LangSelector.php

<?php
/**
 * Created by PhpStorm.
 * User: artem_000
 * Date: 9/3/2015
 * Time: 12:43 PM
 */

namespace integready\localeurls;

use Yii;
use yii\bootstrap\Dropdown;

/**
 * Class LangSelector
 * @package integready\localeurls
 */
class LangSelector extends Dropdown
{

    private static $_labels;

    private static $_currentLanguageLabel;

    private $_isError;

    public function init()
    {
        $route          = Yii::$app->controller->route;
        $appLanguage    = Yii::$app->language;
        $params         = $_GET;
        $this->_isError = $route === Yii::$app->errorHandler->errorAction;

        array_unshift($params, '/' . $route);

        foreach (Yii::$app->urlManager->languages as $language) {
            $isWildcard = substr($language, -2) === '-*';
            if ($language === $appLanguage ||
                // Also check for wildcard language
                $isWildcard && substr($appLanguage, 0, 2) === substr($language, 0, 2)
            ) {
                self::$_currentLanguageLabel = $language;
                continue;   // Exclude the current language
            }
            if ($isWildcard) {
                $language = substr($language, 0, 2);
            }
            $params['language'] = $language;
            $this->items[]      = [
                'label'   => self::label($language),
                'url'     => $params,
                'options' => ['class' => [
                    $language,
                ]],
            ];
        }
        parent::init();
    }

    /**
     * @param string $code
     *
     * @return string|null
     */
    public static function label($code)
    {
        if (self::$_labels === null) {
            self::$_labels = [
                'ru-RU' => Yii::t(Yii::$app->urlManager->translateCategory, 'lang-russian'),
                'en-US' => Yii::t(Yii::$app->urlManager->translateCategory, 'lang-english'),
                'fr-FR' => Yii::t(Yii::$app->urlManager->translateCategory, 'lang-france'),
                'zh-CN' => Yii::t(Yii::$app->urlManager->translateCategory, 'lang-chinese'),
            ];
        }

        return isset(self::$_labels[$code]) ? self::$_labels[$code] : null;
    }

    /**
     * @inheritdoc
     */
    public function run()
    {
        // Only show this widget if we're not on the error page
        if ($this->_isError || count(Yii::$app->urlManager->languages) < 2) {
            return '';
        } else {
            $html = '<li class="dropdown ' . self::$_currentLanguageLabel . '"><a href="#" data-toggle="dropdown" class="dropdown-toggle">' . PHP_EOL .
                self::label(self::$_currentLanguageLabel) . '<b class="caret"></b></a>' . PHP_EOL;
            $html .= parent::run();
            $html .= '</li>';

            return $html;
        }
    }
}