Add HasItemActiveContainer trait for item active container functional…

…ity. (#180)

src/Attribute/Tag/HasItemActiveContainer.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPForge\Html\Attribute\Tag;
+
+use InvalidArgumentException;
+use PHPForge\Html\Helper\CssClass;
+
+/**
+ * Is used by widgets that implement the item active container methods.
+ */
+trait HasItemActiveContainer
+{
+    protected array $itemActiveContainerAttributes = [];
+
+    public function itemActiveContainer(bool $value): static
+    {
+        $new = clone $this;
+        $new->itemActiveContainer = $value;
+
+        return $new;
+    }
+
+    public function itemActiveContainerAttributes(array $value): static
+    {
+        $new = clone $this;
+        $new->itemActiveContainerAttributes = $value;
+
+        return $new;
+    }
+
+    public function itemActiveContainerClass(string $value, bool $override = false): static
+    {
+        $new = clone $this;
+        CssClass::add($new->itemActiveContainerAttributes, $value, $override);
+
+        return $new;
+    }
+
+    public function itemActiveContainerTag(string $value): static
+    {
+        if ($value === '') {
+            throw new InvalidArgumentException(
+                sprintf(
+                    'The item container tag must be a non-empty string. "%s" given.',
+                    $value,
+                ),
+            );
+        }
+
+        $new = clone $this;
+        $new->itemActiveContainerTag = $value;
+
+        return $new;
+    }
+}

tests/Attribute/Tag/HasItemActiveContainerTest.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPForge\Html\Tests\Attribute\Tag;
+
+use InvalidArgumentException;
+use PHPForge\Html\Attribute\Tag\HasItemActiveContainer;
+use PHPUnit\Framework\TestCase;
+
+final class HasItemActiveContainerTest extends TestCase
+{
+    public function testClass(): void
+    {
+        $instance = new class () {
+            use HasItemActiveContainer;
+
+            protected bool $itemActiveContainer = false;
+            protected array $itemActiveContainerAttributes = [];
+            protected string $itemActiveContainerTag = 'div';
+
+            public function getItemActiveContainerClass(): string
+            {
+                return $this->itemActiveContainerAttributes['class'] ?? '';
+            }
+        };
+
+        $this->assertEmpty($instance->getItemActiveContainerClass());
+
+        $instance = $instance->itemActiveContainerClass('class');
+
+        $this->assertSame('class', $instance->getItemActiveContainerClass());
+
+        $instance = $instance->itemActiveContainerClass('class-1');
+
+        $this->assertSame('class class-1', $instance->getItemActiveContainerClass());
+
+        $instance = $instance->itemActiveContainerClass('override-class', true);
+
+        $this->assertSame('override-class', $instance->getItemActiveContainerClass());
+    }
+
+    public function testException(): void
+    {
+        $instance = new class () {
+            use HasItemActiveContainer;
+
+            protected string $itemActiveContainerTag = '';
+        };
+
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The item container tag must be a non-empty string.');
+
+        $instance->itemActiveContainerTag('');
+    }
+
+    public function testImmutability(): void
+    {
+        $instance = new class () {
+            use HasItemActiveContainer;
+
+            protected bool $itemActiveContainer = false;
+            protected array $itemActiveContainerAttributes = [];
+            protected string $itemActiveContainerTag = 'div';
+        };
+
+        $this->assertNotSame($instance, $instance->itemActiveContainer(false));
+        $this->assertNotSame($instance, $instance->itemActiveContainerAttributes([]));
+        $this->assertNotSame($instance, $instance->itemActiveContainerClass(''));
+        $this->assertNotSame($instance, $instance->itemActiveContainerTag('span'));
+    }
+}