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RE: Binding

From: Belov, Alexey <Alexey.Belov@scala.ru>
Date: Thu, 19 Apr 2001 03:14:36 -0400 (EDT)
Message-ID: <C7D6AEA730D1D111BFC50060083DD49A862BA0@hermes.scala.ru>
To: "'www-forms@w3.org'" <www-forms@w3.org>
	Hi Micah,

	Thank you for the attention to my problem. I really appreciate it !
	Yes, it can be done like this. But now I have some new questions:

	1) Where is the binding between the form control and model item ?
	2) What if I want to have one model and several UI descriptions
	with controls bound to overlapping subsets of items in this model,
or vice versa ?
	In this case, binding between instance data and model items
	through form controls only becomes difficult and very uncomfortable
	for developer.
	3) How can I give the UI customization possibility to the client ?
	I mean the situation, when he can change layout, 
	i.e. move, group and even remove available controls, but can not
change
	their behaviour (model).

	My personal opinion, that the link DATA - MODEL - UI more natural
than
	DATA - UI - MODEL. Especially, with regard to the main idea stated
	in W3C working draft about one XML instance data, one XForms Model
	and many different UI descriptions for different devices. 

	What do you think about that ? Are there any discussions on this
question in W3C ?

	Best regards,

		Alexey


-----Original Message-----
From: Micah Dubinko [mailto:MDubinko@cardiff.com]
Sent: 18 ?????? 2001 ?. 23:33
To: 'Belov, Alexey'
Cc: 'www-forms@w3.org'
Subject: RE: Binding


Hi Alexey,

Let's say your desired instance data looked like this:

<Envelope>
  <name>...</name>
  <salary>...</salary>
  ...
  <access>manager</access>
</Envelope>

For this example, I added an extra tag, <access>. This might be considered a
"hidden" field--it exists in the instance data, but will never show up in a
form control. This would be generated by the buisiness logic on the server
prior to XForms processing the instance data.

SECURITY NOTE: For some pieces of sensitive data, like <salary>, it might
not be sufficient to just instruct the form not to show it. It would be
advisable to only send this data on a 'need-to-know' basis, over a secure
connection.

Now, take for instance an XForms form control to be used to edit the
<salary>. Use...

A binding expression of ref="Envelope/salary" to refer to the correct
location in the instance data.

A model item property of relevant="Envelope/access is 'manager'" to make
sure only those with "manager" access can change this field. A similar logic
applies to the roles of "assistant" or "junior" or any others.

Please don't take the exact syntax here literally -- our upcoming drafts
will revise and improve this aspect.

Thanks!

Micah J. Dubinko, CDIA
Senior Engineer
Chief XML Architect
http://www.Cardiff.com/


-----Original Message-----
From: Belov, Alexey [mailto:Alexey.Belov@scala.ru]
Sent: Wednesday, April 18, 2001 5:47 AM
To: 'www-forms@w3.org'
Subject: Binding


	Dear All !

	I liked the working draft for XForms very much: a lot of brilliant
ideas are in there.
	But some things important for me are not clear, especially the
binding between
	XForms Model and XML instance data.

	Let's look at the following example: 
	1) I receive an XML from my business logic object with ALL the data
for Employee: 
	Code, Name, Address, Salary, Bonus Percent, etc;
	2) I have three users working with my system: HR Manager can enter
new Employees
	and adjust all the information for existing ones; HR Manager
Assistant can select 
	existing Employees, see their Codes and Names and adjust Address
only; 
	Junior Accountant can adjust only Bonus Percent for existing
Employees;
	3) So, I want to have three XForms Models for these guys with
different values of 
	ReadOnly, Relevant, Required and Validate properties
	for the same Model Elements bound to the same XML data.
	4) PROBLEM: There is no binding possibility between XForms Model and
XML data !!!

	Could somebody of You propose some solution or inform me about the
latest
	W3C decisions on this problem. Thank You in advance !

	Best regards,

		Alexey
Received on Thursday, 19 April 2001 08:18:42 GMT

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