > 3. We consider
defining the meaning of publicParameter whose
> >> > capability contains the value "required"
as meaning that normal
> >> usage of
> >> > this portlet requires the consumer to provide
this value. The
> portlet
> >> > would still have to deal with situations
in which this wasn't
> provided
> >> > but likely an end-user would consider this
usage
> crufty/abnormal. For
> >> > example if a portlet required a CustID parameter
and didn't receive
> >> one
> >> > it could display a view that asks for a
custID. The key here by
> >> saying
> >> > "required" [we can choose a different
capability name] the consumer
> >> can
> >> > distinguish between those public parameters
that have a secondary
> >> impact
> >> > on the portlet [optional] and those that
have a primary or important
> >> > impact [required].
> >> > -Mike-
> >> >
> >> > Stefan Hepper wrote:
> >> > Hi,
> >> > I've some use cases that may be a good match
for the ability to set
> >> new
> >> > public parameters by the producer and to
encode public parameters in
> >> > URls by the producer.
> >> >
> >> > 1. displaying content based on a specific
product id:
> >> > - Portlet A allows to select a product from
a list
> >> > - User clicks on a specific product
> >> > - Portlet B renders details of this product
> >> > - Portlet C renders currently available
number of items on stock for
> >> > this product
> >> > - user wants to bookmark this result in
order to come back to
> product
> >> > tomorrow
> >> >
> >> > implementation with events:
> >> > Portlet A encodes the customer selection
URLs as POST action links
> >> > Portlet A receives a performBlockingInteraction
call
> >> > Portlet A returns event productID=10
> >> > Portlet B receive a blocking handleEvents
call for productID=10 and
> >> > returns new navigational state
> >> > Portlet C receive a blocking handleEvents
call for productID=10 and
> >> > returns new navigational state
> >> >
> >> > implementation with public params:
> >> > Portlet A encodes the product selection
URLs as GET render links
> with
> >> > the productID as public param
> >> > Portlet A receives a render call with the
public param productID=10
> >> > Portlet B receives a render call with the
public param productID=10
> >> > Portlet C receives a render call with the
public param productID=10
> >> >
> >> > which would be much more efficient and also
consistent with the W3C
> >> > architecture as links that do only change
view state should be
> encoded
> >> > as GET links.
> >> >
> >> >
> >> > 2. display content based on a specific customer
id
> >> >
> >> > 3. display content based on the selected
state of a map
> >> > portlet A displays a map of USA
> >> > portlet B displays information on the selected
state (# people
> >> > registered, capital, ...)
> >> > portlet C displays all IBM labs in that
state
> >> >
> >> > and many more.
> >> >
> >> >
> >> > This would allow to have some gobal navigational
state that can
> be set
> >> > via URLs by portlets. Also portlets may
want to set new public
> >> params as
> >> > a result of an blocking interaction or a
handle event call.
> >> >
> >> >
> >> > What do you think?
> >> >
> >> >
> >> > Stefan
> >> >
> >> >
> >> >
> ---------------------------------------------------------------------
> >> > To unsubscribe from this mail list, you
must leave the OASIS TC that
> >> > generates this mail. You may a link
to this group and all your
> TCs in
> >> > OASIS
> >> > at: _
> >> >
> >>
> __https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php_
> >> >
> >> >
> >>
> ---------------------------------------------------------------------
To
> >> > unsubscribe from this mail list, you must
leave the OASIS TC that
> >> > generates this mail. You may a link to this
group and all your
> TCs in
> >> > OASIS at:
> >> >
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
> >> >
> >>
> >>
> >
> >
>
>
