Item renderer - Rendering a row in flex

Question

I have got a datagrid with three columns. I have applied two different renderers on different columns (Say Renderer A at column 1 and Renderer B at column 3).

Now in set Data() of B (column three's renderer) I am changing a Requiredflag on the basis of some condition. In set Data of A (Column 1's renderer), I am checking the RequiredFlag and changing its style accordingly.

The problem is for a Row, A renders before B as it is the first column, so it does not get the updated value of requiredFlag (as the requiredFlag is updated in B).

So can I somehow render the first column's cell again after rendering third column's cell? Or if I can render the whole row again after the value of requiredFlag changes in third column's cell.

Because of this, my first column's cell's style doesn't comes in sync with the third columns's requiredFlag value :( — Nirjhar Dave
Ok a rule of thumb to follow let the renderers do the rendering not data manipulation. Think of a renderer as a view. So with that in mind do the update to the data provider before you update the datagrid. — The_asMan
do you mean renderer B will change the dataProvider?refresh dataprovider will be ok. So "requiredFlag" or "style" should be part of dataProvider, then they can be updated when datasource changed. — simmone

Marcx Marcx · Accepted Answer · 2012-10-24T09:05:34

See the itemrender as a view, so the renderer itself does not do any computation, just check the value of the object...

If I understood correctly I'll do something like that...

(maybe you need to move the check from set data to updatedisplaylist)

example:

class Test
{

   public var col1:String = "Everything";
   public var col3:String = "Cars";

   public function get color():uint
   {
     if (col1 == "Everything")
       return 0xff0000;

     return 0x000000;
   }

}

itemrendererA.mxml

override public function set data(value:Object):void
{
   super.data = value;
   if (super.data != null && super.data is Test)
   {
      // do what you need to do..
      lbl1.text = (super.data as Test).col1;
      lbl1.setStyle("color", (super.data as Test).color);
   }
}

itemrendererB.mxml

override public function set data(value:Object):void
{
   super.data = value;
   if (super.data != null && super.data is Test)
   {

      if ( (super.data as Test).color == 0xff0000)
         // do something
      else
        // do something else
   }
}

if that's not what you're looking for, please add some of your code...

Item renderer - Rendering a row in flex

1 Answers