lib/activityobject.php

   1 <?php
   2 /**
   3  * StatusNet, the distributed open-source microblogging tool
   4  *
   5  * An activity
   6  *
   7  * PHP version 5
   8  *
   9  * LICENCE: This program is free software: you can redistribute it and/or modify
  10  * it under the terms of the GNU Affero General Public License as published by
  11  * the Free Software Foundation, either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU Affero General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Affero General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  *
  22  * @category  Feed
  23  * @package   StatusNet
  24  * @author    Evan Prodromou <evan@status.net>
  25  * @author    Zach Copley <zach@status.net>
  26  * @copyright 2010 StatusNet, Inc.
  27  * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPLv3
  28  * @link      http://status.net/
  29  */
  30
  31 if (!defined('STATUSNET')) {
  32     exit(1);
  33 }
  34
  35 require_once(INSTALLDIR.'/lib/activitystreamjsondocument.php');
  36
  37 /**
  38  * A noun-ish thing in the activity universe
  39  *
  40  * The activity streams spec talks about activity objects, while also having
  41  * a tag activity:object, which is in fact an activity object. Aaaaaah!
  42  *
  43  * This is just a thing in the activity universe. Can be the subject, object,
  44  * or indirect object (target!) of an activity verb. Rotten name, and I'm
  45  * propagating it. *sigh*
  46  *
  47  * @category  OStatus
  48  * @package   StatusNet
  49  * @author    Evan Prodromou <evan@status.net>
  50  * @copyright 2010 StatusNet, Inc.
  51  * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPLv3
  52  * @link      http://status.net/
  53  */
  54 class ActivityObject
  55 {
  56     const ARTICLE   = 'http://activitystrea.ms/schema/1.0/article';
  57     const BLOGENTRY = 'http://activitystrea.ms/schema/1.0/blog-entry';
  58     const NOTE      = 'http://activitystrea.ms/schema/1.0/note';
  59     const STATUS    = 'http://activitystrea.ms/schema/1.0/status';
  60     const FILE      = 'http://activitystrea.ms/schema/1.0/file';
  61     const PHOTO     = 'http://activitystrea.ms/schema/1.0/photo';
  62     const ALBUM     = 'http://activitystrea.ms/schema/1.0/photo-album';
  63     const PLAYLIST  = 'http://activitystrea.ms/schema/1.0/playlist';
  64     const VIDEO     = 'http://activitystrea.ms/schema/1.0/video';
  65     const AUDIO     = 'http://activitystrea.ms/schema/1.0/audio';
  66     const BOOKMARK  = 'http://activitystrea.ms/schema/1.0/bookmark';
  67     const PERSON    = 'http://activitystrea.ms/schema/1.0/person';
  68     const GROUP     = 'http://activitystrea.ms/schema/1.0/group';
  69     const _LIST     = 'http://activitystrea.ms/schema/1.0/list'; // LIST is reserved
  70     const PLACE     = 'http://activitystrea.ms/schema/1.0/place';
  71     const COMMENT   = 'http://activitystrea.ms/schema/1.0/comment';
  72     // ^^^^^^^^^^ tea!
  73     const ACTIVITY = 'http://activitystrea.ms/schema/1.0/activity';
  74     const SERVICE   = 'http://activitystrea.ms/schema/1.0/service';
  75     const IMAGE     = 'http://activitystrea.ms/schema/1.0/image';
  76     const COLLECTION = 'http://activitystrea.ms/schema/1.0/collection';
  77     const APPLICATION = 'http://activitystrea.ms/schema/1.0/application';
  78
  79     // Atom elements we snarf
  80
  81     const TITLE   = 'title';
  82     const SUMMARY = 'summary';
  83     const ID      = 'id';
  84     const SOURCE  = 'source';
  85
  86     const NAME  = 'name';
  87     const URI   = 'uri';
  88     const EMAIL = 'email';
  89
  90     const POSTEROUS   = 'http://posterous.com/help/rss/1.0';
  91     const AUTHOR      = 'author';
  92     const USERIMAGE   = 'userImage';
  93     const PROFILEURL  = 'profileUrl';
  94     const NICKNAME    = 'nickName';
  95     const DISPLAYNAME = 'displayName';
  96
  97     public $element;
  98     public $type;
  99     public $id;
 100     public $title;
 101     public $summary;
 102     public $content;
 103     public $owner;
 104     public $link;
 105     public $source;
 106     public $avatarLinks = array();
 107     public $geopoint;
 108     public $poco;
 109     public $displayName;
 110
 111     // @todo move this stuff to it's own PHOTO activity object
 112     const MEDIA_DESCRIPTION = 'description';
 113
 114     public $thumbnail;
 115     public $largerImage;
 116     public $description;
 117     public $extra = array();
 118
 119     public $stream;
 120
 121     /**
 122      * Constructor
 123      *
 124      * This probably needs to be refactored
 125      * to generate a local class (ActivityPerson, ActivityFile, ...)
