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Re: Standard Component Descriptions

From: Alessandro Vernet <avernet@orbeon.com>
Date: Wed, 15 Nov 2006 18:26:09 -0800
Message-ID: <4828ceec0611151826t3f0588a6u4ef58f2ab86ed13c@mail.gmail.com>
To: public-xml-processing-model-wg <public-xml-processing-model-wg@w3.org>

Alex,

My comments about the proposed standard component library:

On 11/9/06, Alex Milowski <alex@milowski.org> wrote:
> 1.4. [p:]serialize
>
> The [p:]serialize component applies XML serialization to the
> children of the document element and replaces those children
> with their serialization.  The outcome is a single element with
> text content that represents the "escaped" syntax of the
> children if they were serialized.

What would be the qname of that root element? In Orbeon Forms (which
used to be called Orbeon PresentationServer or OPS), the component
that serves the same purpose as p:serialize is called
oxf:xml-converter and it generates a root element as follows:

<document xsi:type="xs:string" content-type="application/xml;
charset=iso-8859-1">

The benefit of indicating the type this way is that you can extend
this to handle binary data encapsulated in XML (with
xsi:type="xs:base64Binary"). Then given a <document> another component
has all the information it needs to say store it in a file on disk or
sent it in an HTTP response. More on binary documents:

http://www.orbeon.com/ops/doc/reference-formats

Also, we might want to have more parameters on p:serialize. See for
instance how the equivalent component in Orbeon Forms can be
configured:

http://www.orbeon.com/ops/doc/processors-converters#d12e74

> 1.5. [p:]parse
>
> [...]
>
> When the text value is parsed, a document element wrapper should be
> assumed so that element siblings can be parsed back into XML.

Do we need this wrapper element? Are the use cases that call for a
wrapper element frequent enough that we are willing to pay the cost of
the added complexity here? To me, adding a wrapper element looks
orthogonal to parsing.

> 2.1. [p:]xquery
>
> The [p:]xquery component applies a query to a collection and
> provides the result of the query as its output.

How is the XQuery expression come in the 'input' document?

> 2.3. [p:]validate

Should this component be called p:xml-schema-validate, if it performs
only validation with XML Schema? Or is your intention to extend the
component later to allow for other schema languages such as Relax NG
to be used?

> 2.5. [p:]url-action

This is incredibly useful, but I am afraid that we are opening a can
worms by trying to specify this now. Also note that this is somewhat
similar to the XForms's <xforms:submission>. I would prefer not to
include this component for now. If we think that the use cases calling
for this component are too important for us to ignore this, I would
try to reuse the XForms submission.

The submission element in XForms 1.0:
http://www.w3.org/TR/xforms/slice3.html#structure-model-submission

Additions in XForms 1.1 (working draft):
http://www.w3.org/TR/xforms11/#submit

Alex
-- 
Blog (XML, Web apps, Open Source):
http://www.orbeon.com/blog/
Received on Thursday, 16 November 2006 02:51:38 GMT

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