lib/util.php

   1 <?php
   2 /*
   3  * Laconica - a distributed open-source microblogging tool
   4  * Copyright (C) 2008, Controlez-Vous, Inc.
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Affero General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Affero General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Affero General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* XXX: break up into separate modules (HTTP, HTML, user, files) */
  21
  22 # Show a server error
  23
  24 function common_server_error($msg, $code=500) {
  25         static $status = array(500 => 'Internal Server Error',
  26                                                    501 => 'Not Implemented',
  27                                                    502 => 'Bad Gateway',
  28                                                    503 => 'Service Unavailable',
  29                                                    504 => 'Gateway Timeout',
  30                                                    505 => 'HTTP Version Not Supported');
  31
  32         if (!array_key_exists($code, $status)) {
  33                 $code = 500;
  34         }
  35
  36         $status_string = $status[$code];
  37
  38         header('HTTP/1.1 '.$code.' '.$status_string);
  39         header('Content-type: text/plain');
  40
  41         print $msg;
  42         print "\n";
  43         exit();
  44 }
  45
  46 # Show a user error
  47 function common_user_error($msg, $code=400) {
  48         static $status = array(400 => 'Bad Request',
  49                                                    401 => 'Unauthorized',
  50                                                    402 => 'Payment Required',
  51                                                    403 => 'Forbidden',
  52                                                    404 => 'Not Found',
  53                                                    405 => 'Method Not Allowed',
  54                                                    406 => 'Not Acceptable',
  55                                                    407 => 'Proxy Authentication Required',
  56                                                    408 => 'Request Timeout',
  57                                                    409 => 'Conflict',
  58                                                    410 => 'Gone',
  59                                                    411 => 'Length Required',
  60                                                    412 => 'Precondition Failed',
  61                                                    413 => 'Request Entity Too Large',
  62                                                    414 => 'Request-URI Too Long',
  63                                                    415 => 'Unsupported Media Type',
  64                                                    416 => 'Requested Range Not Satisfiable',
  65                                                    417 => 'Expectation Failed');
  66
  67         if (!array_key_exists($code, $status)) {
  68                 $code = 400;
  69         }
  70
  71         $status_string = $status[$code];
  72
  73         header('HTTP/1.1 '.$code.' '.$status_string);
  74
  75         common_show_header('Error');
  76         common_element('div', array('class' => 'error'), $msg);
  77         common_show_footer();
  78 }
  79
  80 $xw = null;
  81
  82 # Start an HTML element
  83 function common_element_start($tag, $attrs=NULL) {
  84         global $xw;
  85         $xw->startElement($tag);
  86         if (is_array($attrs)) {
  87                 foreach ($attrs as $name => $value) {
  88                         $xw->writeAttribute($name, $value);
  89                 }
  90         } else if (is_string($attrs)) {
  91                 $xw->writeAttribute('class', $attrs);
  92         }
  93 }
  94
  95 function common_element_end($tag) {
  96         global $xw;
  97         $xw->endElement();
  98 }
  99
 100 function common_element($tag, $attrs=NULL, $content=NULL) {
 101     common_element_start($tag, $attrs);
 102         if ($content) {
