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 ((is_string($config['site']['logo']) && (strlen($config['site']['logo']) > 0))
 187                 || file_exists(theme_file('logo.png')))
 188         {
 189                 common_element_start('a', array('href' => common_local_url('public')));
 190                 common_element('img', array('src' => ($config['site']['logo']) ?
 191                                                                         ($config['site']['logo']) : theme_path('logo.png'),
 192                                                                         'alt' => $config['site']['name'],
 193                                                                         'id' => 'logo'));
 194                 common_element_end('a');
 195         } else {
 196                 common_element_start('p', array('id' => 'branding'));
 197                 common_element('a', array('href' => common_local_url('public')),
 198                                            $config['site']['name']);
 199                 common_element_end('p');
 200         }
 201
 202         common_element('h1', 'pagetitle', $pagetitle);
 203
 204         if ($headercall) {
 205                 if ($data) {
 206                         call_user_func($headercall, $data);
 207                 } else {
 208                         call_user_func($headercall);
 209                 }
 210         }
 211         common_element_end('div');
 212         common_element_start('div', array('id' => 'content'));
 213 }
 214
 215 function common_show_footer() {
 216         global $xw, $config;
 217         common_element_end('div'); # content div
 218         common_foot_menu();
 219         common_element_start('div', array('id' => 'footer'));
 220         common_element_start('p', 'laconica');
 221         common_text(_t('This site is running the '));
 222         common_element('a', array('class' => 'software',
 223                                                           href => 'http://laconi.ca/'),
 224                                    'Laconica');
 225         common_text(_t('microblogging tool, version ' . LACONICA_VERSION . ', available under the '));
 226         common_element('a', array(href => 'http://www.fsf.org/licensing/licenses/agpl-3.0.html'),
 227                                    'GNU Affero General Public License');
 228         common_text(_t('.'));
 229         common_element_end('p');
 230         common_element('img', array('id' => 'cc',
 231                                                                 'src' => $config['license']['image'],
 232                                                                 'alt' => $config['license']['title']));
 233         common_element_start('p');
 234         common_text(_t('Unless otherwise specified, contents of this site are copyright by the contributors and available under the '));
 235         common_element('a', array('class' => 'license',
 236                                                           'rel' => 'license',
 237                                                           href => $config['license']['url']),
 238                                    $config['license']['title']);
 239         common_text(_t('. Contributors should be attributed by full name or nickname.'));
 240         common_element_end('p');
 241         common_element_end('div');
 242         common_element_end('div');
 243         common_element_end('body');
 244         common_element_end('html');
 245         common_end_xml();
 246 }
 247
 248 function common_text($txt) {
 249         global $xw;
 250         $xw->text($txt);
 251 }
 252
 253 function common_raw($xml) {
 254         global $xw;
 255         $xw->writeRaw($xml);
 256 }
 257
 258 function common_nav_menu() {
 259         $user = common_current_user();
 260         common_element_start('ul', array('id' => 'nav'));
 261         if ($user) {
 262                 common_menu_item(common_local_url('all', array('nickname' => $user->nickname)),
 263                                                  _t('Home'));
 264         }
 265         common_menu_item(common_local_url('public'), _t('Public'));
 266         common_menu_item(common_local_url('doc', array('title' => 'help')),
 267                                          _t('Help'));
 268         if ($user) {
 269                 common_menu_item(common_local_url('profilesettings'),
 270                                                  _t('Settings'));
 271                 common_menu_item(common_local_url('logout'),
 272                                                  _t('Logout'));
 273         } else {
 274                 common_menu_item(common_local_url('login'), _t('Login'));
 275                 common_menu_item(common_local_url('register'), _t('Register'));
 276                 common_menu_item(common_local_url('openidlogin'), _t('OpenID'));
 277         }
 278         common_element_end('ul');
 279 }
 280
 281 function common_foot_menu() {
 282         common_element_start('ul', array('id' => 'nav_sub'));
 283         common_menu_item(common_local_url('doc', array('title' => 'about')),
 284                                          _t('About'));
 285         common_menu_item(common_local_url('doc', array('title' => 'privacy')),
 286                                          _t('Privacy'));
