Using DataTableScreen - Tried to delete row with on_cell_deleted but couldn't

[jr180180]

Hey RedPotion team! I'm not sure if this is an issue. Could be an opportunity to enhance RedPotion.

Going through the getting started tutorial, I created a DataTableScreen with a CDQ Model. When I tried deleting a row, it wouldn't allow me to do so using the on_cell_deleted method. I couldn't access the CDQ methods from within that method.

I posted about this in the RubyMotion forum.

Within my controller, I had to use delete_row instead:

def delete_row(index_path)
    @names.all[index_path.row].destroy
    cdq.save #  you need to call this for persistance purposes
end

If that's actually how it's suppose to work or if you have any advice on this, please let me know. :+1:

Thanks a ton!

[markrickert]

Yes. That's how it's supposed to work. Basically you need to delete the object from the database with the on_cell_deleted method but return false so the table view doesn't try and delete the cell, the database sends a notification that the table listens to when it's delete. Returning false from that method basically tells the table that it's not allowed to delete the row.

[jr180180]

Ahhh, gotcha. I think I understand now.

You're saying I could have written it like:

  def on_cell_deleted(cell)
    @names.all[cell[:arguments][:id]-1].destroy
    cdq.save

    false
  end

and it would skip this part, right?

        unless delete_cell == false
          self.promotion_table_data.delete_cell(index_path: index_path)
          deletable_index_paths << index_path
        end

Looks like when I tried that the first time around, I forgot to return false. Stupid me. :(

[markrickert]

You got it. That should work for deleting rows.

[jr180180]

Thanks for your help here, @markrickert ! Really appreciate it.

I love how this works so freakin' well!

For others reading this, I originally created an id argument in my model

 def cell
    {
      # Use the model's properties to populate data in the hash
      title: name,
      subtitle: "Something else: #{something_else} - #{id}",
      action: :msg,
      editing_style: :delete,
      arguments: {id: id}
    }
  end

and used that for the on_cell_deleted above.

Hence:

@names.all[cell[:arguments][:id]-1].destroy

Turns out, the id argument isn't even necessary. You can pass a second parameter index_path into your on_cell_deleted method and easily remove the row with that. So much easier then trying to make sure you're creating unique IDs for your rows. :)

Here's what you can use instead:

  def on_cell_deleted(cell, index_path)
    @names.all[index_path.row].destroy
    cdq.save

    false
  end

_High Fives to gem authors_ :hand:

Hope this thread helps someone!