 103                 global $xw;
 104                 $xw->text($content);
 105         }
 106         common_element_end($tag);
 107 }
 108
 109 function common_start_xml($doc=NULL, $public=NULL, $system=NULL) {
 110         global $xw;
 111         $xw = new XMLWriter();
 112         $xw->openURI('php://output');
 113         $xw->setIndent(true);
 114         $xw->startDocument('1.0', 'UTF-8');
 115         if ($doc) {
 116                 $xw->writeDTD($doc, $public, $system);
 117         }
 118 }
 119
 120 function common_end_xml() {
 121         global $xw;
 122         $xw->endDocument();
 123         $xw->flush();
 124 }
 125
 126 define('PAGE_TYPE_PREFS', 'application/xhtml+xml,text/html;q=0.7,application/xml;q=0.3,text/xml;q=0.2');
 127
 128 function common_show_header($pagetitle, $callable=NULL, $data=NULL, $headercall=NULL) {
 129         global $config, $xw;
 130
 131         $httpaccept = isset($_SERVER['HTTP_ACCEPT']) ? $_SERVER['HTTP_ACCEPT'] : NULL;
 132
 133         # XXX: allow content negotiation for RDF, RSS, or XRDS
 134
 135         $type = common_negotiate_type(common_accept_to_prefs($httpaccept),
 136                                                                   common_accept_to_prefs(PAGE_TYPE_PREFS));
 137
 138         if (!$type) {
 139                 common_client_error(_t('This page is not available in a media type you accept'), 406);
 140                 exit(0);
 141         }
 142
 143         header('Content-Type: '.$type);
 144
 145         common_start_xml('html',
 146                                          '-//W3C//DTD XHTML 1.0 Strict//EN',
 147                                          'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd');
 148
 149         # FIXME: correct language for interface
 150
 151         common_element_start('html', array('xmlns' => 'http://www.w3.org/1999/xhtml',
 152                                                                            'xml:lang' => 'en',
 153                                                                            'lang' => 'en'));
 154
 155         common_element_start('head');
 156         common_element('title', NULL,
 157                                    $pagetitle . " - " . $config['site']['name']);
 158         common_element('link', array('rel' => 'stylesheet',
 159                                                                  'type' => 'text/css',
 160                                                                  'href' => theme_path('display.css'),
 161                                                                  'media' => 'screen, projection, tv'));
 162         foreach (array(6,7) as $ver) {
 163                 if (file_exists(theme_file('ie'.$ver.'.css'))) {
 164                         # Yes, IE people should be put in jail.
 165                         $xw->writeComment('[if lte IE '.$ver.']><link rel="stylesheet" type="text/css" '.
 166                                                           'href="'.theme_path('ie'.$ver.'.css').' /><![endif]');
 167                 }
 168         }
 169
 170         common_element('script', array('type' => 'text/javascript',
 171                                                                    'src' => common_path('js/jquery.min.js')),
 172                                    ' ');
 173
 174         if ($callable) {
 175                 if ($data) {
 176                         call_user_func($callable, $data);
 177                 } else {
 178                         call_user_func($callable);
 179                 }
 180         }
 181         common_element_end('head');
 182         common_element_start('body');
 183         common_element_start('div', array('id' => 'wrap'));
 184         common_element_start('div', array('id' => 'header'));
 185         common_nav_menu();
 186         if ($config['site']['logo'] || file_exists(theme_file('logo.png'))) {
 187                 common_element_start('a', array('href' => common_local_url('public')));
 188                 common_element('img', array('src' => ($config['site']['logo']) ?
