add LocalizationHandler

and remove the evil LocalizedEndpointProxy

src/GW2Api.php

@@ -38,6 +38,7 @@ function __construct( array $options = [] ) {
         $this->options = $options;
 
         $this->registerHandler( '\GW2Treasures\GW2Api\V2\Authentication\AuthenticationHandler' );
+        $this->registerHandler( '\GW2Treasures\GW2Api\V2\Localization\LocalizationHandler' );
     }
 
     protected function getOptions( array $options = [] ) {

src/V2/EndpointTrait.php

@@ -31,4 +31,6 @@ protected abstract function request( array $query = [], $url = null, $method = '
      * @return ApiResponse[]
      */
     public abstract function requestMany( array $queries = [], $url = null, $method = 'GET', $options = [] );
+
+    public abstract function attach( ApiHandler $handler );
 }

src/V2/Localization/ILocalizedEndpoint.php

@@ -2,10 +2,21 @@
 
 namespace GW2Treasures\GW2Api\V2\Localization;
 
-interface ILocalizedEndpoint {
+use GW2Treasures\GW2Api\V2\IEndpoint;
+
+interface ILocalizedEndpoint extends IEndpoint {
     /**
+     * Change the language of this endpoint.
+     *
      * @param string $language
      * @return $this
      */
-    function lang( $language );
+    public function lang( $language );
+
+    /**
+     * Get the current language
+     *
+     * @return string
+     */
+    public function getLang();
 }

src/V2/Localization/LocalizationHandler.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace GW2Treasures\GW2Api\V2\Localization;
+
+use GuzzleHttp\Message\RequestInterface;
+use GW2Treasures\GW2Api\V2\ApiHandler;
+
+class LocalizationHandler extends ApiHandler {
+    function __construct( ILocalizedEndpoint $endpoint ) {
+        $this->endpoint = $endpoint;
+    }
+
+    /**
+     * @return ILocalizedEndpoint
+     */
+    protected function getEndpoint() {
+        return parent::getEndpoint();
+    }
+
+    /**
+     * @param RequestInterface $request
+     */
+    public function onRequest( RequestInterface $request ) {
+        $request->getQuery()->add( 'lang', $this->getEndpoint()->getLang() );
+    }
+}

src/V2/Localization/LocalizedEndpoint.php

@@ -11,13 +11,22 @@ trait LocalizedEndpoint {
     protected $language = 'en';
 
     /**
-     * Get a localized version of this endpoint.
+     * Change the language of this endpoint.
      *
      * @param string $lang
      * @return $this
      */
     public function lang( $lang ) {
-        /** @noinspection PhpParamsInspection */
-        return new LocalizedEndpointProxy( $this, $lang );
+        $this->language = $lang;
+        return $this;
+    }
+
+    /**
+     * Get the current language
+     *
+     * @return string
+     */
+    public function getLang() {
+        return $this->language;
     }
 }

tests/LocalizedEndpointTest.php

@@ -46,28 +46,4 @@ public function testNested() {
         $this->assertEquals( 'fr', $request->getQuery()->get('lang'),
             'LocalizedEndpoint sets correct query parameter value on nested request' );
     }
-
-    public function testPersistence() {
-        $this->mockResponse('[]');
-        $this->mockResponse('[]');
-
-        $en = $this->getLocalizedEndpoint()->lang('en');
-        $de = $this->getLocalizedEndpoint()->lang('de');
-
-        // send first request
-        $en->get();
-        $request = $this->getLastRequest();
-        $this->assertTrue( $request->getQuery()->hasKey('lang'),
-            'LocalizedEndpoint sets ?lang query parameter on first request after creating multiple localized endpoints' );
-        $this->assertEquals( 'en', $request->getQuery()->get('lang'),
-            'LocalizedEndpoint sets correct query parameter value on first request after creating multiple localized endpoints' );
-
-        // send second request
-        $de->get();
-        $request = $this->getLastRequest();
-        $this->assertTrue( $request->getQuery()->hasKey('lang'),
-            'LocalizedEndpoint sets ?lang query parameter on last request after creating multiple localized endpoints and sending the first' );
-        $this->assertEquals( 'de', $request->getQuery()->get('lang'),
-            'LocalizedEndpoint sets correct query parameter value on last request after creating multiple localized endpoints and sending the first' );
-    }
 }