REST services for industrious 1980s executives on a budget.

budgetrest.class.php

<?php

class BudgetRest {
  /**
   *
   */
  public function __construct() {
    if (!empty($_SERVER['PATH_INFO'])) {
      $sections = explode('/', trim($_SERVER['PATH_INFO'], '/'));
    } elseif (!empty($_SERVER['REQUEST_URI']) && !empty($_SERVER['PHP_SELF'])) {
      $sections = str_replace($_SERVER['PHP_SELF'], '', $_SERVER['REQUEST_URI']);
      $sections = str_replace('//', '/', $sections);
      $sections = trim($sections, '?');
      $sections = explode('/', trim($sections, '/'));
    } else {
      $this->error(404);
    }

    $this->base_url = "//{$_SERVER['HTTP_HOST']}" . dirname($_SERVER['PHP_SELF']);

    $method = strtolower(array_shift($sections));
    $explicit_method = $method . '_' . strtolower($_SERVER['REQUEST_METHOD']);

    if (method_exists($this, $explicit_method)) {
      $method = $explicit_method;
    }

    if (strpos($method, '_') !== 0 && method_exists($this, $method)) {
      try {
        $data = call_user_func_array(array($this, $method), $sections);
        $this->_json($data);
      } catch(\Exception $e) {
        $this->_error(500);
      }
    } else {
      $this->_error(404);
    }
  }


    /**
     *
     */
    protected function _error($code=500) {
      switch($code) {
      case 404:
        header("HTTP/1.0 404 Not Found");
        break;

      case 500:
      default:
        header("HTTP/1.0 Internal Server Error");
        break;
      }

      exit(1);
    }


    /**
     *
     */
    protected function _json($data) {
      $this->_sent_data = TRUE;

      header('Content-Type: application/json');

      if (is_array($data)) {
        $data = $this->_sanitize_json($data);
        echo json_encode($data);
      } else {
        echo "null";
      }

      exit(0);
    }
  }