 126      * based on the object type.
 127      *
 128      * @param DOMElement $element DOM thing to turn into an Activity thing
 129      */
 130     function __construct($element = null)
 131     {
 132         if (empty($element)) {
 133             return;
 134         }
 135
 136         $this->element = $element;
 137
 138         $this->geopoint = $this->_childContent(
 139             $element,
 140             ActivityContext::POINT,
 141             ActivityContext::GEORSS
 142         );
 143
 144         if ($element->tagName == 'author') {
 145             $this->_fromAuthor($element);
 146         } else if ($element->tagName == 'item') {
 147             $this->_fromRssItem($element);
 148         } else {
 149             $this->_fromAtomEntry($element);
 150         }
 151
 152         // Some per-type attributes...
 153         if ($this->type == self::PERSON || $this->type == self::GROUP) {
 154             $this->displayName = $this->title;
 155
 156             $photos = ActivityUtils::getLinks($element, 'photo');
 157             if (count($photos)) {
 158                 foreach ($photos as $link) {
 159                     $this->avatarLinks[] = new AvatarLink($link);
 160                 }
 161             } else {
 162                 $avatars = ActivityUtils::getLinks($element, 'avatar');
 163                 foreach ($avatars as $link) {
 164                     $this->avatarLinks[] = new AvatarLink($link);
 165                 }
 166             }
 167
 168             $this->poco = new PoCo($element);
 169         }
 170
 171         if ($this->type == self::PHOTO) {
 172
 173             $this->thumbnail   = ActivityUtils::getLink($element, 'preview');
 174             $this->largerImage = ActivityUtils::getLink($element, 'enclosure');
 175
 176             $this->description = ActivityUtils::childContent(
 177                 $element,
 178                 ActivityObject::MEDIA_DESCRIPTION,
 179                 Activity::MEDIA
 180             );
 181         }
 182         if ($this->type == self::_LIST) {
 183             $owner = ActivityUtils::child($this->element, Activity::AUTHOR, Activity::SPEC);
 184             $this->owner = new ActivityObject($owner);
 185         }
 186     }
 187
 188     private function _fromAuthor($element)
 189     {
 190         $this->type = $this->_childContent($element,
 191                                            Activity::OBJECTTYPE,
 192                                            Activity::SPEC);
 193
 194         if (empty($this->type)) {
 195             $this->type = self::PERSON; // XXX: is this fair?
 196         }
 197
 198         // start with <atom:title>
 199
 200         $title = ActivityUtils::childHtmlContent($element, self::TITLE);
 201
 202         if (!empty($title)) {
 203             $this->title = html_entity_decode(strip_tags($title), ENT_QUOTES, 'UTF-8');
 204         }
 205
 206         // fall back to <atom:name>
 207
 208         if (empty($this->title)) {
 209             $this->title = $this->_childContent($element, self::NAME);
 210         }
 211
 212         // start with <atom:id>
 213
 214         $this->id = $this->_childContent($element, self::ID);
 215
 216         // fall back to <atom:uri>
 217
 218         if (empty($this->id)) {
 219             $this->id = $this->_childContent($element, self::URI);
 220         }
 221
 222         // fall further back to <atom:email>
 223
 224         if (empty($this->id)) {
 225             $email = $this->_childContent($element, self::EMAIL);
 226             if (!empty($email)) {
 227                 // XXX: acct: ?
