Question

I’m calling an objects method through call_user_func_array to which I pass dynamic string arguments depending on a couple of parameters.

It currently look similar to this:

<?php
class MyObject
{
     public function do_Procedure ($arg1 = "", $arg2 = "")
     { /* do whatever */ }


     public function do_Something_Else (AnotherObject $arg1 = null)
     { /* This method requires the first parameter to
          be an instance of AnotherObject and not String */ }
}

call_user_func_array(array($object, $method), $arguments);
?>

This works for method $method = 'do_Procedure' but if I wanted to call the $method = 'do_Something_Else' method which requires the first argument to be an instance of AnotherObject I get an E_RECOVERABLE_ERROR error.

How do I know which type of instance that should be passed? E.g. if this method requires an object instance but the first processed argument is of string, how do I recognize this so that I can pass null instead or simply skip the call?

Answer 1

$arguments is a array that wil explode to the parameters of the function. If you call the do_Something_Else function the array must either be empty or the first element must be null or a instance of AnotherObject

In all other situations you get a E_RECOVERABLE_ERROR error.

To find out what argument needs to be passed you can use the Reflectionclass

Sample, needs some work to adjust tou your needs:

  protected function Build( $type, $parameters = array( ) )
  {
    if ( $type instanceof \Closure )
      return call_user_func_array( $type, $parameters );

    $reflector = new \ReflectionClass( $type );

    if ( !$reflector->isInstantiable() )
      throw new \Exception( "Resolution target [$type] is not instantiable." );

    $constructor = $reflector->getConstructor();

    if ( is_null( $constructor ) )
      return new $type;

    if( count( $parameters ))
      $dependencies = $parameters; 
    else 
      $dependencies = $this->Dependencies( $constructor->getParameters() );

    return $reflector->newInstanceArgs( $dependencies );
  }

  protected static function Dependencies( $parameters )
  {
    $dependencies = array( );

    foreach ( $parameters as $parameter ) {
      $dependency = $parameter->getClass();

      if ( is_null( $dependency ) ) {
        throw new \Exception( "Unresolvable dependency resolving [$parameter]." );
      }

      $dependencies[] = $this->Resolve( $dependency->name );
    }

    return ( array ) $dependencies;
  }