theme/styles.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 is responsible for serving the one huge CSS of each theme.
  19  *
  20  * @package   core
  21  * @copyright 2009 Petr Skoda (skodak)  {@link http://skodak.org}
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 // Disable moodle specific debug messages and any errors in output,
  26 // comment out when debugging or better look into error log!
  27 define('NO_DEBUG_DISPLAY', true);
  28
  29 define('ABORT_AFTER_CONFIG', true);
  30 require('../config.php');
  31 require_once($CFG->dirroot.'/lib/csslib.php');
  32
  33 if ($slashargument = min_get_slash_argument()) {
  34     $slashargument = ltrim($slashargument, '/');
  35     if (substr_count($slashargument, '/') < 2) {
  36         css_send_css_not_found();
  37     }
  38
  39     if (strpos($slashargument, '_s/') === 0) {
  40         // Can't use SVG.
  41         $slashargument = substr($slashargument, 3);
  42         $usesvg = false;
  43     } else {
  44         $usesvg = true;
  45     }
  46
  47     $chunk = null;
  48     if (preg_match('#/(chunk(\d+)(/|$))#', $slashargument, $matches)) {
  49         $chunk = (int)$matches[2];
  50         $slashargument = str_replace($matches[1], '', $slashargument);
  51     }
  52
  53     list($themename, $rev, $type) = explode('/', $slashargument, 3);
  54     $themename = min_clean_param($themename, 'SAFEDIR');
  55     $rev       = min_clean_param($rev, 'RAW');
  56     $type      = min_clean_param($type, 'SAFEDIR');
  57
  58 } else {
  59     $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
  60     $rev       = min_optional_param('rev', 0, 'RAW');
  61     $type      = min_optional_param('type', 'all', 'SAFEDIR');
  62     $chunk     = min_optional_param('chunk', null, 'INT');
  63     $usesvg    = (bool)min_optional_param('svg', '1', 'INT');
  64 }
  65
  66 // Check if we received a theme sub revision which allows us
  67 // to handle local caching on a per theme basis.
  68 $values = explode('_', $rev);
  69 $rev = min_clean_param(array_shift($values), 'INT');
  70 $themesubrev = array_shift($values);
  71
  72 if (!is_null($themesubrev)) {
  73     $themesubrev = min_clean_param($themesubrev, 'INT');
  74 }
  75
  76 // Check that type fits into the expected values.
  77 if ($type === 'editor') {
  78     // The editor CSS is never chunked.
  79     $chunk = null;
  80 } else if ($type === 'all' || $type === 'all-rtl') {
  81     // We're fine.
  82 } else {
  83     css_send_css_not_found();
  84 }
  85
  86 if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
  87     // The theme exists in standard location - ok.
  88 } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
  89     // Alternative theme location contains this theme - ok.
  90 } else {
  91     header('HTTP/1.0 404 not found');
  92     die('Theme was not found, sorry.');
  93 }
  94
  95 $candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";
  96 $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);
  97 $chunkedcandidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg, $chunk);
  98 $etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg, $chunk);
  99
 100 if (file_exists($chunkedcandidatesheet)) {
 101     if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
 102         // We do not actually need to verify the etag value because our files
 103         // never change in cache because we increment the rev counter.
 104         css_send_unmodified(filemtime($chunkedcandidatesheet), $etag);
 105     }
 106     css_send_cached_css($chunkedcandidatesheet, $etag);
 107 }
 108
 109 // Ok, now we need to start normal moodle script, we need to load all libs and $DB.
 110 define('ABORT_AFTER_CONFIG_CANCEL', true);
 111
 112 define('NO_MOODLE_COOKIES', true); // Session not used here.
 113 define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check.
 114
 115 require("$CFG->dirroot/lib/setup.php");
 116
 117 $theme = theme_config::load($themename);
 118 $theme->force_svg_use($usesvg);
 119 $theme->set_rtl_mode($type === 'all-rtl' ? true : false);
 120
 121 $themerev = theme_get_revision();
 122 $currentthemesubrev = theme_get_sub_revision_for_theme($themename);
 123
 124 $cache = true;
 125 // If the client is requesting a revision that doesn't match both
 126 // the global theme revision and the theme specific revision then
 127 // tell the browser not to cache this style sheet because it's
 128 // likely being regenerated.