 189                                                                         ($config['site']['logo']) : theme_path('logo.png'),
 190                                                                         'alt' => $config['site']['name'],
 191                                                                         'id' => 'logo'));
 192                 common_element_end('a');
 193         } else {
 194                 common_element('p', 'branding', $config['site']['name']);
 195         }
 196
 197         common_element('h1', 'pagetitle', $pagetitle);
 198
 199         if ($headercall) {
 200                 if ($data) {
 201                         call_user_func($headercall, $data);
 202                 } else {
 203                         call_user_func($headercall);
 204                 }
 205         }
 206         common_element_end('div');
 207         common_element_start('div', array('id' => 'content'));
 208 }
 209
 210 function common_show_footer() {
 211         global $xw, $config;
 212         common_element_end('div'); # content div
 213         common_foot_menu();
 214         common_element_start('div', array('id' => 'footer'));
 215         common_element_start('p', 'laconica');
 216         common_text(_t('This site is running the '));
 217         common_element('a', array('class' => 'software',
 218                                                           href => 'http://laconi.ca/'),
 219                                    'Laconica');
 220         common_text(_t('microblogging tool, version ' . LACONICA_VERSION . ', available under the '));
 221         common_element('a', array(href => 'http://www.fsf.org/licensing/licenses/agpl-3.0.html'),
 222                                    'GNU Affero General Public License');
 223         common_text(_t('.'));
 224         common_element_end('p');
 225         common_element('img', array('id' => 'cc',
 226                                                                 'src' => $config['license']['image'],
 227                                                                 'alt' => $config['license']['title']));
 228         common_element_start('p');
 229         common_text(_t('Unless otherwise specified, contents of this site are copyright by the contributors and available under the '));
 230         common_element('a', array('class' => 'license',
 231                                                           'rel' => 'license',
 232                                                           href => $config['license']['url']),
 233                                    $config['license']['title']);
 234         common_text(_t('. Contributors should be attributed by full name or nickname.'));
 235         common_element_end('p');
 236         common_element_end('div');
 237         common_element_end('div');
 238         common_element_end('body');
 239         common_element_end('html');
 240         common_end_xml();
 241 }
 242
 243 function common_text($txt) {
 244         global $xw;
 245         $xw->text($txt);
 246 }
 247
 248 function common_raw($xml) {
 249         global $xw;
 250         $xw->writeRaw($xml);
 251 }
 252
 253 function common_nav_menu() {
 254         $user = common_current_user();
 255         common_element_start('ul', array('id' => 'nav'));
 256         if ($user) {
 257                 common_menu_item(common_local_url('all', array('nickname' => $user->nickname)),
 258                                                  _t('Home'));
 259         }
 260         common_menu_item(common_local_url('public'), _t('Public'));
 261         common_menu_item(common_local_url('doc', array('title' => 'help')),
 262                                          _t('Help'));
 263         if ($user) {
 264                 common_menu_item(common_local_url('profilesettings'),
 265                                                  _t('Settings'));
 266                 common_menu_item(common_local_url('logout'),
 267                                                  _t('Logout'));
 268         } else {
 269                 common_menu_item(common_local_url('login'), _t('Login'));
 270                 common_menu_item(common_local_url('register'), _t('Register'));
 271                 common_menu_item(common_local_url('openidlogin'), _t('OpenID'));
 272         }
 273         common_element_end('ul');
 274 }
 275
 276 function common_foot_menu() {
 277         common_element_start('ul', array('id' => 'nav_sub'));
 278         common_menu_item(common_local_url('doc', array('title' => 'about')),
 279                                          _t('About'));
 280         common_menu_item(common_local_url('doc', array('title' => 'privacy')),
 281                                          _t('Privacy'));
 282         common_menu_item(common_local_url('doc', array('title' => 'source')),
 283                                          _t('Source'));
 284         common_element_end('ul');
 285 }
 286
 287 function common_menu_item($url, $text, $title=NULL, $is_selected=false) {
