gform_field_deleted

<script type="text/javascript">
	( function () {
		if ( window.myFieldDeletedBound ) return; // avoid double-binding
		window.myFieldDeletedBound = true;

		const previous = document.ongform_field_deleted;

		document.ongform_field_deleted = function ( event, form, fieldId ) {
			if ( form && form.id == 44 && fieldId == 1 ) {
				// do something specific to this form and field
				alert( 'You deleted field ' + fieldId );
			}
			// keep any handler that was already assigned
			if ( typeof previous === 'function' ) {
				return previous.apply( this, arguments );
			}
		};
	} )();
</script>

add_action( 'gform_admin_pre_render', 'pre_render_function' );
function pre_render_function( $form ) {
	?>
	<script type="text/javascript">
		( function () {
			if ( window.myFieldDeletedBound ) return; // avoid double-binding
			window.myFieldDeletedBound = true;

			const previous = document.ongform_field_deleted;

			document.ongform_field_deleted = function ( event, form, fieldId ) {
				if ( form && form.id == 43 && fieldId == 1 ) {
					// do something specific to this form and field
					alert( 'You deleted field ' + fieldId );
				}
				// keep any handler that was already assigned
				if ( typeof previous === 'function' ) {
					return previous.apply( this, arguments );
				}
			};
		} )();
	</script>
	<?php
	return $form;
}