batch processing not working in my custom component.

I added batch processing to custom components on a blog overview page.

Ik used the code i found here: https://community.khoros.com/t5/Developer-Discussion/batch-processing-checkbox-in-custom-components/m-p/278831

The checkboxes show correctly when the batch processing is enabled. When i try to delete multiple items and haven't selected any checkboxes I get an error message saying i didn't select any items.
When I select the checkbox(es) and klik delete the selected items, no error displays but the delete function (or any other function) doesn't get triggered.

But it does recognize the fact that i did or did not select the checkbox.

Is there something i'm missing that i should add to the page?