New when() helper.

src/Illuminate/Foundation/helpers.php

@@ -1047,3 +1047,23 @@ function view($view = null, $data = [], $mergeData = [])
         return $factory->make($view, $data, $mergeData);
     }
 }
+
+if (! function_exists('when')) {
+    /**
+     * Output a value if the given condition is true.
+     *
+     * @param  bool  $condition
+     * @param  string  $output,
+     * @param  bool  $escape
+     * @return void
+     *
+     * @throws \Symfony\Component\HttpKernel\Exception\HttpException
+     * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
+     */
+    function when($condition, $output, $escape = false)
+    {
+        if ($condition) {
+            echo $escape ? e($output) : $output;
+        }
+    }
+}

src/Illuminate/View/Compilers/BladeCompiler.php

@@ -16,6 +16,7 @@ class BladeCompiler extends Compiler implements CompilerInterface
 {
     use Concerns\CompilesAuthorizations,
         Concerns\CompilesClasses,
+        Concerns\CompilesWhens,
         Concerns\CompilesComments,
         Concerns\CompilesComponents,
         Concerns\CompilesConditionals,

src/Illuminate/View/Compilers/Concerns/CompilesWhens.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Illuminate\View\Compilers\Concerns;
+
+trait CompilesWhens
+{
+    /**
+     * Compile the 'when' statement into valid PHP.
+     *
+     * @param  string  $expression
+     * @param  string  $output
+     * @param  bool  $escape
+     * @return string
+     */
+    protected function compileWhen($expression)
+    {
+        $expression = $expression == '()' ? "(false,'',false)" : $expression;
+
+        return "<?php when{$expression}; ?>";
+    }
+}

tests/View/Blade/BladeWhenTest.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Illuminate\Tests\View\Blade;
+
+class BladeWhenTest extends AbstractBladeTestCase
+{
+    public function testWhenStatmentsAreCompiledRaw()
+    {
+        $string = "<span @when(true, 'disabled=\"disabled\"', false)></span>";
+        $expected = "<span <?php when(true, 'disabled=\"disabled\"', false); ?>></span>";
+        $this->assertEquals($expected, $this->compiler->compileString($string));
+    }
+
+    public function testWhenStatementsAreCompiledEmpty()
+    {
+        $string = '<span @when()></span>';
+        $expected = "<span <?php when(false,'',false); ?>></span>";
+        $this->assertEquals($expected, $this->compiler->compileString($string));
+    }
+}