functions.php

<?php

function url_for($script_path) {
  // add the leading '/' if not present
  if($script_path[0] != '/') {
    $script_path = "/" . $script_path;
  }
  return WWW_ROOT . $script_path;
}

function u($string="") {
  return urlencode($string);
}

function raw_u($string="") {
  return rawurlencode($string);
}

function h($string="") {
  return htmlspecialchars($string);
}

function error_404() {
  header($_SERVER["SERVER_PROTOCOL"] . " 404 Not Found");
  exit();
}

function error_500() {
  header($_SERVER["SERVER_PROTOCOL"] . " 500 Internal Server Error");
  exit();
}

function redirect_to($location) {
  header("Location: " . $location);
  exit;
}

function is_post_request() {
  return $_SERVER['REQUEST_METHOD'] == 'POST';
}

function is_get_request() {
  return $_SERVER['REQUEST_METHOD'] == 'GET';
}

function display_errors($errors=array()) {
    $output = '';
    if(!empty($errors)) {
        $output .= "<div class=\"errors\">";
        $output .= "Please fix the following errors:";
        $output .= "<ul>";
        foreach($errors as $error) {
            $output .= "<li>" . h($error) . "</li>";
        }
        $output .= "</ul>";
        $output .= "</div>";
    }
    return $output;
}

//------------------------------------------------------------------------
//	Used to convert a user-created URL into an embeddable URL.  
//	Example: The typical URL pasted in from users will look like this: https://www.youtube.com/watch?v=CgSs3OvTnUQ
// 			 But this will not work in an embedded iFrame and so must be converted to: https://www.youtube.com/embed/CgSs3OvTnUQ
//
function mangleurl($url, $urltype = "") {
	if (strcasecmp($urltype, 'url') == 0 and strcasecmp(substr($url, 0, 3), 'http') != 0) {
		$url = 'http://' . $url;
	}
	$urlchunks = parse_url(trim($url));

	if (DEBUG_MODE == 'ONxx') {
		echo 'DEBUG MODE: ' . dirname(__FILE__).'.mangleurl()<br/>'; 
		echo var_dump($url) . '<br/>';
		echo var_dump($urlchunks) . '<br/>';
		echo '<br/>';
		}
	
	$baseurl = $url;		// in case we don't need to do anything, send back what we were given
	
	if (strpos(strtolower($urlchunks['host']), 'youtube') > 0) {
	    $baseurl = $urlchunks['scheme']."://".$urlchunks['host']."/embed/";
		if (strtolower(substr($urlchunks['query'], 0, 2)) == "v=") {
			$youtubeid = substr($urlchunks['query'], 2);
		}
		else {
			$youtubeid = $urlchunks['query'];
		}
		
		return $baseurl.$youtubeid;
	}

	if (strcasecmp(strtolower($urlchunks['host']), 'drive.google.com') == 0) {
		if (strcasecmp($urltype, 'image') == 0) {
			$baseurl  = $urlchunks['scheme']."://".$urlchunks['host']."/thumbnail?";
			$baseurl .= $urlchunks['query'].'&sz=w400-h400';
		}
		else {		
			$baseurl = 'https://docs.google.com/document/d/' . substr($urlchunks['query'], 3) . '/edit';
		}
	}

	return $baseurl;
}


//------------------------------------------------------------------------
//	An item entry from the DB might have multiple URLs sepearated by ';' characters
//	This function takes that string and returns an array of those items
//	it will always return an array that is at least one item in size
//	Example https://www.youtube.com/watch?v=Md0CGAtOPEw;https://www.youtube.com/watch?v=0uPQjgfjl2Q;https://www.youtube.com/watch?v=yA83mhXV3iU;https://www.youtube.com/watch?v=pwFy7eP-IGA

function handlemultipleitems($item) {
	$urlarray = explode(';',$item);

	// if (DEBUG_MODE == 'ON') {
		// echo 'DEBUG MODE: ' . dirname(__FILE__).'.handlemultipleitems()<br/>'; 
		// echo var_dump($urlarray);
		// echo '<br/>';
		// }
			
	return $urlarray;
}

//------------------------------------------------------------------------
//	An item entry from the DB might have multiple URLs sepearated by ';' characters
//	This function counts how many items are in that long string
//	it can return 0 if the string is empty
//	Example https://www.youtube.com/watch?v=Md0CGAtOPEw;https://www.youtube.com/watch?v=0uPQjgfjl2Q;https://www.youtube.com/watch?v=yA83mhXV3iU;https://www.youtube.com/watch?v=pwFy7eP-IGA

function countitems($item) {
	$urlarray = explode(';',$item);
	$ctr = 0;

	 // if (DEBUG_MODE == 'ON') {
		// echo 'DEBUG MODE: ' . dirname(__FILE__).'.countitems()<br/>'; 
		// echo var_dump($urlarray);
		// echo count($urlarray);
		// echo '<br/>';
		// }
			
	foreach ($urlarray as $subitem) {
		if (trim($subitem) != '') {
			$ctr += 1;
		}
	}
		
	return $ctr;
}

  function is_logged_in() {
    // Having a admin_id in the session serves a dual-purpose:
    // - Its presence indicates the admin is logged in.
    // - Its value tells which admin for looking up their record.
    if (!isset($_SESSION['logged_in'])) {return false;}
	if ($_SESSION['logged_in'] != true) {return false;}
	return true;
  }

  function is_super_admin() {
    // Having a admin_id in the session serves a dual-purpose:
    // - Its presence indicates the admin is logged in.
    // - Its value tells which admin for looking up their record.
	if (!isset($_SESSION['logged_in'])) {return false;}
	if (!isset($_SESSION['role'])) {return false;}
    return ($_SESSION['logged_in'] == true and $_SESSION['role'] == 'SUPER-ADMIN');
  }  
  
  function is_admin() {
    // Having a admin_id in the session serves a dual-purpose:
    // - Its presence indicates the admin is logged in.
    // - Its value tells which admin for looking up their record.
	if (!isset($_SESSION['logged_in'])) {return false;}
	if (!isset($_SESSION['role'])) {return false;}
	if (is_super_admin() == true) {return true;}
    return ($_SESSION['logged_in'] == true and $_SESSION['role'] == 'ADMIN');
  }  
  
  function is_user() {
    // Having a admin_id in the session serves a dual-purpose:
    // - Its presence indicates the admin is logged in.
    // - Its value tells which admin for looking up their record.
	if (is_super_admin() == true) {return true;}
	if (is_admin() == true) {return true;}
	if (!isset($_SESSION['logged_in'])) {return true;}
	if (!isset($_SESSION['role'])) {
		$_SESSION['role'] = 'USER';
		return true;
		}
    return ($_SESSION['logged_in'] == true and $_SESSION['role'] == 'USER');
  }  


function show_flash_message() {
  if (isset($_SESSION['action_message'])) {
    $message = $_SESSION['action_message'];
    unset($_SESSION['action_message']);
    return $message;
  }
  return NULL;
}

?>