 228                 $this->id = 'mailto:'.$email;
 229             }
 230         }
 231
 232         $this->link = ActivityUtils::getPermalink($element);
 233
 234         // fall finally back to <link rel=alternate>
 235
 236         if (empty($this->id) && !empty($this->link)) { // fallback if there's no ID
 237             $this->id = $this->link;
 238         }
 239     }
 240
 241     private function _fromAtomEntry($element)
 242     {
 243         $this->type = $this->_childContent($element, Activity::OBJECTTYPE,
 244                                            Activity::SPEC);
 245
 246         if (empty($this->type)) {
 247             $this->type = ActivityObject::NOTE;
 248         }
 249
 250         $this->summary = ActivityUtils::childHtmlContent($element, self::SUMMARY);
 251         $this->content = ActivityUtils::getContent($element);
 252
 253         // We don't like HTML in our titles, although it's technically allowed
 254
 255         $title = ActivityUtils::childHtmlContent($element, self::TITLE);
 256
 257         $this->title = html_entity_decode(strip_tags($title), ENT_QUOTES, 'UTF-8');
 258
 259         $this->source  = $this->_getSource($element);
 260
 261         $this->link = ActivityUtils::getPermalink($element);
 262
 263         $this->id = $this->_childContent($element, self::ID);
 264
 265         if (empty($this->id) && !empty($this->link)) { // fallback if there's no ID
 266             $this->id = $this->link;
 267         }
 268     }
 269
 270     // @todo FIXME: rationalize with Activity::_fromRssItem()
 271     private function _fromRssItem($item)
 272     {
 273         $this->title = ActivityUtils::childContent($item, ActivityObject::TITLE, Activity::RSS);
 274
 275         $contentEl = ActivityUtils::child($item, ActivityUtils::CONTENT, Activity::CONTENTNS);
 276
 277         if (!empty($contentEl)) {
 278             $this->content = htmlspecialchars_decode($contentEl->textContent, ENT_QUOTES);
 279         } else {
 280             $descriptionEl = ActivityUtils::child($item, Activity::DESCRIPTION, Activity::RSS);
 281             if (!empty($descriptionEl)) {
 282                 $this->content = htmlspecialchars_decode($descriptionEl->textContent, ENT_QUOTES);
 283             }
 284         }
 285
 286         $this->link = ActivityUtils::childContent($item, ActivityUtils::LINK, Activity::RSS);
 287
 288         $guidEl = ActivityUtils::child($item, Activity::GUID, Activity::RSS);
 289
 290         if (!empty($guidEl)) {
 291             $this->id = $guidEl->textContent;
 292
 293             if ($guidEl->hasAttribute('isPermaLink')) {
 294                 // overwrites <link>
 295                 $this->link = $this->id;
 296             }
 297         }
 298     }
 299
 300     public static function fromRssAuthor($el)
 301     {
 302         $text = $el->textContent;
 303
 304         if (preg_match('/^(.*?) \((.*)\)$/', $text, $match)) {
 305             $email = $match[1];
 306             $name = $match[2];
 307         } else if (preg_match('/^(.*?) <(.*)>$/', $text, $match)) {
 308             $name = $match[1];
 309             $email = $match[2];
 310         } else if (preg_match('/.*@.*/', $text)) {
 311             $email = $text;
 312             $name = null;
 313         } else {
 314             $name = $text;
 315             $email = null;
 316         }
 317
 318         // Not really enough info
 319
 320         $obj = new ActivityObject();
 321
 322         $obj->element = $el;
 323
 324         $obj->type  = ActivityObject::PERSON;
 325         $obj->title = $name;
 326
 327         if (!empty($email)) {
 328             $obj->id = 'mailto:'.$email;
 329         }
 330
 331         return $obj;
 332     }
 333
 334     public static function fromDcCreator($el)
 335     {
 336         // Not really enough info
 337
 338         $text = $el->textContent;
 339
 340         $obj = new ActivityObject();
 341
 342         $obj->element = $el;
 343
 344         $obj->title = $text;
 345         $obj->type  = ActivityObject::PERSON;
 346
 347         return $obj;
 348     }
 349
 350     public static function fromRssChannel($el)
 351     {
 352         $obj = new ActivityObject();
 353
 354         $obj->element = $el;
 355
 356         $obj->type = ActivityObject::PERSON; // @fixme guess better
 357
