[B2] Extendable TableChunker?

[stevil]

I'm trying to create my own TreeView, so that I can add my own classes to the markup (for example, I need to get tree-depth-specific classes onto the rows). I've put a collectData method into my TreeView to put the node's depth onto the record, and all I need to do is get that into the template for the view.

From what I can tell by debugging it, I need my own chunker that I can pass in the config to MyTreeView -> TreeView -> TableView, so that I can define my own metaRowTpl, so that the upstream TableView can construct the template for my items.

Problem is, the only chunker implementation is Ext.view.TableChunker, and it's a singleton. I can't seem to extend the class, as it's a singleton. That would seem to be by design, and it's not a bad one.

(Edit: Seems from other posts, I can extend by using Ext.getClass() on the singleton. Ok, that would seem to work, but isn't that a little bit hacky? (in order to extend a class, I need to drill into its definition to find out if it's declared as a singleton, and then extend or override that way?) Also, I would have to use Ext.extend (Ext.getClass(...)...) instead of Ext.define ({ extend...}), which is less nice.)

In that case, to make my own chunker, I need to copy the whole TableChunker implementation and define my own with the metaRowTpl I need. I clearly prefer not to do that just to get my own metaRowTpl definition inserted into the chain.

I'd like to suggest one of the following as regards Ext.view.TableChunker:

1. Refactor into an AbstractChunker which the TableChunker singleton extends (and therefore so can I)
2. Take the singleton property off the TableChunker class (what is the benefit of that here?)
3. Tell me how I'm doing this wrong

stevil