Filters and hooks

Stockline's hooks are WordPress filters and actions. Put the examples in a small custom plugin or your child theme's functions.php.

The markup

The stock line is a paragraph that keeps WooCommerce's classes and adds Stockline's own:

<p class="stock out-of-stock stockline stockline--out-of-stock stockline--badge stockline--colored stockline--color-cf222e">
  <span class="stockline__icon" aria-hidden="true"><svg>…</svg></span>
  <span class="stockline__text">Sold out, back soon</span>
</p>

• stockline--{state}: in-stock, low-stock, backorder, out-of-stock, or an added state's key.
• stockline--plain or stockline--badge: the style.
• stockline--colored and stockline--color-{hex}: only when the state has a colour. The colour class sets the CSS variable --stockline-color.

So you can restyle it with CSS alone, for example a squarer badge:

.stockline--badge { border-radius: 4px; }

stockline_stock_html

Filters the final markup. Gets the HTML, the product (or variation) and the state.

// Add a "Notify me" link under out of stock messages.
add_filter( 'stockline_stock_html', function ( $html, $product, $state ) {
	if ( 'out_of_stock' === $state ) {
		$html .= '<p class="notify-me"><a href="/notify?product=' . $product->get_id() . '">Email me when it is back</a></p>';
	}
	return $html;
}, 10, 3 );

The states are in_stock, low_stock, backorder and out_of_stock (with underscores here), plus any added with stockline_states.

stockline_placeholders

Adds placeholders for messages. Gets the placeholder => value pairs and the product. Values are inserted as HTML, so escape anything that comes from user input.

// {sku} in any stock message.
add_filter( 'stockline_placeholders', function ( $pairs, $product ) {
	$pairs['{sku}'] = esc_html( $product->get_sku() );
	return $pairs;
}, 10, 2 );

stockline_enqueue_styles

Stockline's stylesheet loads on single product pages only. Return true where products are shown some other way, so the icons, colours and badges are styled there too.

// A landing page with a Single Product block.
add_filter( 'stockline_enqueue_styles', function ( $enqueue ) {
	return $enqueue || is_page( 'spring-collection' );
} );

stockline_state

Changes the state a product is shown in. Only Stockline's four states or one added with stockline_states are accepted; anything else is ignored. See Adding your own stock state for a full example.

stockline_product_settings

Replaces the store's settings for one product or variation. Gets an array with message, icon and color, the product, and the state. An empty message keeps WooCommerce's text, none means no icon, and an empty colour keeps the theme's. Stockline checks the result: an unknown icon becomes none and an invalid colour is dropped.

// A different backorder message for one category.
add_filter( 'stockline_product_settings', function ( $settings, $product, $state ) {
	$id = $product->get_parent_id() ?: $product->get_id();
	if ( 'backorder' === $state && has_term( 'furniture', 'product_cat', $id ) ) {
		$settings['message'] = 'Made to order, ships in 6–8 weeks';
		$settings['icon']    = 'truck';
	}
	return $settings;
}, 10, 3 );

Stockline Pro uses this filter for its per-product and per-variation settings. If you use both, run yours at a later priority (e.g. 20) to override Pro, or an earlier one to let Pro's product settings win.

stockline_page_colors

If your stockline_product_settings code sets a colour that isn't one of the store's, add it here so its CSS rule is in the page head. Gets the list of hex colours and the page's product (null when the page isn't a product page).

add_filter( 'stockline_page_colors', function ( $colors, $product ) {
	$colors[] = '#8250df';
	return $colors;
}, 10, 2 );

Colours that aren't listed still work on most pages: Stockline adds their rule in the footer when it first meets them. Listing them avoids a moment without colour on classic themes, and covers variations loaded after the page.

stockline_loaded

An action that fires once Stockline has loaded (on plugins_loaded, and only when WooCommerce is active). Hook an add-on's setup to it, so it only runs when Stockline is there.

add_action( 'stockline_loaded', function () {
	// Stockline's classes, such as Extendiment\Stockline\States, are available here.
} );

STOCKLINE_VERSION is defined from then on, for version checks.