CDF Reference for Active Channels

The following section describes the suggested revision to Channel Definition Format (CDF) that Microsoft and other partners are presenting to the W3C (World Wide Web Consortium). For reference purposes, this revision is CDF version 0.4. CDF is an application of the Extensible Markup Language (XML). The original submission of CDF to the W3C can be found at http://www.w3.org. 

• CDF Syntax
• CDF Elements

CDF Syntax

Note that the syntax might vary for different elements. The following table describes the possible formats in which the tags might appear.

<ELEMENT ATTR1="value" ATTR2="value"/>

<ELEMENT>Element Content Here</ELEMENT>

<PARENT ATTR1="value">
	<CHILD1>
	    Content
	</CHILD1>
	<CHILD2 ATTR1="value"/>
</PARENT>

CDF Parsing Rules and Hints

To avoid some common mistakes, keep the following rules in mind when creating a CDF file.

Special Characters	When placing text content between an element start and end tag, you must encode the following characters to prevent CDF parsing errors. Character Encoded value < &lt; > &gt; ' &apos; " &quot; & &amp; For a complete list of other named character set entities, see the documentation on HTML Character Sets (Charsets) and Named Entities.
Character Encoding	The CDF file supports encoding for any ASCII character with the format &#nnn. For example, the ampersand character could also be encoded with its ASCII decimal value of 38 by using the string &#038.
Attribute Syntax	All attribute values must be enclosed in quotation marks, even if the value is a number.
Comments	Any text you want to be ignored by the CDF parser should be placed between the comment start tag (<!--) and the comment end tag (-->).

CDF Elements

This section describes the elements and associated attributes used to create Channel Definition Format (CDF) files for Active Channels. Some CDF files may be used for other types of Webcasting, such as Active Desktop items and Software Update Channels, depending on the value of the USAGE element.

?XML	A	ABSTRACT	CHANNEL
EARLIESTTIME	HTTP-EQUIV	INTERVALTIME	ITEM
LATESTTIME	LOG	LOGIN	LOGO
LOGTARGET	PURGETIME	SCHEDULE	TITLE
USAGE