ChannelDefinitionFormat

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MicroSoft's addition to InternetExplorer (from 4 onwards) to allow website coders to syndicate their content directly to IE, thus allowing users to keep track of the lastest website changes (ChangeAggregator), it is also an example of PushTechnology?.

CDF is a subset of the ExtensibleMarkupLanguage (XML) and is an OpenStandard?, which [Microsoft has submitted] to the WorldWideWebConsortium.

In it's simplest form a CDF channel is used purely for HeadlineSyndication (similar to ResourceDescriptionFramework / RichSiteSummary). In it's more complex format it can update software, use your website as a ScreenSaver? on a user's Windows DeskTop?, and allow the user to view your website off-line. It's a 'TV' idea transferred to the web.

It adds the website channel into IE's favourites, which can also be viewed as an InternetExplorerSidebar, and whenever the favourite is accessed it displays a list of the recent headlines from the webpage. A schedule (update daily, weekly, etc) can be set within the CDF file itself. It is also possible to create a PersonalizedChannel? for users as well, easier to do if you are coding in Wiki:ActiveServerPages (ASP).

The downside, unlike RDF/RSS, is that CDF can only, as far as I am aware, be viewed in InternetExplorer, thus the information cannot be syndicated, and viewed, on a website directly, unlike RDF/RSS. But, using XML / XSLT and, in my own case, ASP, it is easier to create a single .asp page which will automatically detect which browser is being used (MozillaBrowser, InternetExplorer or OperaBrowser), and create syndicated information in the desired format on the fly.

Example code for a CDF file - using MeatBall RecentChanges:

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

<channel prechache="no" level="0" href="http://www.usemod.com/cgi-bin/mb.pl?RecentChanges" base="http://www.usemod.com/cgi-bin/mb.pl" self="?RecentChanges">
<logo href="http://www.edazzle.net/meatball.gif" style="icon"/>
<title>Meatball Wiki Recent Changes</title>
<item href="http://www.usemod.com/cgi-bin/mb.pl?InternetExplorerSidebar">
<title>InternetExplorerSidebar</title>
<log value="document:view"/>
</item>
<item href="http://www.usemod.com/cgi-bin/mb.pl?WikisWithLinkDatabases">
<title>WikisWithLinkDatabases</title>
<log value="document:view"/>
</item>
<item href="http://www.usemod.com/cgi-bin/mb.pl?StructuralConflict">
<title>StructuralConflict</title>
<log value="document:view"/>
</item>
</channel>

The MimeType? for a CDF file is 'application/cdf'

ChannelDefinitionFormat

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