Add new datagridRow, sort the datagrid and give serial numbers, in FLEX

Question

Hi,

I have a datagrid. I add a row to the datagrid using an ADD button. Once I add, I sort the datagrid based on a column. I also provide the serial numbers i.e. row numbers as first column to the datagrid. But, the serial number function does not apply after sorting. Hence, a new row added for e.g. row 5, based on sorting should be row 1, the serial number displayed is still row 5. The UI looks bad as numbers are not in correct order. the code is :

// Sorting Function :

  private function sortGrid():void 
  {
        sortGridColl = new ArrayCollection(sortGridArray);
            sortA = new Sort();
            sortByLevel = new SortField("Type", true, false);
            sortA.fields=[sortByLevel];
         sortGridColl.sort=sortA;
         sortGridColl.refresh();
         sortGrid.dataProvider=sortGridColl;
    sortGrid.rowCount=myDPColl.length +1; 
  }        

// Serial Number function :

private function sortGridSerialNumbers(oItem:Object,iCol:int):String
{
         myDPColl = new ArrayCollection(sortGridArray);
        var iIndex:int = myDPColl.getItemIndex(oItem) + 1;
        return String(iIndex);
}

// Adding new row to datagrid :

sortGrid.dataProvider.addItem
(
{
    Type : typeName.text
}
);

Answer 1

Is sortGridSerialNumbers supposed to return the current serial numbers after sorting? Because it seems to only display the serial numbers for your original state. It won't give the correct value for any item that was added since you added the item to the dataProvider, not the original array.

Answer 2

I like arrays better than array collections, so my choice would be to maintain the list as a raw array. Then on each add, push the new element, do a sortOn (myArray.sortOn("Type")), then iterate over all items to adjust the serial number. Then apply the array to the datagrid as a new dataprovider.