[4.x] Add children tag (#8990)

src/Providers/ExtensionServiceProvider.php

@@ -151,6 +151,7 @@ class ExtensionServiceProvider extends ServiceProvider
         Tags\Assets::class,
         Tags\Cache::class,
         Tags\Can::class,
+        Tags\Children::class,
         Tags\Collection\Collection::class,
         Tags\Cookie::class,
         Tags\Dd::class,

src/Tags/Children.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Statamic\Tags;
+
+use Statamic\Facades\Site;
+use Statamic\Facades\URL;
+use Statamic\Support\Str;
+
+class Children extends Structure
+{
+    /**
+     * The {{ children }} tag.
+     *
+     * Get any children of the current url
+     *
+     * @return string
+     */
+    public function index()
+    {
+        $this->params->put('from', Str::start(Str::after(URL::getCurrent(), Site::current()->url()), '/'));
+        $this->params->put('max_depth', 1);
+
+        return $this->structure($this->params->get('handle', 'collection::pages'));
+    }
+}

tests/Tags/ChildrenTest.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace Tests\Tags;
+
+use Facades\Tests\Factories\EntryFactory;
+use Mockery;
+use Statamic\Facades\Collection;
+use Statamic\Facades\Parse;
+use Statamic\Facades\Site;
+use Statamic\Tags\Children;
+use Tests\PreventSavingStacheItemsToDisk;
+use Tests\TestCase;
+
+class ChildrenTest extends TestCase
+{
+    use PreventSavingStacheItemsToDisk;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        Site::setConfig(['sites' => [
+            'en' => ['url' => '/', 'locale' => 'en_US'],
+            'fr' => ['url' => '/fr/', 'locale' => 'fr_FR'],
+        ]]);
+    }
+
+    private function tag($tag, $data = [])
+    {
+        return (string) Parse::template($tag, $data);
+    }
+
+    private function setUpEntries()
+    {
+        $collection = tap(Collection::make('pages')->sites(['en', 'fr'])->routes('{slug}')->structureContents(['root' => false]))->save();
+
+        EntryFactory::collection('pages')->id('foo')->data([
+            'title' => 'the foo entry',
+        ])->create();
+
+        EntryFactory::collection('pages')->id('bar')->data([
+            'title' => 'the bar entry',
+        ])->create();
+
+        EntryFactory::collection('pages')->id('fr-foo')->origin('foo')->locale('fr')->data([
+            'title' => 'the french foo entry',
+        ])->create();
+
+        EntryFactory::collection('pages')->id('fr-bar')->origin('foo')->locale('fr')->data([
+            'title' => 'the french bar entry',
+        ])->create();
+
+        $collection->structure()->in('en')->tree([
+            ['entry' => 'foo', 'url' => '/foo', 'children' => [
+                ['entry' => 'bar', 'url' => '/foo/bar'],
+            ]],
+        ])->save();
+
+        $collection->structure()->in('fr')->tree([
+            ['entry' => 'fr-foo', 'url' => '/fr-foo', 'children' => [
+                ['entry' => 'fr-bar', 'url' => '/fr-foo/fr-bar'],
+            ]],
+        ])->save();
+    }
+
+    /** @test */
+    public function it_gets_children_data()
+    {
+        $this->setUpEntries();
+
+        $this->get('/foo');
+
+        $this->assertEquals('the bar entry', $this->tag('{{ children }}{{ title }}{{ /children }}'));
+    }
+
+    /** @test */
+    public function it_gets_children_data_when_in_another_site()
+    {
+        $this->setUpEntries();
+
+        $this->get('/fr/fr-foo');
+
+        $this->assertEquals('the french bar entry', $this->tag('{{ children }}{{ title }}{{ /children }}'));
+    }
+
+    /** @test */
+    public function it_doesnt_affect_children_in_nav()
+    {
+        $this->setUpEntries();
+
+        $mock = Mockery::mock(Children::class);
+        $mock->shouldNotReceive('index');
+
+        $this->app['statamic.tags']['children'] = $mock;
+
+        $this->get('/foo');
+
+        $this->assertEquals('the bar entry', $this->tag('{{ nav }}{{ children }}{{ title }}{{ /children }}{{ /nav }}'));
+
+    }
+}