新增classnames函数 css样式名生成器

src/helper.php

@@ -64,4 +64,30 @@ function trait_uses_recursive($trait)
 
         return $traits;
     }
+}
+if (!function_exists('classnames')) {
+    /**
+     * css样式名生成器
+     * classnames("foo", "bar"); // => "foo bar"
+     * classnames("foo", [ "bar"=> true ]); // => "foo bar"
+     * classnames([ "foo-bar"=> true ]); // => "foo-bar"
+     * classnames([ "foo-bar"=> false ]); // => "
+     * classnames([ "foo" => true ], [ "bar"=> true ]); // => "foo bar"
+     * classnames([ "foo" => true, "bar"=> true ]); // => "foo bar"
+     * classnames("foo", [ "bar"=> true, "duck"=> false ], "baz", [ "quux"=> true ]); // => "foo bar baz quux"
+     * classnames(null, false, "bar", 0, 1, [ "baz"=> null ]); // => "bar 1"
+     */
+    function classnames()
+    {
+        $args    = func_get_args();
+        $classes = array_map(function ($arg) {
+            if (is_array($arg)) {
+                return implode(" ", array_filter(array_map(function ($expression, $class) {
+                    return $expression ? $class : false;
+                }, $arg, array_keys($arg))));
+            }
+            return $arg;
+        }, $args);
+        return implode(" ", array_filter($classes));
+    }
 }