 287         common_menu_item(common_local_url('doc', array('title' => 'source')),
 288                                          _t('Source'));
 289         common_element_end('ul');
 290 }
 291
 292 function common_menu_item($url, $text, $title=NULL, $is_selected=false) {
 293         $lattrs = array();
 294         if ($is_selected) {
 295                 $lattrs['class'] = 'current';
 296         }
 297         common_element_start('li', $lattrs);
 298         $attrs['href'] = $url;
 299         if ($title) {
 300                 $attrs['title'] = $title;
 301         }
 302         common_element('a', $attrs, $text);
 303         common_element_end('li');
 304 }
 305
 306 function common_input($id, $label, $value=NULL,$instructions=NULL) {
 307         common_element_start('p');
 308         common_element('label', array('for' => $id), $label);
 309         $attrs = array('name' => $id,
 310                                    'type' => 'text',
 311                                    'id' => $id);
 312         if ($value) {
 313                 $attrs['value'] = htmlspecialchars($value);
 314         }
 315         common_element('input', $attrs);
 316         if ($instructions) {
 317                 common_element('span', 'input_instructions', $instructions);
 318         }
 319         common_element_end('p');
 320 }
 321
 322 function common_hidden($id, $value) {
 323         common_element('input', array('name' => $id,
 324                                                                   'type' => 'hidden',
 325                                                                   'id' => $id,
 326                                                                   'value' => $value));
 327 }
 328
 329 function common_password($id, $label, $instructions=NULL) {
 330         common_element_start('p');
 331         common_element('label', array('for' => $id), $label);
 332         $attrs = array('name' => $id,
 333                                    'type' => 'password',
 334                                    'id' => $id);
 335         common_element('input', $attrs);
 336         if ($instructions) {
 337                 common_element('span', 'input_instructions', $instructions);
 338         }
 339         common_element_end('p');
 340 }
 341
 342 function common_submit($id, $label) {
 343         global $xw;
 344         common_element_start('p');
 345         common_element('input', array('type' => 'submit',
 346                                                                   'id' => $id,
 347                                                                   'name' => $id,
 348                                                                   'class' => 'submit',
 349                                                                   'value' => $label));
 350         common_element_end('p');
 351 }
 352
 353 function common_textarea($id, $label, $content=NULL, $instructions=NULL) {
 354         common_element_start('p');
 355         common_element('label', array('for' => $id), $label);
 356         common_element('textarea', array('rows' => 3,
 357                                                                          'cols' => 40,
 358                                                                          'name' => $id,
 359                                                                          'id' => $id),
 360                                    ($content) ? $content : ' ');
 361         if ($instructions) {
 362                 common_element('span', 'input_instructions', $instructions);
 363         }
 364         common_element_end('p');
 365 }
 366
 367 # salted, hashed passwords are stored in the DB
 368
 369 function common_munge_password($password, $id) {
 370         return md5($password . $id);
 371 }
 372
 373 # check if a username exists and has matching password
 374 function common_check_user($nickname, $password) {
 375         $user = User::staticGet('nickname', $nickname);
 376         if (is_null($user)) {
 377                 return false;
 378         } else {
 379                 return (0 == strcmp(common_munge_password($password, $user->id),
 380                                                         $user->password));
 381         }
 382 }
 383
 384 # is the current user logged in?
 385 function common_logged_in() {
 386         return (!is_null(common_current_user()));
 387 }
 388
 389 function common_have_session() {
 390         return (0 != strcmp(session_id(), ''));
 391 }
 392
 393 function common_ensure_session() {
 394         if (!common_have_session()) {
 395                 @session_start();
 396         }
 397 }
 398
 399 function common_set_user($nickname) {
 400         if (is_null($nickname) && common_have_session()) {
 401                 unset($_SESSION['userid']);
 402                 return true;
 403         } else {
 404                 $user = User::staticGet('nickname', $nickname);
 405                 if ($user) {
 406                         common_ensure_session();
 407                         $_SESSION['userid'] = $user->id;
 408                         return true;
 409                 } else {
 410                         return false;
 411                 }
 412         }
 413         return false;
 414 }
 415
 416 # who is the current user?
