Hi Leo,

I think you get it. As I said earlier, this template was extracted from more complex code. For the reasons you've been finding, perhaps it isnt the best example. The 'l' makes sense in the context where this template came from. Your replacement with 'this' is probably going to be correct.

The best way to approach this sort of problem is usually to see what template the Ext component you are extending uses by default. These templates frequently change between Ext revisions. Assuming you are using Ext3, you can find it here:

http://docs.sencha.com/ext-js/3-4/source/Combo.html#Ext-form-ComboBox-cfg-tpl

That is the template on which my example is based. You'll see that the example takes the Ext code and augments with additional options. To make an Ext4 version, you would use a similar approach.

To your first question: displayColumn and lookupColumn are attributes on LabKey Field metadata objects. See our docs on LABKEY.Query.FieldMetaData for more. In your example, you probably want to be using the Combo's displayField / valueField properties. That's what Ext's default template does.