Data binding XML to a form

23 October, 2007 - 22:28 — Richard

It is often useful to load some XML data, place it into a form, save changes back to the XML document as they are made in the form, and post the XML back to the server.

Having loaded some XML into a global variable $userProfile:

<?xml version="1.0" encoding="UTF-8"?>

<UserProfile>

        <Name first="Roger" surname="Rabbit" />

        <Demographics age="25" />

</UserProfile>

we want to bind a field to an element in the XML document using an xpath:

<input type="text" id="firstName" 

    path="$userProfile/Name/@first" e:behavior="l:autofill" />

When the field value changes, the XML attributes are updated. Here is the behavior:

<d:tdl>

  <d:namespace name="http://www.backbase.com/2007/labs">

    <d:behavior name="autofill">

      <d:attribute name="path" />

      <d:handler event="populate" type="application/javascript">

        var path = bb.command.getAttribute(this, 'path');

        this._data = bb.evaluateSmart(path, bb.document)

        var sFirst = this._data.value;

        bb.setProperty(this, 'value', sFirst);

      </d:handler>

      <d:handler event="change" type="application/javascript">

        this._data.textContent = bb.getProperty(this, 'value');

      </d:handler>

    </d:behavior>

  </d:namespace>

</d:tdl>

This is very basic proof of concept code (attached). To do:
* handle updating attributes and element text content
* handle binding for elements that do not have a 'value' property

Attachment	Size
dataform.zip	2.03 KB

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Comments

Thanks Richard for this

31 October, 2007 - 14:49 — Paweł Katarzyński

Thanks Richard for this post, it helped a lot as in my case, XML in and XML out is most desired behavior for my forms (I'm using eXist XML database). Do You intent to build-in more general mechanism for XML databinding in the future releases of Backbase?

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