add if method

src/Illuminate/View/Compilers/BladeCompiler.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\View\Compilers;
 
+use Closure;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
 
@@ -345,6 +346,40 @@ public function getExtensions()
         return $this->extensions;
     }
 
+    /**
+     * Register an "if" statement directive.
+     *
+     * @param  string  $name
+     * @param  \Closrue  $callback
+     * @return void
+     */
+    public function if($name, Closure $callback)
+    {
+        $this->conditions[$name] = $callback;
+
+        $this->directive($name, function ($expression) use ($name) {
+            return $expression
+                    ? "<?php if (\Illuminate\Support\Facades\Blade::check('{$name}', {$expression})): ?>"
+                    : "<?php if (\Illuminate\Support\Facades\Blade::check('{$name}')): ?>";
+        });
+
+        $this->directive('end'.$name, function () {
+            return "<?php endif; ?>";
+        });
+    }
+
+    /**
+     * Check the result of a condition.
+     *
+     * @param  string  $name
+     * @param  array  $parameters
+     * @return bool
+     */
+    public function check($name, ...$parameters)
+    {
+        return call_user_func($this->conditions[$name], ...$parameters);
+    }
+
     /**
      * Register a handler for custom directives.
      *

tests/View/Blade/BladeCustomTest.php

@@ -60,4 +60,17 @@ public function testCustomExtensionOverwritesCore()
         $expected = '<?php custom(); ?>';
         $this->assertEquals($expected, $this->compiler->compileString($string));
     }
+
+    public function testCustomConditions()
+    {
+        $this->compiler->if('custom', function ($user) {
+            return true;
+        });
+
+        $string = '@custom($user)
+@endcustom';
+        $expected = '<?php if (\Illuminate\Support\Facades\Blade::check(\'custom\', $user)): ?>
+<?php endif; ?>';
+        $this->assertEquals($expected, $this->compiler->compileString($string));
+    }
 }