 358         $obj->title = ActivityUtils::childContent($el, ActivityObject::TITLE, Activity::RSS);
 359         $obj->link  = ActivityUtils::childContent($el, ActivityUtils::LINK, Activity::RSS);
 360         $obj->id    = ActivityUtils::getLink($el, Activity::SELF);
 361
 362         if (empty($obj->id)) {
 363             $obj->id = $obj->link;
 364         }
 365
 366         $desc = ActivityUtils::childContent($el, Activity::DESCRIPTION, Activity::RSS);
 367
 368         if (!empty($desc)) {
 369             $obj->content = htmlspecialchars_decode($desc, ENT_QUOTES);
 370         }
 371
 372         $imageEl = ActivityUtils::child($el, Activity::IMAGE, Activity::RSS);
 373
 374         if (!empty($imageEl)) {
 375             $url = ActivityUtils::childContent($imageEl, Activity::URL, Activity::RSS);
 376             $al = new AvatarLink();
 377             $al->url = $url;
 378             $obj->avatarLinks[] = $al;
 379         }
 380
 381         return $obj;
 382     }
 383
 384     public static function fromPosterousAuthor($el)
 385     {
 386         $obj = new ActivityObject();
 387
 388         $obj->type = ActivityObject::PERSON; // @fixme any others...?
 389
 390         $userImage = ActivityUtils::childContent($el, self::USERIMAGE, self::POSTEROUS);
 391
 392         if (!empty($userImage)) {
 393             $al = new AvatarLink();
 394             $al->url = $userImage;
 395             $obj->avatarLinks[] = $al;
 396         }
 397
 398         $obj->link = ActivityUtils::childContent($el, self::PROFILEURL, self::POSTEROUS);
 399         $obj->id   = $obj->link;
 400
 401         $obj->poco = new PoCo();
 402
 403         $obj->poco->preferredUsername = ActivityUtils::childContent($el, self::NICKNAME, self::POSTEROUS);
 404         $obj->poco->displayName       = ActivityUtils::childContent($el, self::DISPLAYNAME, self::POSTEROUS);
 405
 406         $obj->title = $obj->poco->displayName;
 407
 408         return $obj;
 409     }
 410
 411     private function _childContent($element, $tag, $namespace=ActivityUtils::ATOM)
 412     {
 413         return ActivityUtils::childContent($element, $tag, $namespace);
 414     }
 415
 416     // Try to get a unique id for the source feed
 417
 418     private function _getSource($element)
 419     {
 420         $sourceEl = ActivityUtils::child($element, 'source');
 421
 422         if (empty($sourceEl)) {
 423             return null;
 424         } else {
 425             $href = ActivityUtils::getLink($sourceEl, 'self');
 426             if (!empty($href)) {
 427                 return $href;
 428             } else {
 429                 return ActivityUtils::childContent($sourceEl, 'id');
 430             }
 431         }
 432     }
 433
 434     static function fromNotice(Notice $notice)
 435     {
 436         $object = new ActivityObject();
 437
 438         if (Event::handle('StartActivityObjectFromNotice', array($notice, &$object))) {
 439
 440             $object->type    = (empty($notice->object_type)) ? ActivityObject::NOTE : $notice->object_type;
 441
 442             $object->id      = $notice->uri;
 443             $object->title = 'New ' . self::canonicalType($object->type) . ' by ';
 444             try {
 445                 $object->title .= $notice->getProfile()->getAcctUri();
 446             } catch (ProfileNoAcctUriException $e) {
 447                 $object->title .= $e->profile->nickname;
 448             }
 449             $object->content = $notice->rendered;
 450             $object->link    = $notice->getUrl();
 451
 452             $object->extra[] = array('status_net', array('notice_id' => $notice->id));
 453
 454             Event::handle('EndActivityObjectFromNotice', array($notice, &$object));
 455         }
 456
 457         return $object;
 458     }
 459
 460     static function fromGroup(User_group $group)
 461     {
 462         $object = new ActivityObject();
 463
 464         if (Event::handle('StartActivityObjectFromGroup', array($group, &$object))) {
 465
 466             $object->type   = ActivityObject::GROUP;
 467             $object->id     = $group->getUri();
 468             $object->title  = $group->getBestName();
 469             $object->link   = $group->getUri();
 470
 471             $object->avatarLinks[] = AvatarLink::fromFilename($group->homepage_logo,
