aristath/kirki

<?php
/**
 * Automatic postMessage scripts calculation for Kirki controls.
 *
 * @package kirki-framework/module-postmessage
 * @author Ari Stathopoulos (@aristath)
 * @copyright Copyright (c) 2019, Ari Stathopoulos (@aristath)
 * @license https://opensource.org/licenses/MIT
 * @since 1.0.0
 */

namespace Kirki\Module;

use Kirki\URL;

/**
 * Adds styles to the customizer.
 */
class Postmessage {

    /**
     * An array of fields to be processed.
     *
     * @access protected
     * @since 1.0.0
     * @var array
     */
    protected $fields = [];

    /**
     * Constructor.
     *
     * @access public
     * @since 1.0.0
     */
    public function __construct() {
        add_action( 'customize_preview_init', [ $this, 'postmessage' ] );
        add_action( 'kirki_field_add_setting_args', [ $this, 'field_add_setting_args' ] );
    }

    /**
     * Filter setting args before adding the setting to the customizer.
     *
     * @access public
     * @since 1.0.0
     * @param array $args The field arguments.
     * @return array
     */
    public function field_add_setting_args( $args ) {

        if ( ! isset( $args['transport'] ) ) {
            return $args;
        }

        $args['transport'] = 'auto' === $args['transport'] ? 'postMessage' : $args['transport'];

        if ( 'postMessage' === $args['transport'] ) {
            $args['js_vars'] = isset( $args['js_vars'] ) ? (array) $args['js_vars'] : [];
            $args['output']  = isset( $args['output'] ) ? (array) $args['output'] : [];
            $js_vars         = $args['js_vars'];

            // Try to auto-generate js_vars.
            // First we need to check if js_vars are empty, and that output is not empty.
            if ( empty( $args['js_vars'] ) && ! empty( $args['output'] ) ) {

                foreach ( $args['output'] as $output ) {
                    $output['element']  = isset( $output['element'] ) ? $output['element'] : ':root';
                    $output['element']  = is_array( $output['element'] ) ? implode( ',', $output['element'] ) : $output['element'];
                    $output['function'] = isset( $output['function'] ) ? $output['function'] : 'style';
                    $js_vars[]          = $output;
                }
            }

            $args['js_vars'] = $js_vars;
        }

        $this->fields[] = $args;

        return $args;

    }

    /**
     * Enqueues the postMessage script
     * and adds variables to it using the wp_localize_script function.
     * The rest is handled via JS.
     */
    public function postmessage() {

        wp_enqueue_script( 'kirki_auto_postmessage', URL::get_from_path( __DIR__ . '/postMessage.js' ), [ 'jquery', 'customize-preview', 'wp-hooks' ], '4.0', true );

        $fields = $this->fields;

        // Compatibility with v3 API.
        if ( class_exists( '\Kirki\Compatibility\Kirki' ) ) {
            $fields = array_merge( \Kirki\Compatibility\Kirki::$fields, $fields );
        }

        $data = [];

        foreach ( $fields as $field ) {
            if ( isset( $field['transport'] ) && 'postMessage' === $field['transport'] && isset( $field['js_vars'] ) && ! empty( $field['js_vars'] ) && is_array( $field['js_vars'] ) && isset( $field['settings'] ) ) {
                $data[] = $field;
            }
        }

        wp_localize_script( 'kirki_auto_postmessage', 'kirkiPostMessageFields', $data );

        $extras = apply_filters( 'kirki_postmessage_script', false );

        if ( $extras ) {
            wp_add_inline_script( 'kirki_auto_postmessage', $extras, 'after' );
        }

    }

}