 417 function common_current_user() {
 418         common_ensure_session();
 419         $id = $_SESSION['userid'];
 420         if ($id) {
 421                 $user = User::staticGet($id);
 422         }
 423         return $user;
 424 }
 425
 426 # get canonical version of nickname for comparison
 427 function common_canonical_nickname($nickname) {
 428         # XXX: UTF-8 canonicalization (like combining chars)
 429         return strtolower($nickname);
 430 }
 431
 432 # get canonical version of email for comparison
 433 function common_canonical_email($email) {
 434         # XXX: canonicalize UTF-8
 435         # XXX: lcase the domain part
 436         return $email;
 437 }
 438
 439 define('URL_REGEX', '^|[ \t\r\n])((ftp|http|https|gopher|mailto|news|nntp|telnet|wais|file|prospero|aim|webcal):(([A-Za-z0-9$_.+!*(),;/?:@&~=-])|%[A-Fa-f0-9]{2}){2,}(#([a-zA-Z0-9][a-zA-Z0-9$_.+!*(),;/?:@&~=%-]*))?([A-Za-z0-9$_+!*();/?:~-]))');
 440
 441 function common_render_content($text, $notice) {
 442         $r = htmlspecialchars($text);
 443         $id = $notice->profile_id;
 444         $r = preg_replace('@https?://\S+@', '<a href="\0" class="extlink">\0</a>', $r);
 445         $r = preg_replace('/(^|\s+)@([a-z0-9]{1,64})/e', "'\\1@'.common_at_link($id, '\\2')", $r);
 446         # XXX: # tags
 447         # XXX: machine tags
 448         return $r;
 449 }
 450
 451 function common_at_link($sender_id, $nickname) {
 452         # Try to find profiles this profile is subscribed to that have this nickname
 453         $recipient = new Profile();
 454         # XXX: chokety and bad
 455         $recipient->whereAdd('EXISTS (SELECT subscribed from subscription where subscriber = '.$sender_id.' and subscribed = id)', 'AND');
 456         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 457         if ($recipient->find(TRUE)) {
 458                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistenee">'.$nickname.'</a>';
 459         }
 460         # Try to find profiles that listen to this profile and that have this nickname
 461         $recipient = new Profile();
 462         # XXX: chokety and bad
 463         $recipient->whereAdd('EXISTS (SELECT subscriber from subscription where subscribed = '.$sender_id.' and subscriber = id)', 'AND');
 464         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 465         if ($recipient->find(TRUE)) {
 466                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistener">'.$nickname.'</a>';
 467         }
 468         # If this is a local user, try to find a local user with that nickname.
 469         $sender = User::staticGet($sender_id);
 470         if ($sender) {
 471                 $recipient_user = User::staticGet('nickname', $nickname);
 472                 if ($recipient_user) {
 473                         return '<a href="'.htmlspecialchars(common_profile_url($nickname)).'" class="atlink usertouser">'.$nickname.'</a>';
 474                 }
 475         }
 476         # Otherwise, no links. @messages from local users to remote users,
 477         # or from remote users to other remote users, are just
 478         # outside our ability to make intelligent guesses about
 479         return $nickname;
 480 }
 481
 482 // where should the avatar go for this user?
 483
 484 function common_avatar_filename($id, $extension, $size=NULL, $extra=NULL) {
 485         global $config;
 486
 487         if ($size) {
 488                 return $id . '-' . $size . (($extra) ? ('-' . $extra) : '') . $extension;
 489         } else {
 490                 return $id . '-original' . (($extra) ? ('-' . $extra) : '') . $extension;
 491         }
 492 }
 493
 494 function common_avatar_path($filename) {
 495         global $config;
 496         return INSTALLDIR . '/avatar/' . $filename;
 497 }
 498
 499 function common_avatar_url($filename) {
 500         return common_path('avatar/'.$filename);
 501 }
 502
 503 function common_default_avatar($size) {
 504         static $sizenames = array(AVATAR_PROFILE_SIZE => 'profile',
 505                                                           AVATAR_STREAM_SIZE => 'stream',
 506                                                           AVATAR_MINI_SIZE => 'mini');
 507         return theme_path('default-avatar-'.$sizenames[$size].'.png');
 508 }
 509
 510 function common_local_url($action, $args=NULL) {
 511         global $config;
 512         if ($config['site']['fancy']) {
 513                 return common_fancy_url($action, $args);
 514         } else {
 515                 return common_simple_url($action, $args);
 516         }
 517 }
 518
 519 function common_fancy_url($action, $args=NULL) {
 520         switch (strtolower($action)) {
 521          case 'public':
 522                 if ($args && $args['page']) {
 523                         return common_path('?page=' . $args['page']);
 524                 } else {
 525                         return common_path('');
