Flex :: Intercept Value Passed To Item Editor?

I'm trying to intercept the value that is taken from a DataGrid's GridColumn's itemRenderer and applied to the itemEditor, and vice-versa. I need to be able to format this value. However, my project is complex, so I may be focusing on the wrong idea in what I'm trying to accomplish.

I have a Spark DataGrid component (with ID dg) that I am dynamically populating from XML. I create an ArrayCollection from some nodes, and a regular Array from sub-nodes that is added as a property of the ArrayCollection. That ArrayCollection is then used as the dataProvider for the DataGrid.

Here is an example segment of a typical XML node and it's sub-nodes:

<item name="physOrderTable" text="" type="notes">
<cols>
<col id="0" text="Day/Time" />

[Code].....

This is the only method I've been able to use to achieve the desired result. This all works fine, if all I want to do is merely display information. But I need to be able to edit the values in each cell, and apply this back to the dataProvider, as I need to rebuild XML with the updated values later.

I have tried everything I can possibly think of to be able to do this. I built my own itemRenderer, then my own itemEditor, then scrapped them because it felt like I was re-inventing the wheel. But was I? I tried reading through the code for the DataGrid, GridColumn, and related classes, but I couldn't find any reference to the itemEditor beyond it being an IFactory. I have no idea where or how it tells that IFactory to be a text input or whatever it is.

Here is my issue:

When I turn on the DataGrid's editing, and double-click a cell, it takes the entire array of the col dataField for that column's cell, converts that array to a string, and displays the entire string in the edit text box. If I cancel the editing, or save the editing, it sets the string to the .col property. Then the labelFunction tries reading that string as an array, and it crashes. I was able to get the typeof the col dataField and converting it to an array if it's a string, but I shouldn't have to.

I need to have it display just the value of the cell for that particular row and column when the instance of the itemEditor is created. When that value is changed, I need it to apply back to that column's index in the .col array of the dataProvider. So, similarly to how it displays information in the labelFunction, I need to edit the information and send it back.

I've seen lots of custom itemEditors and itemRenderers for GridColumns, but these are hard-coded in the MXML. My grid is almost entirely dynamically created, so that's unfortunately not an option for me, as I won't even know how many columns or rows there will be when the DataGrid is created. I tried using rendererIsEditor, but that only seems to be on the MXML instantiation of the GridColumn, as there's only rendererIsEditable in the ActionScript, and it doesn't seem to work (or I don't know how to use it as intended).