 288         $lattrs = array();
 289         if ($is_selected) {
 290                 $lattrs['class'] = 'current';
 291         }
 292         common_element_start('li', $lattrs);
 293         $attrs['href'] = $url;
 294         if ($title) {
 295                 $attrs['title'] = $title;
 296         }
 297         common_element('a', $attrs, $text);
 298         common_element_end('li');
 299 }
 300
 301 function common_input($id, $label, $value=NULL,$instructions=NULL) {
 302         common_element_start('p');
 303         common_element('label', array('for' => $id), $label);
 304         $attrs = array('name' => $id,
 305                                    'type' => 'text',
 306                                    'id' => $id);
 307         if ($value) {
 308                 $attrs['value'] = htmlspecialchars($value);
 309         }
 310         common_element('input', $attrs);
 311         if ($instructions) {
 312                 common_element('span', 'input_instructions', $instructions);
 313         }
 314         common_element_end('p');
 315 }
 316
 317 function common_hidden($id, $value) {
 318         common_element('input', array('name' => $id,
 319                                                                   'type' => 'hidden',
 320                                                                   'id' => $id,
 321                                                                   'value' => $value));
 322 }
 323
 324 function common_password($id, $label, $instructions=NULL) {
 325         common_element_start('p');
 326         common_element('label', array('for' => $id), $label);
 327         $attrs = array('name' => $id,
 328                                    'type' => 'password',
 329                                    'id' => $id);
 330         common_element('input', $attrs);
 331         if ($instructions) {
 332                 common_element('span', 'input_instructions', $instructions);
 333         }
 334         common_element_end('p');
 335 }
 336
 337 function common_submit($id, $label) {
 338         global $xw;
 339         common_element_start('p');
 340         common_element('input', array('type' => 'submit',
 341                                                                   'id' => $id,
 342                                                                   'name' => $id,
 343                                                                   'class' => 'submit',
 344                                                                   'value' => $label));
 345         common_element_end('p');
 346 }
 347
 348 function common_textarea($id, $label, $content=NULL, $instructions=NULL) {
 349         common_element_start('p');
 350         common_element('label', array('for' => $id), $label);
 351         common_element('textarea', array('rows' => 3,
 352                                                                          'cols' => 40,
 353                                                                          'name' => $id,
 354                                                                          'id' => $id),
 355                                    ($content) ? $content : ' ');
 356         if ($instructions) {
 357                 common_element('span', 'input_instructions', $instructions);
 358         }
 359         common_element_end('p');
 360 }
 361
 362 # salted, hashed passwords are stored in the DB
 363
 364 function common_munge_password($id, $password) {
 365         return md5($id . $password);
 366 }
 367
 368 # check if a username exists and has matching password
 369 function common_check_user($nickname, $password) {
 370         $user = User::staticGet('nickname', $nickname);
 371         if (is_null($user)) {
 372                 return false;
 373         } else {
 374                 return (0 == strcmp(common_munge_password($password, $user->id),
 375                                                         $user->password));
 376         }
 377 }
 378
 379 # is the current user logged in?
 380 function common_logged_in() {
 381         return (!is_null(common_current_user()));
 382 }
 383
 384 function common_have_session() {
 385         return (0 != strcmp(session_id(), ''));
 386 }
 387
 388 function common_ensure_session() {
 389         if (!common_have_session()) {
 390                 @session_start();
 391         }
 392 }
 393
 394 function common_set_user($nickname) {
 395         if (is_null($nickname) && common_have_session()) {
 396                 unset($_SESSION['userid']);
 397                 return true;
 398         } else {
 399                 $user = User::staticGet('nickname', $nickname);
 400                 if ($user) {
 401                         common_ensure_session();
 402                         $_SESSION['userid'] = $user->id;
 403                         return true;
 404                 } else {
 405                         return false;
 406                 }
 407         }
 408         return false;
 409 }
 410
 411 # who is the current user?
