feature #27957 [Routing] Add fallback to cultureless locale for internationalized routes (fancyweb)

This PR was merged into the 4.2-dev branch.

Discussion
----------

[Routing] Add fallback to cultureless locale for internationalized routes

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | https://github.com/symfony/symfony/issues/27938
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/10108

Please check the related issue for the context.

TODO :
- [x] Update CHANGELOG
- [x] Update documentation

Commits
-------

fd2e3c36fb [Routing] Add fallback to cultureless locale for internationalized routes

src/Symfony/Component/Routing/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.2.0
+-----
+
+ * added fallback to cultureless locale for internationalized routes
+
 4.0.0
 -----
 

src/Symfony/Component/Routing/Generator/Dumper/PhpGeneratorDumper.php

@@ -113,10 +113,17 @@ EOF;
             ?? $this->context->getParameter('_locale')
             ?: $this->defaultLocale;
 
-        if (null !== $locale && (self::$declaredRoutes[$name.'.'.$locale][1]['_canonical_route'] ?? null) === $name) {
-            unset($parameters['_locale']);
-            $name .= '.'.$locale;
-        } elseif (!isset(self::$declaredRoutes[$name])) {
+        if (null !== $locale) {
+            do {
+                if ((self::$declaredRoutes[$name.'.'.$locale][1]['_canonical_route'] ?? null) === $name) {
+                    unset($parameters['_locale']);
+                    $name .= '.'.$locale;
+                    break;
+                }
+            } while (false !== $locale = strstr($locale, '_', true));
+        }
+
+        if (!isset(self::$declaredRoutes[$name])) {
             throw new RouteNotFoundException(sprintf('Unable to generate a URL for the named route "%s" as such route does not exist.', $name));
         }
 

src/Symfony/Component/Routing/Generator/UrlGenerator.php

@@ -112,13 +112,21 @@ class UrlGenerator implements UrlGeneratorInterface, ConfigurableRequirementsInt
      */
     public function generate($name, $parameters = array(), $referenceType = self::ABSOLUTE_PATH)
     {
+        $route = null;
         $locale = $parameters['_locale']
             ?? $this->context->getParameter('_locale')
             ?: $this->defaultLocale;
 
-        if (null !== $locale && null !== ($route = $this->routes->get($name.'.'.$locale)) && $route->getDefault('_canonical_route') === $name) {
-            unset($parameters['_locale']);
-        } elseif (null === $route = $this->routes->get($name)) {
+        if (null !== $locale) {
+            do {
+                if (null !== ($route = $this->routes->get($name.'.'.$locale)) && $route->getDefault('_canonical_route') === $name) {
+                    unset($parameters['_locale']);
+                    break;
+                }
+            } while (false !== $locale = strstr($locale, '_', true));
+        }
+
+        if (null === $route = $route ?? $this->routes->get($name)) {
             throw new RouteNotFoundException(sprintf('Unable to generate a URL for the named route "%s" as such route does not exist.', $name));
         }
 

src/Symfony/Component/Routing/Tests/Generator/Dumper/PhpGeneratorDumperTest.php

@@ -84,19 +84,20 @@ class PhpGeneratorDumperTest extends TestCase
         $this->assertEquals('/app.php/testing2', $relativeUrlWithoutParameter);
     }
 
-    public function testDumpWithLocalizedRoutes()
+    public function testDumpWithSimpleLocalizedRoutes()
     {
+        $this->routeCollection->add('test', (new Route('/foo')));
         $this->routeCollection->add('test.en', (new Route('/testing/is/fun'))->setDefault('_locale', 'en')->setDefault('_canonical_route', 'test'));
         $this->routeCollection->add('test.nl', (new Route('/testen/is/leuk'))->setDefault('_locale', 'nl')->setDefault('_canonical_route', 'test'));
 
