Working on a REST API, critique requested

[eluser]Yorick Peterse[/eluser]
So I am working on a REST API for an application of mine. Since this is the first time I'm making a REST API I'd like to receive some critique and tips. Right now my API controller looks like the following piece of code:

Controller

Code:

<?php
class Api extends Controller {
    
    // Constructor function
    function __construct() {
    parent::Controller();
    }
    /**
     * Main REST functions
     *
     * By adding these functions to the URL, Flork will determine what has to be executed.
     */
    
    // Function to add data
    function post() {
    
    }
    
    // Function to get data
    function get() {
    
    }
    
    // Function to update data
    function put() {
    
    }
    
    // Function to delete data
    function delete() {
    
    }
    
    /**
     * General functions
     *
     * General functions, such as generating messages.
     */
    
    // Function to generate a response message
    private function sendResponse($status = '200',$body = '',$content_type = 'text/html') {
    
    }
    
    // Function to generate a HTTP response code, based on the $status variable defined in sendResponse()
    private function getResponseCode($status) {    
    // Create an array containing all response codes and their messages
    $codes = array (
        100 => 'Continue',
            101 => 'Switching Protocols',
            200 => 'OK',
            201 => 'Created',
            202 => 'Accepted',
            203 => 'Non-Authoritative Information',
            204 => 'No Content',
            205 => 'Reset Content',
            206 => 'Partial Content',
            300 => 'Multiple Choices',
            301 => 'Moved Permanently',
            302 => 'Found',
            303 => 'See Other',
            304 => 'Not Modified',
            305 => 'Use Proxy',
            306 => '(Unused)',
            307 => 'Temporary Redirect',
            400 => 'Bad Request',
            401 => 'Unauthorized',
            402 => 'Payment Required',
            403 => 'Forbidden',
            404 => 'Not Found',
            405 => 'Method Not Allowed',
            406 => 'Not Acceptable',
            407 => 'Proxy Authentication Required',
            408 => 'Request Timeout',
            409 => 'Conflict',
            410 => 'Gone',
            411 => 'Length Required',
            412 => 'Precondition Failed',
            413 => 'Request Entity Too Large',
            414 => 'Request-URI Too Long',
            415 => 'Unsupported Media Type',
            416 => 'Requested Range Not Satisfiable',
            417 => 'Expectation Failed',
            500 => 'Internal Server Error',
            501 => 'Not Implemented',
            502 => 'Bad Gateway',
            503 => 'Service Unavailable',
            504 => 'Gateway Timeout',
            505 => 'HTTP Version Not Supported'        
    );
    
    // Verify if the status message has been set
    if(isset($codes[$status])) {
        // Return the response code
        return $codes[$status];
    }    
    }
    
    // Function to flush all data
    private function flushData() {
    
    }
    
    // Function to verify the request
    private function verifyRequest() {
    
    }
}
?>

Model

Code:

<?php

class Model_api extends Model {
    
    // Constructor function
    function __construct() {
    parent::Model();
    }
    // Function to output data in XML or JSON
    function getData($table,$id,$format) {
    
    }
    
    // Function to store the data that was sent using an HTTP request.
    function postData($table,$data) {
    
    }
    
    // Function to update existing data
    function putData($table,$id,$data) {
    
    }
    
    // Function to delete data
    function deleteData($table,$id) {
    
    }
}
?>

Keep in mind that the controller looks really rough and will most likely be changed a billion times. However, what I'm asking of you is to look at it and give any information that could be useful, finding the right info about REST is quite hard.