 412 function common_current_user() {
 413         static $user = NULL; # FIXME: global memcached
 414         if (is_null($user)) {
 415                 common_ensure_session();
 416                 $id = $_SESSION['userid'];
 417                 if ($id) {
 418                         $user = User::staticGet($id);
 419                 }
 420         }
 421         return $user;
 422 }
 423
 424 # get canonical version of nickname for comparison
 425 function common_canonical_nickname($nickname) {
 426         # XXX: UTF-8 canonicalization (like combining chars)
 427         return strtolower($nickname);
 428 }
 429
 430 # get canonical version of email for comparison
 431 function common_canonical_email($email) {
 432         # XXX: canonicalize UTF-8
 433         # XXX: lcase the domain part
 434         return $email;
 435 }
 436
 437 define('URL_REGEX', '^|[ \t\r\n])((ftp|http|https|gopher|mailto|news|nntp|telnet|wais|file|prospero|aim|webcal):(([A-Za-z0-9$_.+!*(),;/?:@&~=-])|%[A-Fa-f0-9]{2}){2,}(#([a-zA-Z0-9][a-zA-Z0-9$_.+!*(),;/?:@&~=%-]*))?([A-Za-z0-9$_+!*();/?:~-]))');
 438
 439 function common_render_content($text, $notice) {
 440         $r = htmlspecialchars($text);
 441         $id = $notice->profile_id;
 442         $r = preg_replace('@https?://\S+@', '<a href="\0" class="extlink">\0</a>', $r);
 443         $r = preg_replace('/(^|\b)@([\w-]+)($|\b)/e', "'\\1@'.common_at_link($id, '\\2').'\\3'", $r);
 444         # XXX: # tags
 445         # XXX: machine tags
 446         return $r;
 447 }
 448
 449 function common_at_link($sender_id, $nickname) {
 450         # Try to find profiles this profile is subscribed to that have this nickname
 451         $recipient = new Profile();
 452         # XXX: chokety and bad
 453         $recipient->whereAdd('EXISTS (SELECT subscribed from subscription where subscriber = '.$sender_id.' and subscribed = id)', 'AND');
 454         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 455         if ($recipient->find(TRUE)) {
 456                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistenee">'.$nickname.'</a>';
 457         }
 458         # Try to find profiles that listen to this profile and that have this nickname
 459         $recipient = new Profile();
 460         # XXX: chokety and bad
 461         $recipient->whereAdd('EXISTS (SELECT subscriber from subscription where subscribed = '.$sender_id.' and subscriber = id)', 'AND');
 462         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 463         if ($recipient->find(TRUE)) {
 464                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistener">'.$nickname.'</a>';
 465         }
 466         # If this is a local user, try to find a local user with that nickname.
 467         $sender = User::staticGet($sender_id);
 468         if ($sender) {
 469                 $recipient_user = User::staticGet('nickname', $nickname);
 470                 if ($recipient_user) {
 471                         $recipient = $recipient->getProfile();
 472                         return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink usertouser">'.$nickname.'</a>';
 473                 }
 474         }
 475         # Otherwise, no links. @messages from local users to remote users,
 476         # or from remote users to other remote users, are just
 477         # outside our ability to make intelligent guesses about
 478         return $nickname;
 479 }
 480
 481 // where should the avatar go for this user?
 482
 483 function common_avatar_filename($id, $extension, $size=NULL, $extra=NULL) {
 484         global $config;
 485
 486         if ($size) {
 487                 return $id . '-' . $size . (($extra) ? ('-' . $extra) : '') . $extension;
 488         } else {
 489                 return $id . '-original' . (($extra) ? ('-' . $extra) : '') . $extension;
 490         }
 491 }
 492
 493 function common_avatar_path($filename) {
 494         global $config;
 495         return INSTALLDIR . '/avatar/' . $filename;
 496 }
 497
 498 function common_avatar_url($filename) {
 499         return common_path('avatar/'.$filename);
 500 }
 501
 502 function common_default_avatar($size) {
 503         static $sizenames = array(AVATAR_PROFILE_SIZE => 'profile',
 504                                                           AVATAR_STREAM_SIZE => 'stream',
 505                                                           AVATAR_MINI_SIZE => 'mini');
 506         return theme_path('default-avatar-'.$sizenames[$size].'.png');
 507 }
 508
 509 function common_local_url($action, $args=NULL) {
 510         global $config;
 511         if ($config['site']['fancy']) {
 512                 return common_fancy_url($action, $args);
 513         } else {
 514                 return common_simple_url($action, $args);