 129 if ($themerev <= 0 or $themerev != $rev or $themesubrev != $currentthemesubrev) {
 130     $rev = $themerev;
 131     $themesubrev = $currentthemesubrev;
 132     $cache = false;
 133
 134     $candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";
 135     $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);
 136     $chunkedcandidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg, $chunk);
 137     $etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg, $chunk);
 138 }
 139
 140 make_localcache_directory('theme', false);
 141
 142 if ($type === 'editor') {
 143     $csscontent = $theme->get_css_content_editor();
 144
 145     if ($cache) {
 146         css_store_css($theme, $candidatesheet, $csscontent, false);
 147         css_send_cached_css($candidatesheet, $etag);
 148     } else {
 149         css_send_uncached_css($csscontent);
 150     }
 151
 152 }
 153
 154 if (($fallbacksheet = theme_styles_fallback_content($theme)) && !$theme->has_css_cached_content()) {
 155     // The theme is not yet available and a fallback is available.
 156     // Return the fallback immediately, specifying the Content-Length, then generate in the background.
 157     $css = file_get_contents($fallbacksheet);
 158     css_send_temporary_css($css);
 159
 160     // The fallback content has now been sent.
 161     // There will be an attempt to generate the content, but it should not be served.
 162     // The Content-Length above means that the client will disregard it anyway.
 163     $sendaftergeneration = false;
 164
 165     // There may be another client currently holding a lock and generating the stylesheet.
 166     // Use a very low lock timeout as the connection will be ended immediately afterwards.
 167     $locktimeout = 1;
 168 } else {
 169     // There is no fallback content to be issued here, therefore the generated content must be output.
 170     $sendaftergeneration = true;
 171
 172     // Use a realistic lock timeout as the intention is to avoid lock contention.
 173     $locktimeout = rand(90, 120);
 174 }
 175
 176 // Attempt to fetch the lock.
 177 $lockfactory = \core\lock\lock_config::get_lock_factory('core_theme_get_css_content');
 178 $lock = $lockfactory->get_lock($themename, $locktimeout);
 179
 180 if ($sendaftergeneration || $lock) {
 181     // Either the lock was successful, or the lock was unsuccessful but the content *must* be sent.
 182     if (!file_exists($chunkedcandidatesheet)) {
 183         // The content does not exist locally.
 184         // Generate and save it.
 185         $candidatesheet = theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir);
 186     }
 187
 188     if ($lock) {
 189         $lock->release();
 190     }
 191
 192     if ($sendaftergeneration) {
 193         if (!$cache) {
 194             // Do not pollute browser caches if invalid revision requested,
 195             // let's ignore legacy IE breakage here too.
 196             css_send_uncached_css(file_get_contents($candidatesheet));
 197
 198         } else if ($chunk !== null and file_exists($chunkedcandidatesheet)) {
 199             // Greetings stupid legacy IEs!
 200             css_send_cached_css($chunkedcandidatesheet, $etag);
 201
 202         } else {
 203             // Real browsers - this is the expected result!
 204             css_send_cached_css($candidatesheet, $etag);
 205         }
 206     }
 207 }
 208
 209 /**
 210  * Generate the theme CSS and store it.
 211  *
 212  * @param   theme_config    $theme The theme to be generated
 213  * @param   int             $rev The theme revision
 214  * @param   int             $themesubrev The theme sub-revision
 215  * @param   string          $candidatedir The directory that it should be stored in
 216  * @return  string          The path that the primary (non-chunked) CSS was written to
 217  */
 218 function theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir) {
 219     global $CFG;
 220     require_once("{$CFG->libdir}/filelib.php");
 221
 222     // Generate the content first.
 223     if (!$csscontent = $theme->get_css_cached_content()) {
 224         $csscontent = $theme->get_css_content();
 225         $theme->set_css_content_cache($csscontent);
 226     }
 227
 228     if ($theme->get_rtl_mode()) {
 229         $type = "all-rtl";
 230     } else {
 231         $type = "all";
 232     }
 233
 234     // Determine the candidatesheet path.
 235     // Note: Do not pass any value for chunking as this is calcualted during css storage.
 236     $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $theme->use_svg_icons());
 237
 238     // Determine the chunking URL.
 239     // Note, this will be removed when support for IE9 is removed.
 240     $relroot = preg_replace('|^http.?://[^/]+|', '', $CFG->wwwroot);
 241     if (!empty(min_get_slash_argument())) {
 242         if ($theme->use_svg_icons()) {
 243             $chunkurl = "{$relroot}/theme/styles.php/{$theme->name}/{$rev}/$type";
 244         } else {
 245             $chunkurl = "{$relroot}/theme/styles.php/_s/{$theme->name}/{$rev}/$type";
 246         }
 247     } else {
 248         if ($theme->use_svg_icons()) {
 249             $chunkurl = "{$relroot}/theme/styles.php?theme={$theme->name}&rev={$rev}&type=$type";
 250         } else {
 251             $chunkurl = "{$relroot}/theme/styles.php?theme={$theme->name}&rev={$rev}&type=$type&svg=0";
 252         }
 253     }
 254
 255     // Store the CSS.
