lib/csslib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * This file contains CSS file serving functions.
  19  *
  20  * NOTE: these functions are not expected to be used from any addons.
  21  *
  22  * @package core
  23  * @copyright 2012 Sam Hemelryk
  24  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 if (!defined('THEME_DESIGNER_CACHE_LIFETIME')) {
  30     // This can be also set in config.php file,
  31     // it needs to be higher than the time it takes to generate all CSS content.
  32     define('THEME_DESIGNER_CACHE_LIFETIME', 10);
  33 }
  34
  35 /**
  36  * Stores CSS in a file at the given path.
  37  *
  38  * This function either succeeds or throws an exception.
  39  *
  40  * @param theme_config $theme The theme that the CSS belongs to.
  41  * @param string $csspath The path to store the CSS at.
  42  * @param string $csscontent the complete CSS in one string.
  43  */
  44 function css_store_css(theme_config $theme, $csspath, $csscontent) {
  45     global $CFG;
  46
  47     clearstatcache();
  48     if (!file_exists(dirname($csspath))) {
  49         @mkdir(dirname($csspath), $CFG->directorypermissions, true);
  50     }
  51
  52     // Prevent serving of incomplete file from concurrent request,
  53     // the rename() should be more atomic than fwrite().
  54     ignore_user_abort(true);
  55
  56     // First up write out the single file for all those using decent browsers.
  57     css_write_file($csspath, $csscontent);
  58
  59     ignore_user_abort(false);
  60     if (connection_aborted()) {
  61         die;
  62     }
  63 }
  64
  65 /**
  66  * Writes a CSS file.
  67  *
  68  * @param string $filename
  69  * @param string $content
  70  */
  71 function css_write_file($filename, $content) {
  72     global $CFG;
  73     if ($fp = fopen($filename.'.tmp', 'xb')) {
  74         fwrite($fp, $content);
  75         fclose($fp);
  76         rename($filename.'.tmp', $filename);
  77         @chmod($filename, $CFG->filepermissions);
  78         @unlink($filename.'.tmp'); // Just in case anything fails.
  79     }
  80 }
  81
  82 /**
  83  * Sends a cached CSS file
  84  *
  85  * This function sends the cached CSS file. Remember it is generated on the first
  86  * request, then optimised/minified, and finally cached for serving.
  87  *
  88  * @param string $csspath The path to the CSS file we want to serve.
  89  * @param string $etag The revision to make sure we utilise any caches.
  90  */
  91 function css_send_cached_css($csspath, $etag) {
  92     // 90 days only - based on Moodle point release cadence being every 3 months.
  93     $lifetime = 60 * 60 * 24 * 90;
  94
  95     header('Etag: "'.$etag.'"');
  96     header('Content-Disposition: inline; filename="styles.php"');
  97     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($csspath)) .' GMT');
  98     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
  99     header('Pragma: ');
 100     header('Cache-Control: public, max-age='.$lifetime.', immutable');
 101     header('Accept-Ranges: none');
 102     header('Content-Type: text/css; charset=utf-8');
 103     if (!min_enable_zlib_compression()) {
 104         header('Content-Length: '.filesize($csspath));
 105     }
 106
 107     readfile($csspath);
 108     die;
 109 }
 110
 111 /**
 112  * Sends a cached CSS content
 113  *
 114  * @param string $csscontent The actual CSS markup.
 115  * @param string $etag The revision to make sure we utilise any caches.
 116  */
 117 function css_send_cached_css_content($csscontent, $etag) {
 118     // 90 days only - based on Moodle point release cadence being every 3 months.
 119     $lifetime = 60 * 60 * 24 * 90;
 120
 121     header('Etag: "'.$etag.'"');
 122     header('Content-Disposition: inline; filename="styles.php"');
 123     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 124     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 125     header('Pragma: ');
 126     header('Cache-Control: public, max-age='.$lifetime.', immutable');
 127     header('Accept-Ranges: none');
 128     header('Content-Type: text/css; charset=utf-8');
 129     if (!min_enable_zlib_compression()) {
 130         header('Content-Length: '.strlen($csscontent));
 131     }
 132
 133     echo($csscontent);
 134     die;
 135 }
 136
 137 /**
 138  * Sends CSS directly and disables all caching.
 139  * The Content-Length of the body is also included, but the script is not ended.
 140  *
 141  * @param string $css The CSS content to send
 142  */
 143 function css_send_temporary_css($css) {
 144     header('Cache-Control: no-cache, no-store, must-revalidate');
 145     header('Pragma: no-cache');
 146     header('Expires: 0');
 147     header('Content-Disposition: inline; filename="styles_debug.php"');
 148     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 149     header('Accept-Ranges: none');
 150     header('Content-Type: text/css; charset=utf-8');
 151     header('Content-Length: ' . strlen($css));
 152
 153     echo $css;
 154 }
 155
 156 /**
 157  * Sends CSS directly without caching it.
 158  *
 159  * This function takes a raw CSS string, optimises it if required, and then
 160  * serves it.
 161  * Turning both themedesignermode and CSS optimiser on at the same time is awful
 162  * for performance because of the optimiser running here. However it was done so
 163  * that theme designers could utilise the optimised output during development to
 164  * help them optimise their CSS... not that they should write lazy CSS.
 165  *
 166  * @param string $css
 167  */
 168 function css_send_uncached_css($css) {
 169     header('Content-Disposition: inline; filename="styles_debug.php"');
 170     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 171     header('Expires: '. gmdate('D, d M Y H:i:s', time() + THEME_DESIGNER_CACHE_LIFETIME) .' GMT');
 172     header('Pragma: ');
 173     header('Accept-Ranges: none');
 174     header('Content-Type: text/css; charset=utf-8');
 175
 176     if (is_array($css)) {
 177         $css = implode("\n\n", $css);
 178     }
 179     echo $css;
 180     die;
 181 }
 182
 183 /**
 184  * Send file not modified headers
 185  *
 186  * @param int $lastmodified
 187  * @param string $etag
 188  */
 189 function css_send_unmodified($lastmodified, $etag) {
 190     // 90 days only - based on Moodle point release cadence being every 3 months.
 191     $lifetime = 60 * 60 * 24 * 90;
 192     header('HTTP/1.1 304 Not Modified');
 193     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 194     header('Cache-Control: public, max-age='.$lifetime);
 195     header('Content-Type: text/css; charset=utf-8');
 196     header('Etag: "'.$etag.'"');
 197     if ($lastmodified) {
 198         header('Last-Modified: '. gmdate('D, d M Y H:i:s', $lastmodified) .' GMT');
 199     }
 200     die;
 201 }
 202
 203 /**
 204  * Sends a 404 message about CSS not being found.
 205  */
 206 function css_send_css_not_found() {
 207     header('HTTP/1.0 404 not found');
 208     die('CSS was not found, sorry.');
 209 }