 526                 }
 527          case 'publicrss':
 528                 return common_path('rss');
 529          case 'publicxrds':
 530                 return common_path('xrds');
 531          case 'doc':
 532                 return common_path('doc/'.$args['title']);
 533          case 'login':
 534          case 'logout':
 535          case 'register':
 536          case 'subscribe':
 537          case 'unsubscribe':
 538                 return common_path('main/'.$action);
 539          case 'openidlogin':
 540                 return common_path('main/openid');
 541          case 'avatar':
 542          case 'password':
 543                 return common_path('settings/'.$action);
 544          case 'profilesettings':
 545                 return common_path('settings/profile');
 546          case 'openidsettings':
 547                 return common_path('settings/openid');
 548          case 'newnotice':
 549                 return common_path('notice/new');
 550          case 'shownotice':
 551                 return common_path('notice/'.$args['notice']);
 552          case 'xrds':
 553          case 'foaf':
 554                 return common_path($args['nickname'].'/'.$action);
 555          case 'subscriptions':
 556          case 'subscribers':
 557          case 'all':
 558                 if ($args && $args['page']) {
 559                         return common_path($args['nickname'].'/'.$action.'?page=' . $args['page']);
 560                 } else {
 561                         return common_path($args['nickname'].'/'.$action);
 562                 }
 563          case 'allrss':
 564                 return common_path($args['nickname'].'/all/rss');
 565          case 'userrss':
 566                 return common_path($args['nickname'].'/rss');
 567          case 'showstream':
 568                 if ($args && $args['page']) {
 569                         return common_path($args['nickname'].'?page=' . $args['page']);
 570                 } else {
 571                         return common_path($args['nickname']);
 572                 }
 573          case 'confirmemail':
 574                 return common_path('main/confirmemail/'.$args['code']);
 575          case 'userbyid':
 576                 return common_path('user/'.$args['id']);
 577          default:
 578                 return common_simple_url($action, $args);
 579         }
 580 }
 581
 582 function common_simple_url($action, $args=NULL) {
 583         global $config;
 584         /* XXX: pretty URLs */
 585         $extra = '';
 586         if ($args) {
 587                 foreach ($args as $key => $value) {
 588                         $extra .= "&${key}=${value}";
 589                 }
 590         }
 591         return common_path("index.php?action=${action}${extra}");
 592 }
 593
 594 function common_path($relative) {
 595         global $config;
 596         $pathpart = ($config['site']['path']) ? $config['site']['path']."/" : '';
 597         return "http://".$config['site']['server'].'/'.$pathpart.$relative;
 598 }
 599
 600 function common_date_string($dt) {
 601         // XXX: do some sexy date formatting
 602         // return date(DATE_RFC822, $dt);
 603         return $dt;
 604 }
 605
 606 function common_date_w3dtf($dt) {
 607         $t = strtotime($dt);
 608         return date(DATE_W3C, $t);
 609 }
 610
 611 function common_redirect($url, $code=307) {
 612         static $status = array(301 => "Moved Permanently",
 613                                                    302 => "Found",
 614                                                    303 => "See Other",
 615                                                    307 => "Temporary Redirect");
 616         header("Status: ${code} $status[$code]");
 617         header("Location: $url");
 618
 619         common_start_xml('a',
 620                                          '-//W3C//DTD XHTML 1.0 Strict//EN',
 621                                          'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd');
 622         common_element('a', array('href' => $url), $url);
 623         common_end_xml();
 624 }
 625
 626 function common_broadcast_notice($notice, $remote=false) {
 627         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 628         if (!$remote) {
 629                 # Make sure we have the OMB stuff
 630                 require_once(INSTALLDIR.'/lib/omb.php');
 631                 omb_broadcast_remote_subscribers($notice);
 632         }
 633         // XXX: broadcast notices to Jabber
 634         // XXX: broadcast notices to SMS
 635         // XXX: broadcast notices to other IM
 636         return true;
 637 }
 638
 639 function common_broadcast_profile($profile) {
 640         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 641         require_once(INSTALLDIR.'/lib/omb.php');
 642         omb_broadcast_profile($profile);
 643         // XXX: Other broadcasts...?
