AddJsCommand.php

<?php

namespace Drupal\Core\Ajax;


/**
 * An AJAX command for adding JS to the page via AJAX.
 *
 * This command will make sure all the files are loaded before continuing
 * executing the next AJAX command. This command is implemented by
 * Drupal.AjaxCommands.prototype.add_js() defined in misc/ajax.js.
 *
 * @see misc/ajax.js
 *
 * @ingroup ajax
 */
class AddJsCommand implements CommandInterface {
    
    /**
     * An array containing attributes of the scripts to be added to the page.
     *
     * @var string[]
     */
    protected $scripts;
    
    /**
     * A CSS selector string.
     *
     * If the command is a response to a request from an #ajax form element then
     * this value will default to 'body'.
     *
     * @var string
     */
    protected $selector;
    
    /**
     * Constructs an AddJsCommand.
     *
     * @param array $scripts
     *   An array containing the attributes of the 'script' tags to be added to
     *   the page. i.e. `['src' => 'someURL', 'defer' => TRUE]` becomes
     *   `<script src="someURL" defer>`.
     * @param string $selector
     *   A CSS selector of the element where the script tags will be appended.
     */
    public function __construct(array $scripts, string $selector = 'body') {
        $this->scripts = $scripts;
        $this->selector = $selector;
    }
    
    /**
     * {@inheritdoc}
     */
    public function render() {
        return [
            'command' => 'add_js',
            'selector' => $this->selector,
            'data' => $this->scripts,
        ];
    }

}