 515         }
 516 }
 517
 518 function common_fancy_url($action, $args=NULL) {
 519         switch (strtolower($action)) {
 520          case 'public':
 521                 if ($args && $args['page']) {
 522                         return common_path('?page=' . $args['page']);
 523                 } else {
 524                         return common_path('');
 525                 }
 526          case 'publicrss':
 527                 return common_path('rss');
 528          case 'doc':
 529                 return common_path('doc/'.$args['title']);
 530          case 'login':
 531          case 'logout':
 532          case 'register':
 533          case 'subscribe':
 534          case 'unsubscribe':
 535                 return common_path('main/'.$action);
 536          case 'openidlogin':
 537                 return common_path('main/openid');
 538          case 'avatar':
 539          case 'password':
 540                 return common_path('settings/'.$action);
 541          case 'profilesettings':
 542                 return common_path('settings/profile');
 543          case 'openidsettings':
 544                 return common_path('settings/openid');
 545          case 'newnotice':
 546                 return common_path('notice/new');
 547          case 'shownotice':
 548                 return common_path('notice/'.$args['notice']);
 549          case 'xrds':
 550          case 'foaf':
 551                 return common_path($args['nickname'].'/'.$action);
 552          case 'subscriptions':
 553          case 'subscribed':
 554          case 'all':
 555                 if ($args && $args['page']) {
 556                         return common_path($args['nickname'].'/'.$action.'?page=' . $args['page']);
 557                 } else {
 558                         return common_path($args['nickname'].'/'.$action);
 559                 }
 560          case 'allrss':
 561                 return common_path($args['nickname'].'/all/rss');
 562          case 'userrss':
 563                 return common_path($args['nickname'].'/rss');
 564          case 'showstream':
 565                 if ($args && $args['page']) {
 566                         return common_path($args['nickname'].'?page=' . $args['page']);
 567                 } else {
 568                         return common_path($args['nickname']);
 569                 }
 570          default:
 571                 return common_simple_url($action, $args);
 572         }
 573 }
 574
 575 function common_simple_url($action, $args=NULL) {
 576         global $config;
 577         /* XXX: pretty URLs */
 578         $extra = '';
 579         if ($args) {
 580                 foreach ($args as $key => $value) {
 581                         $extra .= "&${key}=${value}";
 582                 }
 583         }
 584         return common_path("index.php?action=${action}${extra}");
 585 }
 586
 587 function common_path($relative) {
 588         global $config;
 589         $pathpart = ($config['site']['path']) ? $config['site']['path']."/" : '';
 590         return "http://".$config['site']['server'].'/'.$pathpart.$relative;
 591 }
 592
 593 function common_date_string($dt) {
 594         // XXX: do some sexy date formatting
 595         // return date(DATE_RFC822, $dt);
 596         return $dt;
 597 }
 598
 599 function common_date_w3dtf($dt) {
 600         $t = strtotime($dt);
 601         return date(DATE_W3C, $t);
 602 }
 603
 604 function common_redirect($url, $code=307) {
 605         static $status = array(301 => "Moved Permanently",
 606                                                    302 => "Found",
 607                                                    303 => "See Other",
 608                                                    307 => "Temporary Redirect");
 609         header("Status: ${code} $status[$code]");
 610         header("Location: $url");
 611         common_element('a', array('href' => $url), $url);
 612 }
 613
 614 function common_broadcast_notice($notice, $remote=false) {
 615         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 616         if (!$remote) {
 617                 # Make sure we have the OMB stuff
 618                 require_once(INSTALLDIR.'/lib/omb.php');
 619                 omb_broadcast_remote_subscribers($notice);
 620         }
 621         // XXX: broadcast notices to Jabber
 622         // XXX: broadcast notices to SMS
 623         // XXX: broadcast notices to other IM
 624         return true;
 625 }
 626
 627 function common_broadcast_profile($profile) {
 628         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 629         require_once(INSTALLDIR.'/lib/omb.php');
 630         omb_broadcast_profile($profile);
 631         // XXX: Other broadcasts...?