 644         return true;
 645 }
 646
 647 function common_profile_url($nickname) {
 648         return common_local_url('showstream', array('nickname' => $nickname));
 649 }
 650
 651 # Don't call if nobody's logged in
 652
 653 function common_notice_form($action=NULL) {
 654         $user = common_current_user();
 655         assert(!is_null($user));
 656         common_element_start('form', array('id' => 'status_form',
 657                                                                            'method' => 'POST',
 658                                                                            'action' => common_local_url('newnotice')));
 659         common_element_start('p');
 660         common_element('label', array('for' => 'status_update',
 661                                                                   'id' => 'status_label'),
 662                                    _t('What\'s up, ').$user->nickname.'?');
 663         common_element('textarea', array('id' => 'status_textarea',
 664                                                                          'name' => 'status_textarea'),
 665                                    ' ');
 666         if ($action) {
 667                 common_hidden('returnto', $action);
 668         }
 669         common_element('input', array('id' => 'status_submit',
 670                                                                   'name' => 'status_submit',
 671                                                                   'type' => 'submit',
 672                                                                   'value' => _t('Send')));
 673         common_element_end('p');
 674         common_element_end('form');
 675 }
 676
 677 function common_mint_tag($extra) {
 678         global $config;
 679         return
 680           'tag:'.$config['tag']['authority'].','.
 681           $config['tag']['date'].':'.$config['tag']['prefix'].$extra;
 682 }
 683
 684 # Should make up a reasonable root URL
 685
 686 function common_root_url() {
 687         return common_path('');
 688 }
 689
 690 # returns $bytes bytes of random data as a hexadecimal string
 691 # "good" here is a goal and not a guarantee
 692
 693 function common_good_rand($bytes) {
 694         # XXX: use random.org...?
 695         if (file_exists('/dev/urandom')) {
 696                 return common_urandom($bytes);
 697         } else { # FIXME: this is probably not good enough
 698                 return common_mtrand($bytes);
 699         }
 700 }
 701
 702 function common_urandom($bytes) {
 703         $h = fopen('/dev/urandom', 'rb');
 704         # should not block
 705         $src = fread($h, $bytes);
 706         fclose($h);
 707         $enc = '';
 708         for ($i = 0; $i < $bytes; $i++) {
 709                 $enc .= sprintf("%02x", (ord($src[$i])));
 710         }
 711         return $enc;
 712 }
 713
 714 function common_mtrand($bytes) {
 715         $enc = '';
 716         for ($i = 0; $i < $bytes; $i++) {
 717                 $enc .= sprintf("%02x", mt_rand(0, 255));
 718         }
 719         return $enc;
 720 }
 721
 722 function common_set_returnto($url) {
 723         common_ensure_session();
 724         $_SESSION['returnto'] = $url;
 725 }
 726
 727 function common_get_returnto() {
 728         common_ensure_session();
 729         return $_SESSION['returnto'];
 730 }
 731
 732 function common_timestamp() {
 733         return date('YmdHis');
 734 }
 735
 736 // XXX: set up gettext
 737
 738 function _t($str) {
 739         return $str;
 740 }
 741
 742 function common_ensure_syslog() {
 743         static $initialized = false;
 744         if (!$initialized) {
 745                 global $config;
 746                 define_syslog_variables();
 747                 openlog($config['syslog']['appname'], 0, LOG_USER);
 748                 $initialized = true;
 749         }
 750 }
 751
 752 function common_log($priority, $msg, $filename=NULL) {
 753         common_ensure_syslog();
 754         syslog($priority, $msg);
 755 }
 756
 757 function common_debug($msg, $filename=NULL) {
 758         if ($filename) {
 759                 common_log(LOG_DEBUG, basename($filename).' - '.$msg);
 760         } else {
 761                 common_log(LOG_DEBUG, $msg);
 762         }
 763 }
 764
 765 function common_valid_http_url($url) {
 766         return Validate::uri($url, array('allowed_schemes' => array('http', 'https')));
 767 }
 768
 769 function common_valid_tag($tag) {
 770         if (preg_match('/^tag:(.*?),(\d{4}(-\d{2}(-\d{2})?)?):(.*)$/', $tag, $matches)) {
 771                 return (Validate::email($matches[1]) ||
 772                                 preg_match('/^([\w-\.]+)$/', $matches[1]));
 773         }
 774         return false;
 775 }
 776
 777 # Does a little before-after block for next/prev page
 778
