Re: [wsrp-interfaces] Applet resources through WSRP

[Rich Thompson <richt2@us.ibm.com>]

If people don't mind, lets walk into
this carefully (I am certainly not an expert on how portals manage urls).

Consider, for the local portlet case,
how the eventual urls gets constructed:
1.        The
Portlet begins with a local/relative URL; example: relative path to a CSS
file
2.        The
Portal adds to the URL items such as host and context path to form an absolute
url
3.        The
loaded resource contains a local/relative URL; example: a style specifies
a background gif
4.        The
xxx forms the absolute url.
 
If xxx in step #4 is the browser, I
would think it would use the baseURL of the page and therefore construct
an absolute url which failed to point at the gif. If instead it uses the
url of the css file, I would suspect the relative reference to work (including
working with WSRP).

if xxx in step #4 is the Portal, I would
think it already has a facility for preprocessing resources that could
be leveraged to generate WSRP type urls using either Consumer url rewriting
or Producer template processing.

Rich

"Spector, Artem" <artem.spector@sap.com>

03/23/05 11:31 AM

To	<wsrp-interfaces@lists.oasis-open.org>
cc
Subject	RE: [Fwd: Re: [wsrp-interfaces] Applet resources through WSRP]

Yes, the “entire user experience”
was our purpose. From that point of view the URL string of some resource
should be the same whether this URL “originates” from a Portlet code
or from a resource text.
 
Usually building of Portlet-originated
URL takes 3 steps:
1.        The
Portlet begins with a local/relative URL
2.        The
Producer adds to the URL the servlet path (including host and context path)
3.        The
Consumer wraps the producer-side URL with its own servlet path (using templates
or consumer-side rewriting).
 
Now let’s consider a resource
file containing some local URL. If the Producer just indicates wsrp-requiresRewrite,
then the Consumer has to deal with this local URL directly. Returning to
the 3-step example, the step 2 is missing. 
 
Honestly I don’t see how the Consumer-side
parsing/rewriting of resource content can be implemented without any Producer
assistance.
 
Artem

---

From: Rich Thompson [mailto:richt2@us.ibm.com]
Sent: Wednesday, March 23, 2005 5:28 PM
To: Subbu Allamaraju
Subject: Re: [wsrp-interfaces] Applet resources through WSRP
 

I agree with the issues you raise. However, if the Producer is doing the
url production, it must do it in a manner that will work for the entire
user experience ... including resources. The idea would be to point out
these issues to implementers and provide some guidance on how they could
be addressed. One of the options could be to use templates for url production
in the markup and then mark resource as needing Consumer url rewriting,
but Artem points out that other options exist if the Producer is willing
to manage things properly. 

Rich

Subbu Allamaraju <subbu@bea.com>

03/23/05 10:17 AM

To	wsrp-interfaces@lists.oasis-open.org
cc
Subject	Re: [wsrp-interfaces] Applet resources through WSRP

 

I agree with that. I'm referring to your comment "the Producer must also
use the templates on the relevant urls within the resource". Such a
requirement, if placed, would assume that the Producer has control over
resource serving, and that it has the templates handy. Both of these may
not be true in most cases.

