Combo performance patch for IE

I while ago I noticed a serious performance issue when running in IE6 SP3:

Add, say, 3000 options into the combobox.
Then scroll down to the last few options and hover the mouse over a few of the options so that it selects them. IE slows down to a crawl.

I fixed this using the attached patch. The patch basically caches the option position so that it doesn’t have to loop through all of the options every time.

Please consider adding my patch to the core code so that I can stop updating it myself. (1.31 KB)

The loop through all nodes is rather fast operation. And there should be no problems with it even in a combo with many options.

However, we’ll consider your solution and possibly add it into official version.

The fact is that IE6 does it extremely slowly. You can’t state that something is fast when it isn’t.

Test it in IE6 and see for yourselves.

We’ll check and possibly add your solution. However, we have not got complains similar to yours before.

For the comboboxes with many options we would recommend to use dynamic filtering. It’ll decrease loading and rendering time: … ilter.html … ig_db.html

Thanks for the suggestion - I considered dynamic loading but the users need to scroll through the list to find what they need so that won’t help me.

Of course, ideally, I wish for a similar enableSmartRendering feature as in your grid: to dynamically load the options from memory as they scroll down. But in the meantime I make do with what I have.