         $code = $this->generatorDumper->dump(array(
-            'class' => 'LocalizedProjectUrlGenerator',
+            'class' => 'SimpleLocalizedProjectUrlGenerator',
         ));
         file_put_contents($this->testTmpFilepath, $code);
         include $this->testTmpFilepath;
 
         $context = new RequestContext('/app.php');
-        $projectUrlGenerator = new \LocalizedProjectUrlGenerator($context, null, 'en');
+        $projectUrlGenerator = new \SimpleLocalizedProjectUrlGenerator($context, null, 'en');
 
         $urlWithDefaultLocale = $projectUrlGenerator->generate('test');
         $urlWithSpecifiedLocale = $projectUrlGenerator->generate('test', array('_locale' => 'nl'));
@@ -109,6 +110,57 @@ class PhpGeneratorDumperTest extends TestCase
         $this->assertEquals('/app.php/testen/is/leuk', $urlWithSpecifiedLocale);
         $this->assertEquals('/app.php/testing/is/fun', $urlWithEnglishContext);
         $this->assertEquals('/app.php/testen/is/leuk', $urlWithDutchContext);
+
+        // test with full route name
+        $this->assertEquals('/app.php/testing/is/fun', $projectUrlGenerator->generate('test.en'));
+
+        $context->setParameter('_locale', 'de_DE');
+        // test that it fall backs to another route when there is no matching localized route
+        $this->assertEquals('/app.php/foo', $projectUrlGenerator->generate('test'));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Routing\Exception\RouteNotFoundException
+     * @expectedExceptionMessage Unable to generate a URL for the named route "test" as such route does not exist.
+     */
+    public function testDumpWithRouteNotFoundLocalizedRoutes()
+    {
+        $this->routeCollection->add('test.en', (new Route('/testing/is/fun'))->setDefault('_locale', 'en')->setDefault('_canonical_route', 'test'));
+
+        $code = $this->generatorDumper->dump(array(
+        'class' => 'RouteNotFoundLocalizedProjectUrlGenerator',
+      ));
+        file_put_contents($this->testTmpFilepath, $code);
+        include $this->testTmpFilepath;
+
+        $projectUrlGenerator = new \RouteNotFoundLocalizedProjectUrlGenerator(new RequestContext('/app.php'), null, 'pl_PL');
+        $projectUrlGenerator->generate('test');
+    }
+
+    public function testDumpWithFallbackLocaleLocalizedRoutes()
+    {
+        $this->routeCollection->add('test.en', (new Route('/testing/is/fun'))->setDefault('_canonical_route', 'test'));
+        $this->routeCollection->add('test.nl', (new Route('/testen/is/leuk'))->setDefault('_canonical_route', 'test'));
+        $this->routeCollection->add('test.fr', (new Route('/tester/est/amusant'))->setDefault('_canonical_route', 'test'));
+
+        $code = $this->generatorDumper->dump(array(
+            'class' => 'FallbackLocaleLocalizedProjectUrlGenerator',
+        ));
+        file_put_contents($this->testTmpFilepath, $code);
+        include $this->testTmpFilepath;
+
+        $context = new RequestContext('/app.php');
+        $context->setParameter('_locale', 'en_GB');
+        $projectUrlGenerator = new \FallbackLocaleLocalizedProjectUrlGenerator($context, null, null);
+
+        // test with context _locale
+        $this->assertEquals('/app.php/testing/is/fun', $projectUrlGenerator->generate('test'));
+        // test with parameters _locale
+        $this->assertEquals('/app.php/testen/is/leuk', $projectUrlGenerator->generate('test', array('_locale' => 'nl_BE')));
+
+        $projectUrlGenerator = new \FallbackLocaleLocalizedProjectUrlGenerator(new RequestContext('/app.php'), null, 'fr_CA');
+        // test with default locale
+        $this->assertEquals('/app.php/tester/est/amusant', $projectUrlGenerator->generate('test'));
     }
 
     public function testDumpWithTooManyRoutes()