Subbu


Rich Thompson wrote:
>
> Section 10.2.1.1.3.2 of WSRP v1 lays the burden on the Consumer to parse
> and rewrite urls for resources that set wsrp-requiresRewrite to true.
> Discussion of this requirement within the TC limited the burden to
> string parsing with a replacement of matching substrings. As such, all
> textual types, including CSS, should be parsed. It is likely best if the
> Consumer is agnostic to the resource's mimetype other than a
> determination of what, if any, of the rewritten url needs to be escaped
> in order for it to be valid within the containing document.
>
> Rich
>
>
> *Subbu Allamaraju <subbu@bea.com>*
>
> 03/23/05 09:58 AM
>
>                  
> To
>                  wsrp-interfaces@lists.oasis-open.org
> cc
>                  
> Subject
>                  Re: [wsrp-interfaces] Applet resources through WSRP
>
>
>                  
>
>
>
>
>
> Rich Thompson wrote:
>  >
>  > It sounds like you are mixing two issues here:
>  >
>  >    1. You have validated that applet use has the same issues as any
>  >       other url, but not a large set of new issues. As a special note;
>  >       resource urls require full name preservation, whether it be a .gif
>  >       or a .jar.
>  >    2. When Producers use templates for url production and referenced
>  >       resources also contain urls, the Producer must also use the
>
> Can you confirm if the spec requires Producers to rewrite resources it
> is serving over HTTP? AFAIR, this is only a requirement on Consumers
> when the MIME type of the resource is text/xml-like. I think the
> requirement on Producers  has implications that we've not discussed in
> detail.
>
>  >       templates on the relevant urls within the resource. This will
>  >       become easier with the new getResource operation (important pieces
>  >       of data are passed on the invocation), but can be also done by
>  >       providing a resolver and passing any required info on the url (or
>  >       in cookies, though I would prefer to not explicitly name that
>  >       option). Note: this includes namespace resolving as well as url
>  >       rewriting.
>  >
>  >
>  > Rereading your post, is there also an issue with not all Consumers
>  > rewriting urls within resources (as per the specs requirements)?
>  >
>  > I think a couple of additions to the FAQ and Primer from this
>  > information might be in order.
>  >
>  > Rich
>  >
>  >
>  > *"Spector, Artem" <artem.spector@sap.com>*
>  >
>  > 03/23/05 05:03 AM
>  >
>  >                  
>  > To
>  >                  <wsrp-interfaces@lists.oasis-open.org>
>  > cc
>  >                  
>  > Subject
>  >                  RE: [wsrp-interfaces] Applet resources through WSRP
>  >
>  >
>  >                  
>  >
>  >
>  >
>  >
>  >
>  > Yes, we’ve found a solution (we work together with Avi) and I’d like to
>  > share it with you.
>  >  
>  > Actually there are two challenges when composing consumer-side URLs for
>  > producer-side resources:
>  > 1.        In some cases the resource name must be preserved in the
>  > consumer-side URL (like .jar for applets)
>  > 2.        Nested resources – if a css contains URLs, they must be
>  > rewritten as well.
>  >  
>  > The solution includes the following aspects:
>  > 1.        The Consumer modifies the URLs so that they will end up with
>  > the resource names.
>  > 2.        The Portlets use a standard API to output resource URLs. In
>  > WSRP scenario these calls are intercepted by the Producer, which does
>  > the necessary conversions (for example, URL writing using templates).
>  > 3.        If the URL references a resource containing other URLs (like
>  > css or js), the producer replaces the resource URL with a URL pointing
>  > to a special producer-side servlet. This servlet acts as a filter when
>  > downloading the resource, and rewrites all the URLs it contains.
>  >  
>  > For illustration imagine a Portlet called *ExamplePortlet* which was
>  > deployed with image resource */images/r1.gif*. Its consumer-side URL
>  > will look like this:
>  >
> _http://consumer.com/portal/consumer/resources/r1.gif?producerUrl=http://producer.com/portlets/ExamplePortlet/images/r1.gif_
>
>  >
>  >  
>  > If the Portlet has a style sheet resource */css/r2.css*, its URL will
>  > look like this:
>  >
> _http://consumer.com/portal/consumer/resources/r2.css?producerUrl=http://producer.com/producer/resources/r2.css?resourceUrl=http://producer.com/portlets/ExamplePortlet/css/r2.css_
>
>  >
>  >  
>  > Now if r2.css contains a reference to r1.gif, then the producer-side
>  > servlet (producer/resources) will invoke the Producer URL writing logic
>  > for this URL. So eventually the image URL returned to the client within
>  > the style sheet will exactly as in the first example.
>  >  
>  > Regards,
>  > Artem
>  >  
>  >  
>  >
>  > ------------------------------------------------------------------------
>  >
>  > *From:* Rich Thompson [mailto:richt2@us.ibm.com] *
>  > Sent:* Tuesday, March 22, 2005 9:58 PM*
>  > To:* wsrp-interfaces@lists.oasis-open.org*
>  > Subject:* Re: [wsrp-interfaces] Applet resources through WSRP
>  >  
>  >
>  > I have been asked this question now by several people ... has anyone
>  > tried referencing an applet in markup from a WSRP portlet? If so, any
>  > guidelines that should be shared with portlet developers?
>  >
>  > Rich
>  >
>  > *Subbu Allamaraju <subbu@bea.com>*
>  >
>  > 01/26/05 08:07 AM
>  >
>  >                  
>  > To
>  >                  wsrp-interfaces@lists.oasis-open.org
>  > cc
>  >                  
>  > Subject
>  >                  Re: [wsrp-interfaces] Apptel resources through WSRP
>  >
>  >
>  >  
>  >
>  >
>  >                    
>  >
>  >
>  >
>  >
>  >
>  >
>  > Is the Producer returning the Content-Type header? I've not tried applet
>  > downloading, but if Content-Type does not work, I would try the
>  > Content-Disposition header, e.g. with a "inline; filename=foo.jar"
>  > value. In any case, the Consumer has to proxy these headers to the
> browser.
>  >
>  > Regards,
>  >
>  > Subbu
>  >
>  > Klein, Avi wrote:
>  >  > Hi,
>  >  >
>  >  >  
>  >  >
>  >  > I wonder if someone has dealt with fetching of applet as resource.
>  >  >
>  >  >  
>  >  >
>  >  > Whenever rewriting the URL of the applet, the browser fails to
> fetch it
>  >  > since it expects the URL to end with *.jar and not with the
> consumer URL
>  >  > (result of the rewriting).
>  >  >
>  >  >  
>  >  >
>  >  >  
>  >  >
>  >  > Thanks,
>  >  >
>  >  >  
>  >  >
>  >  > Avi.
>  >  >
>  >
>
>