Issue #60 Cleanup creation logic and allow empty default language

Author: mikehaertl

README.md

@@ -240,6 +240,18 @@ for the default language in the URL. For example if default language is `fr`:
 
 In this case, `fr` will first be stored as last used language before the user is redirected.
 
+If you explicitely need to create a URL to the default language without any language code,
+you can also pass an empty string as language:
+
+```php
+<?= Url::to(['demo/action', 'language' => '']) ?>
+```
+
+This will give you:
+
+    /demo/action
+
+
 ### Language Detection
 
 If a user visits your site for the first time and there's no language stored in session

UrlManager.php

@@ -194,31 +194,29 @@ public function createUrl($params)
         if ($this->enableLocaleUrls && $this->languages) {
             $params = (array) $params;
 
-            if (isset($params[$this->languageParam])) {
-                $language = $params[$this->languageParam];
+            $addLanguage = false;
+            $isLanguageGiven = isset($params[$this->languageParam]);
+            $language = $isLanguageGiven ? $params[$this->languageParam] : Yii::$app->language;
+            $isDefaultLanguage = $language===$this->getDefaultLanguage();
+
+            if ($isLanguageGiven) {
                 unset($params[$this->languageParam]);
-                $languageRequired = true;
-            } else {
-                $language = Yii::$app->language;
-                $languageRequired = false;
             }
 
-            // Do not use prefix for default language to prevent unnecessary redirect if there's no persistence and no detection
+            $url = parent::createUrl($params);
+
             if (
-                $languageRequired && $language===$this->getDefaultLanguage() &&
-                !$this->enableDefaultLanguageUrlCode && !$this->enableLanguagePersistence && !$this->enableLanguageDetection
-            ) {
-                $languageRequired = false;
-            }
+                // Only add language if it's not empty and ...
+                $language!=='' && (
 
-            $url = parent::createUrl($params);
+                    // ... it's not the default language or default language uses URL code ...
+                    !$isDefaultLanguage || $this->enableDefaultLanguageUrlCode ||
 
-            // Unless a language was explicitely specified in the parameters we can return a URL without any prefix
-            // for the default language, if suffixes are disabled for the default language. In any other case we
-            // always add the suffix, e.g. to create "reset" URLs that explicitely contain the default language.
-            if (!$languageRequired && !$this->enableDefaultLanguageUrlCode && $language===$this->getDefaultLanguage()) {
-                return  $url;
-            } else {
+                    // ... or if a language is explicitely given, but only if either persistence or detection is enabled.
+                    // This way a "reset URL" can be created for the default language.
+                    $isLanguageGiven && ($this->enableLanguagePersistence || $this->enableLanguageDetection)
+                )
+            ) {
                 $key = array_search($language, $this->languages);
                 if (is_string($key)) {
                     $language = $key;
@@ -250,6 +248,8 @@ public function createUrl($params)
                 }
                 $needleLength = strlen($needle);
                 return $needleLength ? substr_replace($url, "$needle/$language", 0, $needleLength) : "/$language$url";
+            } else {
+                return $url;
             }
         } else {
             return parent::createUrl($params);

tests/UrlCreationTest.php

@@ -115,6 +115,7 @@ public function testCreateHomeUrlWithLanguageFromUrl()
             ],
         ]);
         $this->mockRequest('/de/site/page');
+        $this->assertEquals($this->prepareUrl('/'), Url::to(['/site/index', 'language' => '']));
         $this->assertEquals($this->prepareUrl('/de'), Url::to(['/site/index']));
         $this->assertEquals($this->prepareUrl('/de?x=y'), Url::to(['/site/index', 'x' => 'y']));
     }
@@ -129,6 +130,7 @@ public function testCreateAbsoluteHomeUrlWithLanguageFromUrl()
             ],
         ]);
         $this->mockRequest('/de/site/page');
+        $this->assertEquals('http://localhost'.$this->prepareUrl('/'), Url::to(['/site/index', 'language' => ''], 'http'));
         $this->assertEquals('http://localhost'.$this->prepareUrl('/de'), Url::to(['/site/index'], 'http'));
         $this->assertEquals('http://localhost'.$this->prepareUrl('/de?x=y'), Url::to(['/site/index', 'x' => 'y'], 'http'));
     }
@@ -154,6 +156,10 @@ public function testCreateUrlWithSpecificLanguage()
             ],
         ]);
         $this->mockRequest('/de/site/page');
+        $this->assertEquals($this->prepareUrl('/'), Url::to(['/', 'language' => '']));
+        $this->assertEquals($this->prepareUrl('/demo/action'), Url::to(['/demo/action', 'language' => '']));
+        $this->assertEquals($this->prepareUrl('/en'), Url::to(['/', 'language' => 'en']));
+        $this->assertEquals($this->prepareUrl('/en/demo/action'), Url::to(['/demo/action', 'language' => 'en']));
         $this->assertEquals($this->prepareUrl('/en-us'), Url::to(['/', 'language' => 'en-US']));
         $this->assertEquals($this->prepareUrl('/en-us/demo/action'), Url::to(['/demo/action', 'language' => 'en-US']));
         $this->assertEquals($this->prepareUrl('/en-us/demo/action?x=y'), Url::to(['/demo/action', 'language' => 'en-US', 'x'=>'y']));
@@ -388,10 +394,12 @@ public function testCreateUrlWithoutDefaultLanguageIfPersistenceAndDetectionDisa
             'enableLanguagePersistence' => false,
             'enableLanguageDetection' => false,
             'rules' => [
+                '' => 'site/index',
                 '/foo/<term:.+>/bar' => 'slug/action',
             ],
         ]);
         $this->mockRequest('/de/site/page');
+        $this->assertEquals($this->prepareUrl('/'), Url::to(['/site/index', 'language' => 'en']));
         $this->assertEquals($this->prepareUrl('/demo/action'), Url::to(['/demo/action', 'language' => 'en']));
         $this->assertEquals($this->prepareUrl('/demo/action?x=y'), Url::to(['/demo/action', 'x' => 'y', 'language' => 'en']));
         $this->assertEquals($this->prepareUrl('/foo/baz/bar'), Url::to(['/slug/action', 'term' => 'baz', 'language' => 'en']));