code/command/mixin/mixin.php
public function hasCommandHandler($handler)
    {
        if($handler instanceof CommandHandlerInterface) {
            $identifier = $handler->getIdentifier();
        } else {
            $identifier = $this->getIdentifier($handler);
        }

        return $this->getCommandChain()->getHandlers()->hasIdentifier($identifier);
    }
public function hasCommandHandler($handler)
    {
        if($handler instanceof CommandHandlerInterface) {
            $identifier = $handler->getIdentifier();
        } else {
            $identifier = $this->getIdentifier($handler);
        }

        return $this->getCommandChain()->getHandlers()->hasIdentifier($identifier);
    }
public function hasCommandHandler ( $ handler ) { if ( $ handler instanceof CommandHandlerInterface ) { $ identifier = $ handler -> getIdentifier ( ) ; } else { $ identifier = $ this -> getIdentifier ( $ handler ) ; } return $ this -> getCommandChain ( ) -> getHandlers ( ) -> hasIdentifier ( $ identifier ) ; }
Check if a command handler exists

@param  mixed $handler An object that implements CommandHandlerInterface, an ObjectIdentifier
or valid identifier string
@return  boolean TRUE if the behavior exists, FALSE otherwise
Check if a command handler exists