The DataTransfer.mozSetDataAt() method is used to add data to a specific index in the drag event's data transfer object.

A data transfer may store multiple items, each at a given zero-based index. mozSetDataAt() may only be called with an index argument less than mozItemCount in which case an existing item is modified, or equal to mozItemCount in which case a new item is added, and the mozItemCount is incremented by one.

Data should be added in order of preference, with the most specific format added first and the least specific format added last. If data of the given format already exists, it is replaced in the same position as the old data.

The data should be either a string, a boolean value or number type (which will be converted into a string) or an nsISupports.

type

A string representing the type of the drag data to add to the drag data object.

data

A nsIVariant representing the data to add to the drag data object.

index

A unsigned long representing the index of the data to add.

None.

This example shows the use of the mozSetDataAt() method in a dragstart handler.

function dragstart_handler(event)
{
  var dt = event.dataTransfer;
  var idx = dt.mozItemCount;
  // Add two new items to the drag transfer
  if (idx >= 0) {
    dt.mozSetDataAt("text/uri-list","http://www.example.com/", idx);
    dt.mozSetDataAt("text/html", "Hello World", idx+1);
  }
}

This method is not defined in any Web standard.

• Drag and drop
• Drag Operations
• Recommended Drag Types
• Dragging and Dropping Multiple Items
• DataTransfer test - Paste or Drag