Extension to createTagButton

[tb]

With the following change tag buttons could indicate whether a tag is being used or not.

function createTagButton(place,tag,excludeTiddler,title,tooltip){ 
var btn = createTiddlyButton(place,title||tag,(tooltip|| 
config.views.wikified.tag.tooltip).format([tag]),onClickTag);

//NEW CODE 
addClass(btn,store.getTaggedTiddlers(tag).length>0?'hastags':'hasnotags');
//DONE 

btn.setAttribute("tag",tag); 

if(excludeTiddler)btn.setAttribute("tiddler",excludeTiddler); 
return btn; 
}

See related discussion...  http://groups.google.com/group/tiddlywikidev/browse_frm/thread/0511c3236e475789

[FND]

From that thread:

Two concerns:
a) performance - we'd need to do some profiling to ensure there's no significant impact here
b) each such button would have to be refreshed [via config.refreshers] when any tiddler is modified