 632         return true;
 633 }
 634
 635 function common_profile_url($nickname) {
 636         return common_local_url('showstream', array('nickname' => $nickname));
 637 }
 638
 639 # Don't call if nobody's logged in
 640
 641 function common_notice_form() {
 642         $user = common_current_user();
 643         assert(!is_null($user));
 644         common_element_start('form', array('id' => 'status_form',
 645                                                                            'method' => 'POST',
 646                                                                            'action' => common_local_url('newnotice')));
 647         common_element_start('p');
 648         common_element('label', array('for' => 'status_update',
 649                                                                   'id' => 'status_label'),
 650                                    _t('What\'s up, ').$user->nickname.'?');
 651         common_element('textarea', array('id' => 'status_textarea',
 652                                                                          'name' => 'status_textarea'),
 653                                    ' ');
 654         common_element('input', array('id' => 'status_submit',
 655                                                                   'name' => 'status_submit',
 656                                                                   'type' => 'submit',
 657                                                                   'value' => _t('Send')));
 658         common_element_end('p');
 659         common_element_end('form');
 660 }
 661
 662 function common_mint_tag($extra) {
 663         global $config;
 664         return
 665           'tag:'.$config['tag']['authority'].','.
 666           $config['tag']['date'].':'.$config['tag']['prefix'].$extra;
 667 }
 668
 669 # Should make up a reasonable root URL
 670
 671 function common_root_url() {
 672         return common_path('');
 673 }
 674
 675 # returns $bytes bytes of random data as a hexadecimal string
 676 # "good" here is a goal and not a guarantee
 677
 678 function common_good_rand($bytes) {
 679         # XXX: use random.org...?
 680         if (file_exists('/dev/urandom')) {
 681                 return common_urandom($bytes);
 682         } else { # FIXME: this is probably not good enough
 683                 return common_mtrand($bytes);
 684         }
 685 }
 686
 687 function common_urandom($bytes) {
 688         $h = fopen('/dev/urandom', 'rb');
 689         # should not block
 690         $src = fread($h, $bytes);
 691         fclose($h);
 692         $enc = '';
 693         for ($i = 0; $i < $bytes; $i++) {
 694                 $enc .= sprintf("%02x", (ord($src[$i])));
 695         }
 696         return $enc;
 697 }
 698
 699 function common_mtrand($bytes) {
 700         $enc = '';
 701         for ($i = 0; $i < $bytes; $i++) {
 702                 $enc .= sprintf("%02x", mt_rand(0, 255));
 703         }
 704         return $enc;
 705 }
 706
 707 function common_set_returnto($url) {
 708         common_ensure_session();
 709         $_SESSION['returnto'] = $url;
 710 }
 711
 712 function common_get_returnto() {
 713         common_ensure_session();
 714         return $_SESSION['returnto'];
 715 }
 716
 717 function common_timestamp() {
 718         return date('YmdHis');
 719 }
 720
 721 // XXX: set up gettext
 722
 723 function _t($str) {
 724         return $str;
 725 }
 726
 727 function common_ensure_syslog() {
 728         static $initialized = false;
 729         if (!$initialized) {
 730                 global $config;
 731                 define_syslog_variables();
 732                 openlog($config['syslog']['appname'], 0, LOG_USER);
 733                 $initialized = true;
 734         }
 735 }
 736
 737 function common_log($priority, $msg, $filename=NULL) {
 738         common_ensure_syslog();
 739         syslog($priority, $msg);
 740 }
 741
 742 function common_debug($msg, $filename=NULL) {
 743         if ($filename) {
 744                 common_log(LOG_DEBUG, basename($filename).' - '.$msg);
 745         } else {
 746                 common_log(LOG_DEBUG, $msg);
 747         }
 748 }
 749
 750 function common_valid_http_url($url) {
 751         return Validate::uri($url, array('allowed_schemes' => array('http', 'https')));
 752 }
 753
 754 function common_valid_tag($tag) {
 755         if (preg_match('/^tag:(.*?),(\d{4}(-\d{2}(-\d{2})?)?):(.*)$/', $tag, $matches)) {
 756                 return (Validate::email($matches[1]) ||
