Hooks for add-ons

Beyond columns, Gridline has hooks for code that changes how products are listed and saved, or adds to the Bulk Editor screen. Gridline Pro is built entirely on them.

Checking a product before it's saved

gridline_check runs once a product's changes are applied and before it's saved. Return errors by column key; any error stops that product being saved, and the message appears on the cell.

// Products in "Clearance" can't go above $50.
add_filter( 'gridline_check', function ( $errors, $product, $changed ) {
	if ( in_array( 'regular_price', $changed, true )
		&& has_term( 'clearance', 'product_cat', $product->get_id() )
		&& (float) $product->get_regular_price( 'edit' ) > 50 ) {
		$errors['regular_price'] = 'Clearance products cost $50 or less.';
	}
	return $errors;
}, 10, 3 );

After a save

gridline_save_result filters what a save sends back to the grid. Its second argument lists every cell that changed as [ product ID, column key, old value, new value ], which makes it a good place to log changes:

add_filter( 'gridline_save_result', function ( $result, $changed ) {
	foreach ( $changed as list( $id, $key, $old, $new ) ) {
		error_log( sprintf( 'Bulk Editor: product %d %s %s → %s', $id, $key, wp_json_encode( $old ), wp_json_encode( $new ) ) );
	}
	return $result;
}, 10, 2 );

Extra rows and request parameters

• gridline_list_args gets the arguments for a page of products and the REST request, so you can read your own (sanitized) query parameters.
• gridline_product_rows returns rows to show under a product, built with Extendiment\Gridline\Editor::row(). Pages still count products only.

Gridline Pro uses the pair for its "Show variations" option.

The Bulk Editor screen

• gridline_editor_load fires when the screen loads. Enqueue your script there, with gridline as a dependency:

  add_action( 'gridline_editor_load', function () {
  	add_action( 'admin_enqueue_scripts', function () {
  		wp_enqueue_script( 'my-grid', plugins_url( 'my-grid.js', __FILE__ ), array( 'gridline', 'wp-hooks' ), '1.0', true );
  	} );
  } );
  

• gridline_page_actions prints next to the screen's title; use page-title-action buttons there.

• gridline_loaded fires once Gridline has loaded (only when WooCommerce is active). Hook an add-on's setup to it; GRIDLINE_VERSION is defined from then on.

The grid's JavaScript

The grid sets window.gridline and starts once the page is ready, after every script in the footer has run, so your script can add its wp.hooks first. Give your hooks your own namespace.

Hook	Gets	Use it to
gridline.init (action)	the API	run once before the first load
gridline.query (filter)	query parameters, state	add parameters to the products request (read them with gridline_list_args)
gridline.filters (filter)	elements, state	add controls after the Filter button
gridline.bulkActions (filter)	elements, state	add buttons to the left of the filters
gridline.selectable (filter)	false	return true to show a checkbox column; selected row IDs are in state.selected
gridline.rowClass (filter)	class names, row	add classes to a row
gridline.savedNotice (filter)	HTML parts, result	add to the notice after a save (escape text with gridline.escape())
gridline.loaded (action)	state	react after a page of products loads

// A button that shows how many products are on the page.
wp.hooks.addFilter( 'gridline.bulkActions', 'my-grid', ( nodes, state ) => nodes.concat(
	window.gridline.el( 'button', {
		type: 'button',
		class: 'button',
		text: 'Count',
		onclick: () => window.gridline.notice( 'info', window.gridline.escape( state.rows.length + ' products on this page' ) ),
	} )
) );

window.gridline also has api( path, options ) for Gridline's REST routes, setValue( row, key, value ) to make an unsaved change, rowById(), render(), load(), go( changes ) (change filters or page and reload, after asking about unsaved changes), pickImages() for the media library, and more; the plugin's README lists them all.

REST API

gridline/v1/products lists (GET, with the grid's parameters) and saves (POST, changes as [ { id, key, value } ]) for users who can edit products. Gridline Pro adds its routes to the same namespace.