Add third party translation (WIP)

Module.php

@@ -286,6 +286,14 @@ class Module extends \yii\base\Module
      */
     public $scanners = [];
 
+    /**
+     * @var array Configuration for a third-party translator (e.g.: Google, Yandex, etc.) that can be used for
+     * text translation.
+     *
+     * The translator should implement the `lajax\translatemanager\translation\Translator` interface.
+     */
+    public $translator;
+
     /**
      * @inheritdoc
      */

assets/javascripts/translate.js

@@ -42,11 +42,27 @@ var translate = (function () {
         _translateLanguage($this);
     }
 
+    /**
+     * @param {$} $btn
+     */
+    function _translateText($btn) {
+        var $translation = $btn.closest('tr').find('.translation');
+        console.log($translation);
+
+        helpers.post('/translatemanager/language/translate-text', {
+            id: $translation.data('id'),
+            language_id: $('#language_id').val()
+        });
+    }
+
     return {
         init: function () {
             $('#translates').on('click', '.source', function () {
                 _copySourceToTranslation($(this));
             });
+            $('#translates').on('click', '.js-translate-text', function () {
+                _translateText($(this));
+            });
             $('#translates').on('click', 'button', function () {
                 _translateLanguage($(this));
             });

controllers/LanguageController.php

@@ -35,11 +35,11 @@ public function behaviors()
         return [
             'access' => [
                 'class' => AccessControl::className(),
-                'only' => ['list', 'change-status', 'optimizer', 'scan', 'translate', 'save', 'dialog', 'message', 'view', 'create', 'update', 'delete', 'delete-source', 'import', 'export'],
+                'only' => ['list', 'change-status', 'optimizer', 'scan', 'translate', 'translate-text', 'save', 'dialog', 'message', 'view', 'create', 'update', 'delete', 'delete-source', 'import', 'export'],
                 'rules' => [
                     [
                         'allow' => true,
-                        'actions' => ['list', 'change-status', 'optimizer', 'scan', 'translate', 'save', 'dialog', 'message', 'view', 'create', 'update', 'delete', 'delete-source', 'import', 'export'],
+                        'actions' => ['list', 'change-status', 'optimizer', 'scan', 'translate', 'translate-text', 'save', 'dialog', 'message', 'view', 'create', 'update', 'delete', 'delete-source', 'import', 'export'],
                         'roles' => $this->module->roles,
                     ],
                 ],
@@ -71,6 +71,9 @@ public function actions()
             'translate' => [
                 'class' => 'lajax\translatemanager\controllers\actions\TranslateAction',
             ],
+            'translate-text' => [
+                'class' => 'lajax\translatemanager\controllers\actions\TranslateTextAction',
+            ],
             'save' => [
                 'class' => 'lajax\translatemanager\controllers\actions\SaveAction',
             ],

controllers/actions/TranslateAction.php

@@ -42,6 +42,7 @@ public function run()
             'dataProvider' => $dataProvider,
             'searchModel' => $searchModel,
             'searchEmptyCommand' => $this->controller->module->searchEmptyCommand,
+            'isTranslationApiAvailable' => !empty($this->controller->module->translator),
             'language_id' => Yii::$app->request->get('language_id', ''),
         ]);
     }

controllers/actions/TranslateTextAction.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace lajax\translatemanager\controllers\actions;
+
+use Yii;
+use yii\web\Response;
+use yii\base\Exception as BaseException;
+use lajax\translatemanager\services\Generator;
+use lajax\translatemanager\models\LanguageTranslate;
+use lajax\translatemanager\models\LanguageSource;
+use lajax\translatemanager\translation\Translator;
+use lajax\translatemanager\translation\Exception as TranslationException;
+
+/**
+ * Text translation with third party service.
+ *
+ * @author moltam
+ */
+class TranslateTextAction extends \yii\base\Action
+{
+    /**
+     * @return array
+     */
+    public function run()
+    {
+        Yii::$app->response->format = Response::FORMAT_JSON;
+
+        $id = Yii::$app->request->post('id', 0);
+        $languageId = Yii::$app->request->post('language_id', Yii::$app->language);
+
+        $languageTranslate = LanguageTranslate::findOne(['id' => $id, 'language' => $languageId]) ?:
+            new LanguageTranslate(['id' => $id, 'language' => $languageId]);
+
+        try {
+            $languageTranslate->translation = $this->translateText($id, $languageId);
+        } catch (BaseException $e) {
+            Yii::error('Translation failed! ' . $e->getMessage(), 'translatemanager');
+            $languageTranslate->addError('translation', 'API translation failed!');
+        }
+
+        if ($languageTranslate->validate(null, false) && $languageTranslate->save()) {
+            $generator = new Generator($this->controller->module, $languageId);
+            $generator->run();
+        }
+
+        return $languageTranslate->getErrors();
+    }
+
+    /**
+     * @param int $sourceId
+     * @param string $languageId
+     *
+     * @return string
+     *
+     * @throws BaseException
+     */
+    protected function translateText($sourceId, $languageId)
+    {
+        if (!$this->controller->module->translator) {
+            throw new BaseException('No translator configured!');
+        }
+
+        $source = LanguageSource::findOne($sourceId);
+        if (!$source) {
+            throw new BaseException('Invalid language source id!');
+        }
+
+        /* @var $translator Translator */
+        $translator = Yii::createObject($this->controller->module->translator);
+
+        try {
+            return $translator->translate($source->message, $languageId);
+        } catch (TranslationException $e) {
+            throw new BaseException('Translation failed: ' . $e->getMessage(), 1, $e);
+        }
+    }
+}