 472                                                               AVATAR_PROFILE_SIZE);
 473
 474             $object->avatarLinks[] = AvatarLink::fromFilename($group->stream_logo,
 475                                                               AVATAR_STREAM_SIZE);
 476
 477             $object->avatarLinks[] = AvatarLink::fromFilename($group->mini_logo,
 478                                                               AVATAR_MINI_SIZE);
 479
 480             $object->poco = PoCo::fromGroup($group);
 481             Event::handle('EndActivityObjectFromGroup', array($group, &$object));
 482         }
 483
 484         return $object;
 485     }
 486
 487     static function fromPeopletag($ptag)
 488     {
 489         $object = new ActivityObject();
 490         if (Event::handle('StartActivityObjectFromPeopletag', array($ptag, &$object))) {
 491             $object->type    = ActivityObject::_LIST;
 492
 493             $object->id      = $ptag->getUri();
 494             $object->title   = $ptag->tag;
 495             $object->summary = $ptag->description;
 496             $object->link    = $ptag->homeUrl();
 497             $object->owner   = Profile::getKV('id', $ptag->tagger);
 498             $object->poco    = PoCo::fromProfile($object->owner);
 499             Event::handle('EndActivityObjectFromPeopletag', array($ptag, &$object));
 500         }
 501         return $object;
 502     }
 503
 504     static function fromFile(File $file)
 505     {
 506         $object = new ActivityObject();
 507
 508         if (Event::handle('StartActivityObjectFromFile', array($file, &$object))) {
 509
 510             $object->type = self::mimeTypeToObjectType($file->mimetype);
 511             $object->id   = TagURI::mint(sprintf("file:%d", $file->id));
 512             $object->link = common_local_url('attachment', array('attachment' => $file->id));
 513
 514             if ($file->title) {
 515                 $object->title = $file->title;
 516             }
 517
 518             if ($file->date) {
 519                 $object->date = $file->date;
 520             }
 521
 522             try {
 523                 $thumbnail = $file->getThumbnail();
 524                 $object->thumbnail = $thumbnail;
 525             } catch (UseFileAsThumbnailException $e) {
 526                 $object->thumbnail = null;
 527             } catch (UnsupportedMediaException $e) {
 528                 $object->thumbnail = null;
 529             }
 530
 531             switch (self::canonicalType($object->type)) {
 532             case 'image':
 533                 $object->largerImage = $file->url;
 534                 break;
 535             case 'video':
 536             case 'audio':
 537                 $object->stream = $file->url;
 538                 break;
 539             }
 540
 541             Event::handle('EndActivityObjectFromFile', array($file, &$object));
 542         }
 543
 544         return $object;
 545     }
 546
 547     static function fromNoticeSource(Notice_source $source)
 548     {
 549         $object = new ActivityObject();
 550         $wellKnown = array('web', 'xmpp', 'mail', 'omb', 'system', 'api', 'ostatus',
 551                            'activity', 'feed', 'mirror', 'twitter', 'facebook');
 552
 553         if (Event::handle('StartActivityObjectFromNoticeSource', array($source, &$object))) {
 554             $object->type = ActivityObject::APPLICATION;
 555
 556             if (in_array($source->code, $wellKnown)) {
 557                 // We use one ID for all well-known StatusNet sources
 558                 $object->id = "tag:status.net,2009:notice-source:".$source->code;
 559             } else if ($source->url) {
 560                 // They registered with an URL
 561                 $object->id = $source->url;
 562             } else {
 563                 // Locally-registered, no URL
 564                 $object->id = TagURI::mint("notice-source:".$source->code);
 565             }
 566
 567             if ($source->url) {
 568                 $object->link = $source->url;
 569             }
 570
 571             if ($source->name) {
 572                 $object->title = $source->name;
 573             } else {
 574                 $object->title = $source->code;
 575             }
 576
 577             if ($source->created) {
 578                 $object->date = $source->created;
 579             }