 757                                 preg_match('/^([\w-\.]+)$/', $matches[1]));
 758         }
 759         return false;
 760 }
 761
 762 # Does a little before-after block for next/prev page
 763
 764 function common_pagination($have_before, $have_after, $page, $action, $args=NULL) {
 765
 766         if ($have_before || $have_after) {
 767                 common_element_start('div', array('id' => 'pagination'));
 768                 common_element_start('ul', array('id' => 'nav_pagination'));
 769         }
 770
 771         if ($have_before) {
 772                 $pargs = array('page' => $page-1);
 773                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 774
 775                 common_element_start('li', 'before');
 776                 common_element('a', array('href' => common_local_url($action, $newargs)),
 777                                            _t('« After'));
 778                 common_element_end('li');
 779         }
 780
 781         if ($have_after) {
 782                 $pargs = array('page' => $page+1);
 783                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 784                 common_element_start('li', 'after');
 785                 common_element('a', array('href' => common_local_url($action, $newargs)),
 786                                                    _t('Before »'));
 787                 common_element_end('li');
 788         }
 789
 790         if ($have_before || $have_after) {
 791                 common_element_end('ul');
 792                 common_element_end('div');
 793         }
 794 }
 795
 796 /* Following functions are copied from MediaWiki GlobalFunctions.php
 797  * and written by Evan Prodromou. */
 798
 799 function common_accept_to_prefs($accept, $def = '*/*') {
 800         # No arg means accept anything (per HTTP spec)
 801         if(!$accept) {
 802                 return array($def => 1);
 803         }
 804
 805         $prefs = array();
 806
 807         $parts = explode(',', $accept);
 808
 809         foreach($parts as $part) {
 810                 # FIXME: doesn't deal with params like 'text/html; level=1'
 811                 @list($value, $qpart) = explode(';', $part);
 812                 $match = array();
 813                 if(!isset($qpart)) {
 814                         $prefs[$value] = 1;
 815                 } elseif(preg_match('/q\s*=\s*(\d*\.\d+)/', $qpart, $match)) {
 816                         $prefs[$value] = $match[1];
 817                 }
 818         }
 819
 820         return $prefs;
 821 }
 822
 823 function common_mime_type_match($type, $avail) {
 824         if(array_key_exists($type, $avail)) {
 825                 return $type;
 826         } else {
 827                 $parts = explode('/', $type);
 828                 if(array_key_exists($parts[0] . '/*', $avail)) {
 829                         return $parts[0] . '/*';
 830                 } elseif(array_key_exists('*/*', $avail)) {
 831                         return '*/*';
 832                 } else {
 833                         return NULL;
 834                 }
 835         }
 836 }
 837
 838 function common_negotiate_type($cprefs, $sprefs) {
 839         $combine = array();
 840
 841         foreach(array_keys($sprefs) as $type) {
 842                 $parts = explode('/', $type);
 843                 if($parts[1] != '*') {
 844                         $ckey = common_mime_type_match($type, $cprefs);
 845                         if($ckey) {
 846                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
 847                         }
 848                 }
 849         }
 850
 851         foreach(array_keys($cprefs) as $type) {
 852                 $parts = explode('/', $type);
 853                 if($parts[1] != '*' && !array_key_exists($type, $sprefs)) {
 854                         $skey = common_mime_type_match($type, $sprefs);
 855                         if($skey) {
 856                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
 857                         }
 858                 }
 859         }
 860
 861         $bestq = 0;
 862         $besttype = NULL;
 863
 864         foreach(array_keys($combine) as $type) {
 865                 if($combine[$type] > $bestq) {
 866                         $besttype = $type;
 867                         $bestq = $combine[$type];
 868                 }
 869         }
 870
 871         return $besttype;
 872 }
 873
 874 function common_config($main, $sub) {
 875         global $config;
 876         return $config[$main][$sub];
 877 }