writing-an-api-2.php

<?php

public function callOldVersion($argumentsList) {

	//If they have requested a NON current API version
	if (APIHelpers::$API_VERSION != APIHelpers::CURRENT_API_VERSION) {

		//get the name of the method that they have called
		$actionName = $this->dispatcher->getActionName();

		//build the name of the legacy action method
		$legacyActionName = $actionName . APIHelpers::$API_VERSION;

		//if there is a legacy version..
		if (method_exists($this->oldApiService, $legacyActionName)) {

			//iterate through previous versions, and convert the arguments
			for ($toVersion = APIHelpers::$API_VERSION;  $toVersion < APIHelpers::CURRENT_API_VERSION; $toVersion++) {

				$fromVersion = $toVersion + 1;
				
				//echo "Convert from " . $fromVersion . " to " . $toVersion;
	
				//build the convertor method name
				$convertorName = $actionName . $fromVersion . "to" . $toVersion;

				//if a convertor with that name exists
				if (method_exists("ArgumentConvertors", $convertorName)) {

					//convert the arguments
					$argumentsList = call_user_func_array(array("ArgumentConvertors", $convertorName), $argumentsList);
				}

				//otherwise the legacy version must take the same parameters
			}

			$response = call_user_func_array(array($this->oldApiService, $legacyActionName), $argumentsList);

			return $response;
		}

		//indicate that there was no legacy handler so we should just call the normal method
		return false;
	}
}