 580
 581             $object->extra[] = array('status_net', array('source_code' => $source->code));
 582
 583             Event::handle('EndActivityObjectFromNoticeSource', array($source, &$object));
 584         }
 585
 586         return $object;
 587     }
 588
 589     static function fromMessage(Message $message)
 590     {
 591         $object = new ActivityObject();
 592
 593         if (Event::handle('StartActivityObjectFromMessage', array($message, &$object))) {
 594
 595             $object->type    = ActivityObject::NOTE;
 596             $object->id      = ($message->uri) ? $message->uri : (($message->url) ? $message->url : TagURI::mint(sprintf("message:%d", $message->id)));
 597             $object->content = $message->rendered;
 598             $object->date    = $message->created;
 599
 600             if ($message->url) {
 601                 $object->link = $message->url;
 602             } else {
 603                 $object->link = common_local_url('showmessage', array('message' => $message->id));
 604             }
 605
 606             $object->extra[] = array('status_net', array('message_id' => $message->id));
 607
 608             Event::handle('EndActivityObjectFromMessage', array($message, &$object));
 609         }
 610
 611         return $object;
 612     }
 613
 614     function outputTo($xo, $tag='activity:object')
 615     {
 616         if (!empty($tag)) {
 617             $xo->elementStart($tag);
 618         }
 619
 620         if (Event::handle('StartActivityObjectOutputAtom', array($this, $xo))) {
 621             $xo->element('activity:object-type', null, $this->type);
 622
 623             // <author> uses URI
 624
 625             if ($tag == 'author') {
 626                 $xo->element(self::URI, null, $this->id);
 627             } else {
 628                 $xo->element(self::ID, null, $this->id);
 629             }
 630
 631             if (!empty($this->title)) {
 632                 $name = common_xml_safe_str($this->title);
 633                 if ($tag == 'author') {
 634                     // XXX: Backward compatibility hack -- atom:name should contain
 635                     // full name here, instead of nickname, i.e.: $name. Change
 636                     // this in the next version.
 637                     $xo->element(self::NAME, null, $this->poco->preferredUsername);
 638                 } else {
 639                     $xo->element(self::TITLE, null, $name);
 640                 }
 641             }
 642
 643             if (!empty($this->summary)) {
 644                 $xo->element(
 645                     self::SUMMARY,
 646                     null,
 647                     common_xml_safe_str($this->summary)
 648                 );
 649             }
 650
 651             if (!empty($this->content)) {
 652                 // XXX: assuming HTML content here
 653                 $xo->element(
 654                     ActivityUtils::CONTENT,
 655                     array('type' => 'html'),
 656                     common_xml_safe_str($this->content)
 657                 );
 658             }
 659
 660             if (!empty($this->link)) {
 661                 $xo->element(
 662                     'link',
 663                     array(
 664                         'rel' => 'alternate',
 665                         'type' => 'text/html',
 666                         'href' => $this->link
 667                     ),
 668                     null
 669                 );
 670             }
 671
 672             if(!empty($this->owner)) {
 673                 $owner = $this->owner->asActivityNoun(self::AUTHOR);
 674                 $xo->raw($owner);
 675             }
 676
 677             if ($this->type == ActivityObject::PERSON
 678                 || $this->type == ActivityObject::GROUP) {
 679
 680                 foreach ($this->avatarLinks as $alink) {
 681                     $xo->element('link',
 682                             array(
 683                                 'rel'          => 'avatar',
 684                                 'type'         => $alink->type,
 685                                 'media:width'  => $alink->width,
 686                                 'media:height' => $alink->height,
 687                                 'href'         => $alink->url,
 688                                 ),