 256     css_store_css($theme, $candidatesheet, $csscontent, true, $chunkurl);
 257
 258     // Store the fallback CSS in the temp directory.
 259     // This file is used as a fallback when waiting for a theme to compile and is not versioned in any way.
 260     $fallbacksheet = make_temp_directory("theme/{$theme->name}")
 261         . "/"
 262         . theme_styles_get_filename($type, 0, $theme->use_svg_icons());
 263     css_store_css($theme, $fallbacksheet, $csscontent, true, $chunkurl);
 264
 265     // Delete older revisions from localcache.
 266     $themecachedirs = glob("{$CFG->localcachedir}/theme/*", GLOB_ONLYDIR);
 267     foreach ($themecachedirs as $localcachedir) {
 268         $cachedrev = [];
 269         preg_match("/\/theme\/([0-9]+)$/", $localcachedir, $cachedrev);
 270         $cachedrev = isset($cachedrev[1]) ? intval($cachedrev[1]) : 0;
 271         if ($cachedrev > 0 && $cachedrev < $rev) {
 272             fulldelete($localcachedir);
 273         }
 274     }
 275
 276     // Delete older theme subrevision CSS from localcache.
 277     $subrevfiles = glob("{$CFG->localcachedir}/theme/{$rev}/{$theme->name}/css/*.css");
 278     foreach ($subrevfiles as $subrevfile) {
 279         $cachedsubrev = [];
 280         preg_match("/_([0-9]+)\.([0-9]+\.)?css$/", $subrevfile, $cachedsubrev);
 281         $cachedsubrev = isset($cachedsubrev[1]) ? intval($cachedsubrev[1]) : 0;
 282         if ($cachedsubrev > 0 && $cachedsubrev < $themesubrev) {
 283             fulldelete($subrevfile);
 284         }
 285     }
 286
 287     return $candidatesheet;
 288 }
 289
 290 /**
 291  * Fetch the preferred fallback content location if available.
 292  *
 293  * @param   theme_config    $theme The theme to be generated
 294  * @return  string          The path to the fallback sheet on disk
 295  */
 296 function theme_styles_fallback_content($theme) {
 297     global $CFG;
 298
 299     if (!$theme->usefallback) {
 300         // This theme does not support fallbacks.
 301         return false;
 302     }
 303
 304     $type = $theme->get_rtl_mode() ? 'all-rtl' : 'all';
 305     $filename = theme_styles_get_filename($type);
 306
 307     $fallbacksheet = "{$CFG->tempdir}/theme/{$theme->name}/{$filename}";
 308     if (file_exists($fallbacksheet)) {
 309         return $fallbacksheet;
 310     }
 311
 312     return false;
 313 }
 314
 315 /**
 316  * Get the filename for the specified configuration.
 317  *
 318  * @param   string  $type The requested sheet type
 319  * @param   int     $themesubrev The theme sub-revision
 320  * @param   bool    $usesvg Whether SVGs are allowed
 321  * @param   int     $chunk The chunk number if specified
 322  * @return  string  The filename for this sheet
 323  */
 324 function theme_styles_get_filename($type, $themesubrev = 0, $usesvg = true, $chunk = null) {
 325     $filename = $type;
 326     $filename .= ($themesubrev > 0) ? "_{$themesubrev}" : '';
 327     $filename .= $usesvg ? '' : '-nosvg';
 328     $filename .= $chunk ? ".{$chunk}" : '';
 329
 330     return "{$filename}.css";
 331 }
 332
 333 /**
 334  * Determine the correct etag for the specified configuration.
 335  *
 336  * @param   string  $themename The name of the theme
 337  * @param   int     $rev The revision number
 338  * @param   string  $type The requested sheet type
 339  * @param   int     $themesubrev The theme sub-revision
 340  * @param   bool    $usesvg Whether SVGs are allowed
 341  * @param   int     $chunk The chunk number if specified
 342  * @return  string  The etag to use for this request
 343  */
 344 function theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg, $chunk) {
 345     $etag = [$rev, $themename, $type, $themesubrev];
 346
 347     if (!$usesvg) {
 348         $etag[] = 'nosvg';
 349     }
 350
 351     if ($chunk) {
 352         $etag[] = "chunk{$chunk}";
 353     }
 354
 355     return sha1(implode('/', $etag));
 356 }