lib/activity.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 /**
  36  * An activity in the ActivityStrea.ms world
  37  *
  38  * An activity is kind of like a sentence: someone did something
  39  * to something else.
  40  *
  41  * 'someone' is the 'actor'; 'did something' is the verb;
  42  * 'something else' is the object.
  43  *
  44  * @category  OStatus
  45  * @package   StatusNet
  46  * @author    Evan Prodromou <evan@status.net>
  47  * @copyright 2010 StatusNet, Inc.
  48  * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPLv3
  49  * @link      http://status.net/
  50  */
  51 class Activity
  52 {
  53     const SPEC   = 'http://activitystrea.ms/spec/1.0/';
  54     const SCHEMA = 'http://activitystrea.ms/schema/1.0/';
  55     const MEDIA  = 'http://purl.org/syndication/atommedia';
  56
  57     const VERB       = 'verb';
  58     const OBJECT     = 'object';
  59     const ACTOR      = 'actor';
  60     const SUBJECT    = 'subject';
  61     const OBJECTTYPE = 'object-type';
  62     const CONTEXT    = 'context';
  63     const TARGET     = 'target';
  64
  65     const ATOM = 'http://www.w3.org/2005/Atom';
  66
  67     const AUTHOR    = 'author';
  68     const PUBLISHED = 'published';
  69     const UPDATED   = 'updated';
  70
  71     const RSS = null; // no namespace!
  72
  73     const PUBDATE     = 'pubDate';
  74     const DESCRIPTION = 'description';
  75     const GUID        = 'guid';
  76     const SELF        = 'self';
  77     const IMAGE       = 'image';
  78     const URL         = 'url';
  79
  80     const DC = 'http://purl.org/dc/elements/1.1/';
  81
  82     const CREATOR = 'creator';
  83
  84     const CONTENTNS = 'http://purl.org/rss/1.0/modules/content/';
  85     const ENCODED = 'encoded';
  86
  87     public $actor;   // an ActivityObject
  88     public $verb;    // a string (the URL)
  89     public $objects = array();  // an array of ActivityObjects
  90     public $target;  // an ActivityObject
  91     public $context; // an ActivityObject
  92     public $time;    // Time of the activity
  93     public $link;    // an ActivityObject
  94     public $entry;   // the source entry
  95     public $feed;    // the source feed
  96
  97     public $summary; // summary of activity
  98     public $content; // HTML content of activity
  99     public $id;      // ID of the activity
 100     public $title;   // title of the activity
 101     public $categories = array(); // list of AtomCategory objects
 102     public $enclosures = array(); // list of enclosure URL references
 103
 104     public $extra = array(); // extra elements as array(tag, attrs, content)
 105     public $source;  // ActivitySource object representing 'home feed'
 106     public $selfLink; // <link rel='self' type='application/atom+xml'>
 107     public $editLink; // <link rel='edit' type='application/atom+xml'>
 108
 109     /**
 110      * Turns a regular old Atom <entry> into a magical activity
 111      *
 112      * @param DOMElement $entry Atom entry to poke at
 113      * @param DOMElement $feed  Atom feed, for context
 114      */
 115     function __construct($entry = null, $feed = null)
 116     {
 117         if (is_null($entry)) {
 118             return;
 119         }
 120
 121         // Insist on a feed's root DOMElement; don't allow a DOMDocument
 122         if ($feed instanceof DOMDocument) {
 123             throw new ClientException(
 124                 // TRANS: Client exception thrown when a feed instance is a DOMDocument.
 125                 _('Expecting a root feed element but got a whole XML document.')
 126             );
 127         }
 128
 129         $this->entry = $entry;
 130         $this->feed  = $feed;
 131
 132         if ($entry->namespaceURI == Activity::ATOM &&
 133             $entry->localName == 'entry') {
 134             $this->_fromAtomEntry($entry, $feed);
 135         } else if ($entry->namespaceURI == Activity::RSS &&
 136                    $entry->localName == 'item') {
 137             $this->_fromRssItem($entry, $feed);
 138         } else {
 139             // Low level exception. No need for i18n.
 140             throw new Exception("Unknown DOM element: {$entry->namespaceURI} {$entry->localName}");
 141         }
 142     }
 143
 144     function _fromAtomEntry($entry, $feed)
 145     {
 146         $pubEl = $this->_child($entry, self::PUBLISHED, self::ATOM);
 147
 148         if (!empty($pubEl)) {
 149             $this->time = strtotime($pubEl->textContent);
 150         } else {
 151             // XXX technically an error; being liberal. Good idea...?
