system/classes/restresponse.php

<?php
namespace Habari;

class RestResponse
{
  protected $response;

  public function __construct($response) {
    $this->response = $response;
  }

  public function out() {
    $accept = $this->get_accept();
    header('content-type: ' . $accept);
    echo $this->get();
  }

  public function get_best_mime($mime_types = null) {
    // Values will be stored in this array
    $accept_types = array();

    // Accept header is case insensitive, and whitespace isn’t important
    $accept = strtolower(str_replace(' ', '', $_SERVER['HTTP_ACCEPT']));
    // divide it into parts in the place of a ","
    $accept = explode(',', $accept);
    foreach ($accept as $a) {
      // the default quality is 1.
      $q = 1;
      // check if there is a different quality
      if (strpos($a, ';q=')) {
        // divide "mime/type;q=X" into two parts: "mime/type" and "X"
        list($a, $q) = explode(';q=', $a);
      }
      // mime-type $a is accepted with the quality $q
      // WARNING: $q == 0 means, that mime-type isn’t supported!
      $accept_types[$a] = $q;
    }
    arsort($accept_types);

    // if no parameter was passed, just return parsed data
    if (!$mime_types) {
      return $accept_types;
    }

    $mime_types = array_map('strtolower', (array)$mime_types);

    // let's check our supported types:
    foreach ($accept_types as $mime => $q) {
      if ($q && in_array($mime, $mime_types)) {
        return $mime;
      }
    }
    // no mime-type found
    return null;
  }

  public function get_mime_list() {
    static $mimelist = null;
    if(is_null($mimelist)) {
      $mimelist = array(
        'text/plain' => array($this, 'convert_text_plain'),
        'text/html' => array($this, 'convert_text_html'),
        'application/json' => array($this, 'convert_applicaton_json'),
        'application/xml' => array($this, 'convert_application_xml'),
      );
      $mimelist = Plugins::filter('rest_mime_list', $mimelist);
    }
    return $mimelist;
  }

  public function get_accept()
  {
    $mimelist = $this->get_mime_list();
    $accept = $this->get_best_mime(array_keys($mimelist));
    return $accept;
  }

  public function get() {
    $mimelist = $this->get_mime_list();
    $accept = $this->get_accept();
    if(is_string($this->response)) {
      $response = $this->response;
    }
    elseif(is_array($this->response)) {
      $response = $mimelist[$accept]($this->response);
    }
    elseif($this->response instanceof DOMElement) {
      $response = $mimelist[$accept]($this->response);
    }

    $response = Plugins::filter('rest_response', $response, $accept, $this->response);
    return $response;
  }
}