 689                             null);
 690                 }
 691             }
 692
 693             if (!empty($this->geopoint)) {
 694                 $xo->element(
 695                     'georss:point',
 696                     null,
 697                     $this->geopoint
 698                 );
 699             }
 700
 701             if (!empty($this->poco)) {
 702                 $this->poco->outputTo($xo);
 703             }
 704
 705             // @fixme there's no way here to make a tree; elements can only contain plaintext
 706             // @fixme these may collide with JSON extensions
 707             foreach ($this->extra as $el) {
 708                 list($extraTag, $attrs, $content) = array_pad($el, 3, null);
 709                 $xo->element($extraTag, $attrs, $content);
 710             }
 711
 712             Event::handle('EndActivityObjectOutputAtom', array($this, $xo));
 713         }
 714
 715         if (!empty($tag)) {
 716             $xo->elementEnd($tag);
 717         }
 718
 719         return;
 720     }
 721
 722     function asString($tag='activity:object')
 723     {
 724         $xs = new XMLStringer(true);
 725
 726         $this->outputTo($xs, $tag);
 727
 728         return $xs->getString();
 729     }
 730
 731     /*
 732      * Returns an array based on this Activity Object suitable for
 733      * encoding as JSON.
 734      *
 735      * @return array $object the activity object array
 736      */
 737
 738     function asArray()
 739     {
 740         $object = array();
 741
 742         if (Event::handle('StartActivityObjectOutputJson', array($this, &$object))) {
 743             // XXX: attachments are added by Activity
 744
 745             // author (Add object for author? Could be useful for repeats.)
 746
 747             // content (Add rendered version of the notice?)
 748
 749             // downstreamDuplicates
 750
 751             // id
 752
 753             if ($this->id) {
 754                 $object['id'] = $this->id;
 755             } else if ($this->link) {
 756                 $object['id'] = $this->link;
 757             }
 758
 759             if ($this->type == ActivityObject::PERSON
 760                 || $this->type == ActivityObject::GROUP) {
 761
 762                 // displayName
 763                 $object['displayName'] = $this->title;
 764
 765                 // XXX: Not sure what the best avatar is to use for the
 766                 // author's "image". For now, I'm using the large size.
 767
 768                 $imgLink          = null;
 769                 $avatarMediaLinks = array();
 770
 771                 foreach ($this->avatarLinks as $a) {
 772
 773                     // Make a MediaLink for every other Avatar
 774                     $avatar = new ActivityStreamsMediaLink(
 775                         $a->url,
 776                         $a->width,
 777                         $a->height,
 778                         $a->type,
 779                         'avatar'
 780                     );
 781
 782                     // Find the big avatar to use as the "image"
 783                     if ($a->height == AVATAR_PROFILE_SIZE) {
 784                         $imgLink = $avatar;
 785                     }
 786
 787                     $avatarMediaLinks[] = $avatar->asArray();
 788                 }
 789
 790                 if (!array_key_exists('status_net', $object)) {
 791                     $object['status_net'] = array();
 792                 }
 793
 794                 $object['status_net']['avatarLinks'] = $avatarMediaLinks; // extension
 795
 796                 // image
 797                 if (!empty($imgLink)) {
 798                     $object['image']  = $imgLink->asArray();
 799                 }
 800             }
 801
 802             // objectType
 803             //
 804             // We can probably use the whole schema URL here but probably the
 805             // relative simple name is easier to parse
 806
 807             $object['objectType'] = self::canonicalType($this->type);
 808
 809             // summary
 810             $object['summary'] = $this->summary;
 811
 812             // content, usually rendered HTML
 813             $object['content'] = $this->content;
 814
 815             // published (probably don't need. Might be useful for repeats.)
