Viz Data Format

Viz Data Format is a proprietary format used to package Escenic content for delivery by the Content Engine's web service.

The VDF format in general allows for a document to contain either a model, which describes the structure of the data contained in another VDF document, or a payload, which contains actual data. This provides applications using the format with a means of understanding and handling new types of data.

The Content Engine's web service, however, currently only makes use of the payload format, which means that client applications must know the structure of the data in any content items downloaded from the web service. For a Content Engine web service client this is not really a problem, since the structure of all content items is also defined in a Content Engine content-type resource (see content-type).

The following example shows the general structure of the VDF documents returned by the web service:

<vdf:payload xmlns:vdf="http://www.escenic.com/types" 
             model="http://nightly.dev.escenic.com/webservice/content-descriptions/news">
  <vdf:field name="SUMMARY">
    <vdf:value>
      <div xmlns="http://www.w3.org/1999/xhtml">
        <p>Some XHTML content</p>
      </div>
    </vdf:value>
  </vdf:field>
  <vdf:field name="BODY">
    <vdf:value>
      <div xmlns="http://www.w3.org/1999/xhtml">
        <p>Some more XHTML content</p>
      </div>
    </vdf:value>
  </vdf:field>
  <vdf:field name="SCOREBOOST">
    <vdf:value>C</vdf:value>
  </vdf:field>
  <vdf:field name="OPTIONS">
    <vdf:list>
      <vdf:payload>
        <vdf:field name="OPTIONS">
          <vdf:value>C</vdf:value>
        </vdf:field>
      </vdf:payload>
    </vdf:list>
  </vdf:field>
</vdf:payload>

The root element is always a payload element. The individual elements are described in the following sections.