How to set a value in a JQGrid cell based on a condition?

 To set a value in a JQGrid cell based on a condition, you can use the cellattr function in the colModel option of the JQGrid.

Here's an example of how you can do this:

javascript
$("#grid").jqGrid({
   // other JQGrid options here...
   colModel: [
      // other column options here...
      {
         name: 'columnName',
         index: 'columnName',
         width: 100,
         formatter: 'text',
         cellattr: function(rowId, val, rawObject, cm, rdata) {
            if (rawObject.columnName == "someValue") {
               return 'style="color:red"'; // set cell color to red
            } else {
               return ''; // default cell color
            }
         }
      }
   ]
});

In this example, we're setting the cellattr option for the columnName column. Inside the cellattr function, we're checking if the value of the columnName cell is equal to "someValue". If it is, we're returning the style attribute with a value of "color:red", which will set the cell's text color to red. If the value of the columnName cell is not equal to "someValue", we're returning an empty string, which will set the default cell color.

You can modify the cellattr function to set the value of the cell instead of its style. For example, you could replace 'style="color:red"' with 'title="some tooltip"' to set a tooltip for the cell.