Erwin gave me another great idea from Stump the Panel.

We have a document library with a view using a grouped by.
We would like to make it possible to collapse all expanded records with one click.

As much as I try to avoid jQuery becomming a hammer and seeing everything as a nail, this is one of those prime examples of a simple but elegant solution to close a gap in the List View Web Part functionality.

(UPDATED!).

UPDATE: 1/15/2009 – Larry pointed out that nested groups still tried to trigger even if they were not visible which caused some looping. I added the :visible filter to the selectors for the code snippet which seems to work much better for nested groups.

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
function collapseGroups() {
	$("img[src='/_layouts/images/minus.gif']:visible").parent().click();
}
function expandGroups() {
	$("img[src='/_layouts/images/plus.gif']:visible").parent().click();
}
$(function() {
	var expandAll = "<a href='#' onClick="
		+'"'+"this.href='javascript:expandGroups()'"
		+'"><img title="expand all groups" style="border:none;" alt="expand all" src="/_layouts/images/collapseplus.gif"></a>';
	var collapseAll = "<a href='#' onClick="+'"'
		+"this.href='javascript:collapseGroups()'"
		+'"><img title="collapse all groups" style="border:none;" alt="collapse all" src="/_layouts/images/collapseminus.gif"></a>';
	$("td.ms-toolbar[width='99%']").append(expandAll).append(collapseAll);
});
</script>

Update (7/28/2009):
This version tested with jQuery 1.3.2 and IE8:

<script type="text/javascript">
if(typeof jQuery=='undefined'){
	var jQPath = 'http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/';
	document.write('<script src="',jQPath,'jquery.min.js" type="text/javascript"><\/script>');
}
</script>
<script type="text/javascript">
/*
 * Copyright (c) 2009 Paul Grenier (endusersharepoint.com)
 * Licensed under the MIT (MIT-LICENSE.txt)
 */
$(function(){
	jQuery.groups = {
		collapse : function() {
			$("img[src*='minus.gif']:visible").parent().click();
		},
		expand : function() {
			$("img[src*='plus.gif']:visible").parent().click();
		}
	};
	var expandAll = "<a href='#' onClick="
		+'"'+"this.href='javascript:$.groups.expand()'"
		+'"><img title="expand all groups" style="border:none;" alt="expand all" src="/_layouts/images/collapseplus.gif"></a>',
	collapseAll = "<a href='#' onClick="+'"'
		+"this.href='javascript:$.groups.collapse()'"
		+'"><img title="collapse all groups" style="border:none;" alt="collapse all" src="/_layouts/images/collapseminus.gif"></a>';
	$("table.ms-menutoolbar td.ms-toolbar[width='99%']").append(expandAll).append(collapseAll);
});
</script>