translation/BaseTranslator.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace lajax\translatemanager\translation;
+
+use Yii;
+use lajax\translatemanager\translation\client\TranslatorApiClient;
+
+/**
+ * Base class for translators.
+ *
+ * @author moltam
+ */
+abstract class BaseTranslator extends \yii\base\Object implements Translator
+{
+    /**
+     * @var array|TranslatorApiClient The client used for communication.
+     */
+    public $apiClient = [
+        'class' => 'lajax\translatemanager\translation\client\CurlApiClient',
+    ];
+
+    public function init()
+    {
+        parent::init();
+
+        $this->apiClient = Yii::createObject($this->apiClient);
+    }
+}

translation/Exception.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace lajax\translatemanager\translation;
+
+/**
+ * Base exception for translation related errors.
+ *
+ * @author moltam
+ */
+class Exception extends \yii\base\Exception
+{
+}

translation/GoogleTranslator.php

@@ -0,0 +1,111 @@
+<?php
+
+namespace lajax\translatemanager\translation;
+
+use Yii;
+use yii\helpers\Json;
+
+/**
+ * Translator using the Google Cloud Translation API.
+ *
+ * More information on this service: https://cloud.google.com/translate/
+ *
+ * Required configuration:
+ *
+ * ```php
+ * [
+ *     'class' => 'lajax\translatemanager\translation\GoogleTranslator',
+ *     'apiKey' => 'YOUR_API_KEY',
+ * ]
+ * ```
+ *
+ * @author moltam
+ */
+class GoogleTranslator extends BaseTranslator
+{
+    /**
+     * @var string The API key for authentication.
+     */
+    public $apiKey;
+
+    /**
+     * @var string
+     */
+    private static $baseApiUrl = 'https://translation.googleapis.com';
+
+    /**
+     * @inheritdoc
+     */
+    public function translate($text, $target, $source = null, $format = 'html')
+    {
+        $response = $this->apiClient->send($this->buildApiUrl('/language/translate/v2'), 'POST', [
+            'key' => $this->apiKey,
+            'q' => $text,
+            'target' => substr($target, 0, 2),
+            'source' => substr($source, 0, 2),
+            'format' => $format,
+        ]);
+
+        $decodesResponse = $this->decodeResponse($response);
+        $this->checkResponse($decodesResponse);
+
+        return $decodesResponse['data']['translations'][0]['translatedText'];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function detect($text)
+    {
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getLanguages()
+    {
+    }
+
+    /**
+     * @param string $uri
+     * @param array $queryParams [optional]
+     *
+     * @return string
+     */
+    private function buildApiUrl($uri, array $queryParams = [])
+    {
+        return self::$baseApiUrl . $uri . '?' . http_build_query($queryParams);
+    }
+
+    /**
+     * @param string $response
+     *
+     * @return array
+     *
+     * @throws Exception
+     */
+    private function decodeResponse($response)
+    {
+        $decodesResponse = Json::decode($response);
+        if (!$decodesResponse) {
+            throw new Exception('Invalid API response: json decode failed!');
+        }
+
+        return $decodesResponse;
+    }
+
+    /**
+     * @param array $response
+     *
+     * @throws Exception
+     */
+    private function checkResponse($response)
+    {
+        if (isset($response['error'])) {
+            $error = $response['error'];
+            Yii::error('API response: ' . var_export($response, true), 'translatemanager');
+
+            throw new Exception("API error: $error[message]", $error['code']);
+        }
+    }
+}

translation/Translator.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace lajax\translatemanager\translation;
+
+/**
+ * A translator that can translate arbitrary text.
+ *
+ * @author moltam
+ */
+interface Translator
+{
+    /**
+     * Translates the given text to the specified language.
+     *
+     * @param string $text The text to translate.
+     * @param string $target The language code for translation.
+     * @param string $source [optional]
+     * <p>The language code of the source text. If not given, the translator tries to detect the language.</p>
+     * @param string $format [optional]
+     * <p>The format of the source text. Possible values:
+     * - html: string with HTML markup,
+     * - text: plain text without markup.
+     * </p>
+     *
+     * @return string The translation.
+     *
+     * @throws Exception If the text cannot be translated, or an error occurred during translation.
+     */
+    public function translate($text, $target, $source = null, $format = 'html');
+
+    /**
+     * Detects the language of the specified text.
+     *
+     * @param string $text The analyzed text.
+     *
+     * @return string The language code for translation.
+     *
+     * @throws Exception If the language cannot be detected, or an error occurred during detection.
+     */
+    public function detect($text);
+
+    /**
+     * Returns the languages supported by the translator.
+     *
+     * @return string[] A list of language codes.
+     */
+    public function getLanguages();
+}

translation/client/ClientException.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace lajax\translatemanager\translation\client;
+
+use lajax\translatemanager\translation\Exception;
+
+/**
+ * Exception for API communication errors.
+ *
+ * @author moltam
+ */
+class ClientException extends Exception
+{
+}