wp_get_block_css_selector

WordPress Version: 6.3

/**
 * Determines the CSS selector for the block type and property provided,
 * returning it if available.
 *
 * @since 6.3.0
 *
 * @param WP_Block_Type $block_type The block's type.
 * @param string|array  $target     The desired selector's target, `root` or array path.
 * @param boolean       $fallback   Whether to fall back to broader selector.
 *
 * @return string|null CSS selector or `null` if no selector available.
 */
function wp_get_block_css_selector($block_type, $target = 'root', $fallback = false)
{
    if (empty($target)) {
        return null;
    }
    $has_selectors = !empty($block_type->selectors);
    // Root Selector.
    // Calculated before returning as it can be used as fallback for
    // feature selectors later on.
    $root_selector = null;
    if ($has_selectors && isset($block_type->selectors['root'])) {
        // Use the selectors API if available.
        $root_selector = $block_type->selectors['root'];
    } elseif (isset($block_type->supports['__experimentalSelector']) && is_string($block_type->supports['__experimentalSelector'])) {
        // Use the old experimental selector supports property if set.
        $root_selector = $block_type->supports['__experimentalSelector'];
    } else {
        // If no root selector found, generate default block class selector.
        $block_name = str_replace('/', '-', str_replace('core/', '', $block_type->name));
        $root_selector = ".wp-block-{$block_name}";
    }
    // Return selector if it's the root target we are looking for.
    if ('root' === $target) {
        return $root_selector;
    }
    // If target is not `root` we have a feature or subfeature as the target.
    // If the target is a string convert to an array.
    if (is_string($target)) {
        $target = explode('.', $target);
    }
    // Feature Selectors ( May fallback to root selector ).
    if (1 === count($target)) {
        $fallback_selector = $fallback ? $root_selector : null;
        // Prefer the selectors API if available.
        if ($has_selectors) {
            // Look for selector under `feature.root`.
            $path = array_merge($target, array('root'));
            $feature_selector = _wp_array_get($block_type->selectors, $path, null);
            if ($feature_selector) {
                return $feature_selector;
            }
            // Check if feature selector is set via shorthand.
            $feature_selector = _wp_array_get($block_type->selectors, $target, null);
            return is_string($feature_selector) ? $feature_selector : $fallback_selector;
        }
        // Try getting old experimental supports selector value.
        $path = array_merge($target, array('__experimentalSelector'));
        $feature_selector = _wp_array_get($block_type->supports, $path, null);
        // Nothing to work with, provide fallback or null.
        if (null === $feature_selector) {
            return $fallback_selector;
        }
        // Scope the feature selector by the block's root selector.
        return WP_Theme_JSON::scope_selector($root_selector, $feature_selector);
    }
    // Subfeature selector
    // This may fallback either to parent feature or root selector.
    $subfeature_selector = null;
    // Use selectors API if available.
    if ($has_selectors) {
        $subfeature_selector = _wp_array_get($block_type->selectors, $target, null);
    }
    // Only return if we have a subfeature selector.
    if ($subfeature_selector) {
        return $subfeature_selector;
    }
    // To this point we don't have a subfeature selector. If a fallback
    // has been requested, remove subfeature from target path and return
    // results of a call for the parent feature's selector.
    if ($fallback) {
        return wp_get_block_css_selector($block_type, $target[0], $fallback);
    }
    return null;
}