Content selection expressions

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Content selection expressions

JOSE MANUEL CANTERA FONSECA

Dear all,

Does the current version of the content selection  standard allow to
include expressions in other languages than XPATH?  I'm thinking in
expressions expressed in Expression Language (JSP 2.0) for example.

Thanks and Best Regards

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RE: Content selection expressions

Rotan Hanrahan

DISelect only specifies XPath. Keeping the technology within the scope of existing W3C technologies. Binding to EL is certainly a possibility. MobileAware has its own expression binding for a thematically similar technology, so we know from practical experience this is possible. From a high-level point of view, what is important is the ability to use selection within the content, so that the selection expressions can capture in some way the presentation requirements of the author. It is certainly within the philosophy to consider similar approaches in other domains. But mixing them might be a struggle. A DISelect processor that accepted EL instead of XPath would have additional features (such as bean access) and limitations (such as DOM access).

In terms of DISelect as specified, XPath is the language you use, and you can extend it to provide access to other contextual data if needed. For example, when DDWG eventually produces a vocabulary, someone could create an XPath binding to those properties so that DISelect would be able to use DDR data. (Yes, I think someone will implement that...)

I'm not tending one way or the other. Let's just see what evolves.

---Rotan.

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of José Manuel Cantera Fonseca
Sent: 18 October 2006 15:59
To: [hidden email]
Subject: Content selection expressions


Dear all,

Does the current version of the content selection  standard allow to include expressions in other languages than XPATH?  I'm thinking in expressions expressed in Expression Language (JSP 2.0) for example.

Thanks and Best Regards


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RE: Content selection expressions

Rhys Lewis
In reply to this post by JOSE MANUEL CANTERA FONSECA

Hello Jose,

Interestingly this is not the first time that DI has been asked about the possibility of using DISelect with other expression languages. I have some sympathy for this, given how awkward XPath expressions look inside XML documents.

Personally, I have no problem with enabling other expression languages for DISelect. The base reason for picking XPath initially was because it is what is used elsewhere in DIAL, in particularly in XForms. Hence, it makes perfect sense for that to be the expression language for DISelect used in DIAL. This is not necessarily the case in other potential uses of DISelect.

Right now, there is no particular group within DI pressing for additional expression languages, so its not likely to happen spontaneously. However, if W3C member companies wish to join DIWG, or its follow on after rechartering, to carry that work forward, I think that it could be easily accommodated in a future revision of DISelect.

By the way, I assume by JSP 2.0 you mean using those expressions in-line rather than embedding DISelect in a JSP or servlet. In that latter case you can, of course, already do this. I know I have!

Best wishes
Rhys

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of José Manuel Cantera Fonseca
Sent: 18 October 2006 15:59
To: [hidden email]
Subject: Content selection expressions


Dear all,

Does the current version of the content selection  standard allow to
include expressions in other languages than XPATH?  I'm thinking in
expressions expressed in Expression Language (JSP 2.0) for example.

Thanks and Best Regards



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Re: RE: Content selection expressions

JOSE MANUEL CANTERA FONSECA
Yes I was thinking in using the E.L syntax. Actually we use it in
MyMobileWeb for specifying declarative data binding and some dynamic
aspects of the "declaratively specified" mobile presentation layer.

Thanks one more time

Best Regards

----
José Manuel Cantera Fonseca
Telefónica I+D

----- Mensaje original -----
De: Rhys Lewis <[hidden email]>
Fecha: Miércoles, Octubre 18, 2006 6:22 pm
Asunto: RE: Content selection expressions
Para: "José Manuel Cantera Fonseca" <[hidden email]>, "[hidden email]"
<[hidden email]>

>
> Hello Jose,
>
> Interestingly this is not the first time that DI has been asked
> about the possibility of using DISelect with other expression
> languages. I have some sympathy for this, given how awkward XPath
> expressions look inside XML documents.
>
> Personally, I have no problem with enabling other expression
> languages for DISelect. The base reason for picking XPath initially
> was because it is what is used elsewhere in DIAL, in particularly
> in XForms. Hence, it makes perfect sense for that to be the
> expression language for DISelect used in DIAL. This is not
> necessarily the case in other potential uses of DISelect.
>
> Right now, there is no particular group within DI pressing for
> additional expression languages, so its not likely to happen
> spontaneously. However, if W3C member companies wish to join DIWG,
> or its follow on after rechartering, to carry that work forward, I
> think that it could be easily accommodated in a future revision of
> DISelect.
> By the way, I assume by JSP 2.0 you mean using those expressions in-
> line rather than embedding DISelect in a JSP or servlet. In that
> latter case you can, of course, already do this. I know I have!
>
> Best wishes
> Rhys
>
> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On
> Behalf Of José Manuel Cantera Fonseca
> Sent: 18 October 2006 15:59
> To: [hidden email]
> Subject: Content selection expressions
>
>
> Dear all,
>
> Does the current version of the content selection  standard allow to
> include expressions in other languages than XPATH?  I'm thinking in
> expressions expressed in Expression Language (JSP 2.0) for example.
>
> Thanks and Best Regards
>
>
>
>

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