/**
* Used to include JavaScript libraries.
*
* When the $lib parameter is given, the function will ensure that the
* named library or libraries is loaded onto the page - either in the
* HTML <head>, just after the header, or at an arbitrary later point in
* the page, depending on where this function is called.
*
* Libraries will not be included more than once, so this works like
* require_once in PHP.
*
* There are two special-case calls to this function from print_header which are
* internal to weblib and use the second $extracthtml parameter:
* $extracthtml = 1: this is used before printing the header.
* It returns the script tag code that should go inside the <head>.
* $extracthtml = 2: this is used after printing the header and handles any
* require_js calls that occurred within the header itself.
*
* @param mixed $lib The library or libraries to load (a string or array of strings)
* There are three way to specify the library:
* 1. a shorname like 'yui_yahoo'. The list of recognised values is in lib/ajax/ajaxlib.php
* 2. the path to the library relative to wwwroot, for example 'lib/javascript-static.js'
* 3. (legacy) a full URL like $CFG->wwwroot . '/lib/javascript-static.js'.
* @param int $extracthtml Private. For internal weblib use only.
* @return mixed No return value (except when doing the internal $extracthtml
* calls, when it returns html code).
*/
function require_js($lib, $extracthtml = 0)
{
global $CFG;
static $loadlibs = array();
static $state = REQUIREJS_BEFOREHEADER;
static $latecode = '';
if (!empty($lib)) {
// Add the lib to the list of libs to be loaded, if it isn't already
// in the list.
if (is_array($lib)) {
foreach ($lib as $singlelib) {
require_js($singlelib);
}
} else {
$libpath = ajax_get_lib($lib);
if (array_search($libpath, $loadlibs) === false) {
$loadlibs[] = $libpath;
// For state other than 0 we need to take action as well as just
// adding it to loadlibs
if ($state != REQUIREJS_BEFOREHEADER) {
// Get the script statement for this library
$scriptstatement = get_require_js_code(array($libpath));
if ($state == REQUIREJS_AFTERHEADER) {
// After the header, print it immediately
print $scriptstatement;
} else {
// Haven't finished the header yet. Add it after the
// header
$latecode .= $scriptstatement;
}
}
}
}
} else {
if ($extracthtml == 1) {
if ($state !== REQUIREJS_BEFOREHEADER) {
debugging('Incorrect state in require_js (expected BEFOREHEADER): be careful not to call with empty $lib (except in print_header)');
} else {
$state = REQUIREJS_INHEADER;
}
return get_require_js_code($loadlibs);
} else {
if ($extracthtml == 2) {
if ($state !== REQUIREJS_INHEADER) {
debugging('Incorrect state in require_js (expected INHEADER): be careful not to call with empty $lib (except in print_header)');
return '';
} else {
$state = REQUIREJS_AFTERHEADER;
return $latecode;
}
} else {
debugging('Unexpected value for $extracthtml');
}
}
}
}
/**
* add includes (js and css) into uploaded files
* before returning them, useful for themes and utf.js includes
* @param string text - text to search and replace
* @return string - text with added head includes
*/
function file_modify_html_header($text)
{
// first look for <head> tag
global $CFG;
$stylesheetshtml = '';
foreach ($CFG->stylesheets as $stylesheet) {
$stylesheetshtml .= '<link rel="stylesheet" type="text/css" href="' . $stylesheet . '" />' . "\n";
}
$ufo = '';
if (filter_is_enabled('filter/mediaplugin')) {
// this script is needed by most media filter plugins.
$ufo = get_require_js_code(array($CFG->wwwroot . '/lib/ufo.js'));
}
preg_match('/\\<head\\>|\\<HEAD\\>/', $text, $matches);
if ($matches) {
$replacement = '<head>' . $ufo . $stylesheetshtml;
$text = preg_replace('/\\<head\\>|\\<HEAD\\>/', $replacement, $text, 1);
return $text;
}
// if not, look for <html> tag, and stick <head> right after
preg_match('/\\<html\\>|\\<HTML\\>/', $text, $matches);
if ($matches) {
// replace <html> tag with <html><head>includes</head>
$replacement = '<html>' . "\n" . '<head>' . $ufo . $stylesheetshtml . '</head>';
$text = preg_replace('/\\<html\\>|\\<HTML\\>/', $replacement, $text, 1);
return $text;
}
// if not, look for <body> tag, and stick <head> before body
preg_match('/\\<body\\>|\\<BODY\\>/', $text, $matches);
if ($matches) {
$replacement = '<head>' . $ufo . $stylesheetshtml . '</head>' . "\n" . '<body>';
$text = preg_replace('/\\<body\\>|\\<BODY\\>/', $replacement, $text, 1);
return $text;
}
// if not, just stick a <head> tag at the beginning
$text = '<head>' . $ufo . $stylesheetshtml . '</head>' . "\n" . $text;
return $text;
}
