public function BackendBase::registerFunction in SCSS Compiler 1.0.x

Register a PHP callback function bridge that can be used in SCSS code.

It is recommended to register all needed functions before the compiler is ran for the first time. If a function is registered after the compiler's first run, then the behavior is undefined.

Parameters

callable $cb: The PHP function to call when bridged from SCSS.

Optional and pass-by-reference parameters aren't supported.

string|null $name: The name of the function as it should be used in the compiled language. This value must be a valid PHP identifier.

Optional unless an anonymous function is supplied (default: NULL).

Throws

\InvalidArgumentException If a bad function name is supplied, or a callback with an optional or pass-by-reference parameter is supplied.

Overrides BackendInterface::registerFunction

File

src/BackendBase.php, line 183

Class

BackendBase

Provides a base compiler backend implementation.

Namespace

Drupal\compiler_scss

Code

public function registerFunction(callable $callback, $name = NULL) {

  // Use reflection to facilitate registering the supplied callback function.
  $reflection = new \ReflectionFunction($callback);

  // Attempt to resolve the name of the callback function.
  if (!$reflection
    ->isClosure()) {
    $name = $reflection
      ->getShortName();
  }
  elseif (preg_match(self::IDENT_EXPR, $name) !== 1) {
    throw new \InvalidArgumentException('Bad function name');
  }

  // Fetch a list of parameter names for this function.
  $params = array_map(function ($param) {

    // TODO: We don't yet support optional parameters.
    //
    // Pass-by-reference parameters will never be supported across languages.
    if ($param
      ->isOptional() || $param
      ->isPassedByReference()) {
      throw new \InvalidArgumentException('Optional or pass-by-reference parameters are not supported for callback functions');
    }
    return $param
      ->getName();
  }, $reflection
    ->getParameters());

  // Construct the function's SASS signature using the parameter list.
  $signature = implode(', ', array_map(function ($param) {
    return '$' . $param;
  }, $params));
  $this->functions[$name] = (object) [
    'callback' => $callback,
    'name' => $name,
    'params' => $params,
    'signature' => $signature,
  ];
}