NULL's in AW.Grid

When I receive an object json, result of a consulting Oracle, in which, some fields come with the value NULL, the grid puts values of the previous record in those fields NULL's, which they should appear empty. We were forced to put NVL (function Oracle) changing the fields in emptiness for a space. Is that normal?

Again when I receive an object json, result of a consulting, and I want to select the first row of the grid, the same is unavailable, demanding that us, to click in another row and oh yes it is available the same.

Would you have some please example of putting an image (only image) in the grid in agreement with the value of a column?

I am using the grid ActiveWidgets 2.5.3 Free Trial.

Thanks.

What is normally sent to JSON instead of Oracle NULL value? Is it JavaScript null or something else?

The null of the oracle means no-value and it is equivalent to the null in javascript. To solve that problem we used the function NVL of Oracle, so that the same sent a field with a " " (one space) for string field null and 0 for a numeric field null.