 816
 817             // updated (probably don't need this)
 818
 819             // TODO: upstreamDuplicates
 820
 821             if ($this->link) {
 822                 $object['url'] = $this->link;
 823             }
 824
 825             /* Extensions */
 826             // @fixme these may collide with XML extensions
 827             // @fixme multiple tags of same name will overwrite each other
 828             // @fixme text content from XML extensions will be lost
 829
 830             foreach ($this->extra as $e) {
 831                 list($objectName, $props, $txt) = array_pad($e, 3, null);
 832                 if (!empty($objectName)) {
 833                     $parts = explode(":", $objectName);
 834                     if (count($parts) == 2 && $parts[0] == "statusnet") {
 835                         if (!array_key_exists('status_net', $object)) {
 836                             $object['status_net'] = array();
 837                         }
 838                         $object['status_net'][$parts[1]] = $props;
 839                     } else {
 840                         $object[$objectName] = $props;
 841                     }
 842                 }
 843             }
 844
 845             if (!empty($this->geopoint)) {
 846
 847                 list($lat, $lon) = explode(' ', $this->geopoint);
 848
 849                 if (!empty($lat) && !empty($lon)) {
 850                     $object['location'] = array(
 851                         'objectType' => 'place',
 852                         'position' => sprintf("%+02.5F%+03.5F/", $lat, $lon),
 853                         'lat' => $lat,
 854                         'lon' => $lon
 855                     );
 856
 857                     $loc = Location::fromLatLon((float)$lat, (float)$lon);
 858
 859                     if ($loc) {
 860                         $name = $loc->getName();
 861
 862                         if ($name) {
 863                             $object['location']['displayName'] = $name;
 864                         }
 865                         $url = $loc->getURL();
 866
 867                         if ($url) {
 868                             $object['location']['url'] = $url;
 869                         }
 870                     }
 871                 }
 872             }
 873
 874             if (!empty($this->poco)) {
 875                 $object['portablecontacts_net'] = array_filter($this->poco->asArray());
 876             }
 877
 878             if (!empty($this->thumbnail)) {
 879                 if (is_string($this->thumbnail)) {
 880                     $object['image'] = array('url' => $this->thumbnail);
 881                 } else {
 882                     $object['image'] = array('url' => $this->thumbnail->url);
 883                     if ($this->thumbnail->width) {
 884                         $object['image']['width'] = $this->thumbnail->width;
 885                     }
 886                     if ($this->thumbnail->height) {
 887                         $object['image']['height'] = $this->thumbnail->height;
 888                     }
 889                 }
 890             }
 891
 892             switch (self::canonicalType($this->type)) {
 893             case 'image':
 894                 if (!empty($this->largerImage)) {
 895                     $object['fullImage'] = array('url' => $this->largerImage);
 896                 }
 897                 break;
 898             case 'audio':
 899             case 'video':
 900                 if (!empty($this->stream)) {
 901                     $object['stream'] = array('url' => $this->stream);
 902                 }
 903                 break;
 904             }
 905
 906             Event::handle('EndActivityObjectOutputJson', array($this, &$object));
 907         }
 908         return array_filter($object);
 909     }
 910
 911     public function getIdentifiers() {
 912         $ids = array();
 913         foreach(array('id', 'link', 'url') as $id) {
 914             if (isset($this->$id)) {
 915                 $ids[] = $this->$id;
 916             }
 917         }
 918         return array_unique($ids);
 919     }
 920
 921     static function canonicalType($type) {
 922         return ActivityUtils::resolveUri($type, true);
 923     }
 924
 925     static function mimeTypeToObjectType($mimeType) {
 926         $ot = null;
 927
 928         // Default
 929
 930         if (empty($mimeType)) {
 931             return self::FILE;
 932         }
 933
 934         $parts = explode('/', $mimeType);
 935
 936         switch ($parts[0]) {
 937         case 'image':
 938             $ot = self::IMAGE;
 939             break;
 940         case 'audio':
 941             $ot = self::AUDIO;
 942             break;
 943         case 'video':
 944             $ot = self::VIDEO;
 945             break;
 946         default:
 947             $ot = self::FILE;
 948         }
 949
 950         return $ot;
 951     }
 952 }