Accessing cells

I have a TreeGrid that uses a split. I need to loop through every row / every cell in the main part of the grid and set the values of each cell. Right now, I’m finding that  this.cells (row_id,col) only works if I have already selected a cell and put it into edit mode. If I just try to use this.cells(row_id, col) with out going into edit mode, I eventually get an error because this.getRowById(row_id) returns a TR node with no Children…which then causes this.cells4(cell) to fail because cell is null. 

Is this the way the this.cells calls are supposed to be? Or am I doing something else wrong here?  Or, is there another way for me to do access cells with out having to go into edit mode?

Thanks.

The code construction
    grid.cells(i,j)
must for for any row, but it will not work in cases when row not parsed yet

- smartRendering - row not loaded or not parsed
- dynamical loading, paging - row not loaded or not parsed
- smartXMLParsing - row not parsed ( all initially closed branches )

In all mentioned modes not rendered row stored as description only, and can’t be used by API