 779 function common_pagination($have_before, $have_after, $page, $action, $args=NULL) {
 780
 781         if ($have_before || $have_after) {
 782                 common_element_start('div', array('id' => 'pagination'));
 783                 common_element_start('ul', array('id' => 'nav_pagination'));
 784         }
 785
 786         if ($have_before) {
 787                 $pargs = array('page' => $page-1);
 788                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 789
 790                 common_element_start('li', 'before');
 791                 common_element('a', array('href' => common_local_url($action, $newargs)),
 792                                            _t('« After'));
 793                 common_element_end('li');
 794         }
 795
 796         if ($have_after) {
 797                 $pargs = array('page' => $page+1);
 798                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 799                 common_element_start('li', 'after');
 800                 common_element('a', array('href' => common_local_url($action, $newargs)),
 801                                                    _t('Before »'));
 802                 common_element_end('li');
 803         }
 804
 805         if ($have_before || $have_after) {
 806                 common_element_end('ul');
 807                 common_element_end('div');
 808         }
 809 }
 810
 811 /* Following functions are copied from MediaWiki GlobalFunctions.php
 812  * and written by Evan Prodromou. */
 813
 814 function common_accept_to_prefs($accept, $def = '*/*') {
 815         # No arg means accept anything (per HTTP spec)
 816         if(!$accept) {
 817                 return array($def => 1);
 818         }
 819
 820         $prefs = array();
 821
 822         $parts = explode(',', $accept);
 823
 824         foreach($parts as $part) {
 825                 # FIXME: doesn't deal with params like 'text/html; level=1'
 826                 @list($value, $qpart) = explode(';', $part);
 827                 $match = array();
 828                 if(!isset($qpart)) {
 829                         $prefs[$value] = 1;
 830                 } elseif(preg_match('/q\s*=\s*(\d*\.\d+)/', $qpart, $match)) {
 831                         $prefs[$value] = $match[1];
 832                 }
 833         }
 834
 835         return $prefs;
 836 }
 837
 838 function common_mime_type_match($type, $avail) {
 839         if(array_key_exists($type, $avail)) {
 840                 return $type;
 841         } else {
 842                 $parts = explode('/', $type);
 843                 if(array_key_exists($parts[0] . '/*', $avail)) {
 844                         return $parts[0] . '/*';
 845                 } elseif(array_key_exists('*/*', $avail)) {
 846                         return '*/*';
 847                 } else {
 848                         return NULL;
 849                 }
 850         }
 851 }
 852
 853 function common_negotiate_type($cprefs, $sprefs) {
 854         $combine = array();
 855
 856         foreach(array_keys($sprefs) as $type) {
 857                 $parts = explode('/', $type);
 858                 if($parts[1] != '*') {
 859                         $ckey = common_mime_type_match($type, $cprefs);
 860                         if($ckey) {
 861                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
 862                         }
 863                 }
 864         }
 865
 866         foreach(array_keys($cprefs) as $type) {
 867                 $parts = explode('/', $type);
 868                 if($parts[1] != '*' && !array_key_exists($type, $sprefs)) {
 869                         $skey = common_mime_type_match($type, $sprefs);
 870                         if($skey) {
 871                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
 872                         }
 873                 }
 874         }
 875
 876         $bestq = 0;
 877         $besttype = NULL;
 878
 879         foreach(array_keys($combine) as $type) {
 880                 if($combine[$type] > $bestq) {
 881                         $besttype = $type;
 882                         $bestq = $combine[$type];
 883                 }
 884         }
 885
 886         return $besttype;
 887 }
 888
 889 function common_config($main, $sub) {
 890         global $config;
 891         return $config[$main][$sub];
 892 }
 893
 894 function common_copy_args($from) {
 895         $to = array();
 896         $strip = get_magic_quotes_gpc();
 897         foreach ($from as $k => $v) {
 898                 $to[$k] = ($strip) ? stripslashes($v) : $v;
 899         }
 900         return $to;
 901 }
 902
 903 function common_user_uri(&$user) {
 904         return common_local_url('userbyid', array('id' => $user->id));
 905 }
 906
 907 function common_notice_uri(&$notice) {
 908         return common_local_url('shownotice',
 909                 array('notice' => $notice->id));
 910 }