Mura CMS : This is an example of how to dynamically populate an extended attribute select menu/selectbox based on a Mura Content Collection / Local Index.

muraDynamicExtendedAttributes.cfc

<cfscript>
component extends="mura.cfobject" output="false" {

  // Drop the methods below in your theme or site contentRenderer.cfc

  // This example assumes you wish to populate the Label with the content Title, and the value stored would be the URL
  // With the methods defined below, you should be able to add the following into your extended attribute fields:
    // Option List:  [mura]$.getSpeakersOptionList()[/mura]
    // Option Label List:  [mura]$.getSpeakersOptionLabelList()[/mura]

	// SPEAKERS

		// getSpeakersOptionList (value stored by Mura)
		public any function getSpeakersOptionList() {
			var it = getSpeakersfeed().getIterator();
			var item = '';
			var optionList = '';

			While(it.hasNext()) {
				item = it.next();
				optionList = ListAppend(optionList, item.getURL(), '^');
			};

			return optionList;
		}

		// getSpeakersOptionLabelList (label displayed to User)
		public any function getSpeakersOptionLabelList() {
			var rs = getSpeakersFeed().getQuery();
			return ValueList(rs.title,'^');
		}

		// getSpeakersFeed (assumes you have a pre-defined feed/content collection named 'Speakers')
		public any function getSpeakersFeed(feedName='Speakers') {
			return variables.$.getBean('feed').loadBy(name=arguments.feedName);
		}

		// @END Speakers

}
</cfscript>

This saved our lives! Thanks so much!