Pass NewItem ID to Callback function from NewItem form

Question

I have a rigged a link to call the NewItem.aspx form in a dialog. When the User clicks 'Save', I would like to return the new item ID in the callback function. How is this achievable?

<a href='javascript:openDialog()'>New Item</a>

function openDialog(test) {

var options = {
        title : "New Item",
        url : "/_layouts/BRP_CustomWelcome/DialogLocation.aspx",
        dialogReturnValueCallback : dialogCallback,
    };

SP.UI.ModalDialog.showModalDialog(options);
}


function dialogCallback(dialogResult, returnValue) {

  if (dialogResult == SP.UI.DialogResult.OK)
  {
      var id = returnValue; //HOW DO I GET THE NEW ID HERE?!
      customJSFunction(id);
  }
}

Answer 1

First get the Id of the item, then on click of Save button, close the dialog box and pass Id as the parameter:

//Logic for getting Id
SP.UI.ModalDialog.commonModalDialogClose(SP.UI.DialogResult.OK, Id);