 152             $updateEl = $this->_child($entry, self::UPDATED, self::ATOM);
 153             if (!empty($updateEl)) {
 154                 $this->time = strtotime($updateEl->textContent);
 155             } else {
 156                 $this->time = null;
 157             }
 158         }
 159
 160         $this->link = ActivityUtils::getPermalink($entry);
 161
 162         $verbEl = $this->_child($entry, self::VERB);
 163
 164         if (!empty($verbEl)) {
 165             $this->verb = trim($verbEl->textContent);
 166         } else {
 167             $this->verb = ActivityVerb::POST;
 168             // XXX: do other implied stuff here
 169         }
 170
 171         $objectEls = $entry->getElementsByTagNameNS(self::SPEC, self::OBJECT);
 172
 173         if ($objectEls->length > 0) {
 174             for ($i = 0; $i < $objectEls->length; $i++) {
 175                 $objectEl = $objectEls->item($i);
 176                 $this->objects[] = new ActivityObject($objectEl);
 177             }
 178         } else {
 179             $this->objects[] = new ActivityObject($entry);
 180         }
 181
 182         $actorEl = $this->_child($entry, self::ACTOR);
 183
 184         if (!empty($actorEl)) {
 185
 186             $this->actor = new ActivityObject($actorEl);
 187
 188             // Cliqset has bad actor IDs (just nickname of user). We
 189             // work around it by getting the author data and using its
 190             // id instead
 191
 192             if (!preg_match('/^\w+:/', $this->actor->id)) {
 193                 $authorEl = ActivityUtils::child($entry, 'author');
 194                 if (!empty($authorEl)) {
 195                     $authorObj = new ActivityObject($authorEl);
 196                     $this->actor->id = $authorObj->id;
 197                 }
 198             }
 199         } else if (!empty($feed) &&
 200                    $subjectEl = $this->_child($feed, self::SUBJECT)) {
 201
 202             $this->actor = new ActivityObject($subjectEl);
 203
 204         } else if ($authorEl = $this->_child($entry, self::AUTHOR, self::ATOM)) {
 205
 206             $this->actor = new ActivityObject($authorEl);
 207
 208         } else if (!empty($feed) && $authorEl = $this->_child($feed, self::AUTHOR,
 209                                                               self::ATOM)) {
 210
 211             $this->actor = new ActivityObject($authorEl);
 212         }
 213
 214         $contextEl = $this->_child($entry, self::CONTEXT);
 215
 216         if (!empty($contextEl)) {
 217             $this->context = new ActivityContext($contextEl);
 218         } else {
 219             $this->context = new ActivityContext($entry);
 220         }
 221
 222         $targetEl = $this->_child($entry, self::TARGET);
 223
 224         if (!empty($targetEl)) {
 225             $this->target = new ActivityObject($targetEl);
 226         }
 227
 228         $this->summary = ActivityUtils::childContent($entry, 'summary');
 229         $this->id      = ActivityUtils::childContent($entry, 'id');
 230         $this->content = ActivityUtils::getContent($entry);
 231
 232         $catEls = $entry->getElementsByTagNameNS(self::ATOM, 'category');
 233         if ($catEls) {
 234             for ($i = 0; $i < $catEls->length; $i++) {
 235                 $catEl = $catEls->item($i);
 236                 $this->categories[] = new AtomCategory($catEl);
 237             }
 238         }
 239
 240         foreach (ActivityUtils::getLinks($entry, 'enclosure') as $link) {
 241             $this->enclosures[] = $link->getAttribute('href');
 242         }
 243
 244         // From APP. Might be useful.
 245
 246         $this->selfLink = ActivityUtils::getLink($entry, 'self', 'application/atom+xml');
 247         $this->editLink = ActivityUtils::getLink($entry, 'edit', 'application/atom+xml');
 248     }
 249
 250     function _fromRssItem($item, $channel)
 251     {
 252         $verbEl = $this->_child($item, self::VERB);
 253
 254         if (!empty($verbEl)) {
 255             $this->verb = trim($verbEl->textContent);
 256         } else {
 257             $this->verb = ActivityVerb::POST;
 258             // XXX: do other implied stuff here
 259         }
 260
 261         $pubDateEl = $this->_child($item, self::PUBDATE, self::RSS);
 262
 263         if (!empty($pubDateEl)) {
 264             $this->time = strtotime($pubDateEl->textContent);
 265         }
 266
 267         if ($authorEl = $this->_child($item, self::AUTHOR, self::RSS)) {
 268             $this->actor = ActivityObject::fromRssAuthor($authorEl);
 269         } else if ($dcCreatorEl = $this->_child($item, self::CREATOR, self::DC)) {
 270             $this->actor = ActivityObject::fromDcCreator($dcCreatorEl);
 271         } else if ($posterousEl = $this->_child($item, ActivityObject::AUTHOR, ActivityObject::POSTEROUS)) {
 272             // Special case for Posterous.com
 273             $this->actor = ActivityObject::fromPosterousAuthor($posterousEl);
 274         } else if (!empty($channel)) {
 275             $this->actor = ActivityObject::fromRssChannel($channel);
 276         } else {
 277             // No actor!
 278         }
 279
 280         $this->title = ActivityUtils::childContent($item, ActivityObject::TITLE, self::RSS);
 281
 282         $contentEl = ActivityUtils::child($item, self::ENCODED, self::CONTENTNS);
 283
 284         if (!empty($contentEl)) {
 285             // <content:encoded> XML node's text content is HTML; no further processing needed.
 286             $this->content = $contentEl->textContent;
 287         } else {
 288             $descriptionEl = ActivityUtils::child($item, self::DESCRIPTION, self::RSS);
 289             if (!empty($descriptionEl)) {
 290                 // Per spec, <description> must be plaintext.
 291                 // In practice, often there's HTML... but these days good
 292                 // feeds are using <content:encoded> which is explicitly
 293                 // real HTML.
 294                 // We'll treat this following spec, and do HTML escaping
 295                 // to convert from plaintext to HTML.
 296                 $this->content = htmlspecialchars($descriptionEl->textContent);
 297             }
 298         }
 299
 300         $this->link = ActivityUtils::childContent($item, ActivityUtils::LINK, self::RSS);
 301
 302         // @fixme enclosures
 303         // @fixme thumbnails... maybe
 304
 305         $guidEl = ActivityUtils::child($item, self::GUID, self::RSS);
 306
 307         if (!empty($guidEl)) {
 308             $this->id = $guidEl->textContent;
 309
 310             if ($guidEl->hasAttribute('isPermaLink') && $guidEl->getAttribute('isPermaLink') != 'false') {
 311                 // overwrites <link>
 312                 $this->link = $this->id;
 313             }
 314         }
 315
 316         $this->objects[] = new ActivityObject($item);
 317         $this->context   = new ActivityContext($item);
 318     }
 319
 320     /**
 321      * Returns an Atom <entry> based on this activity
 322      *
 323      * @return DOMElement Atom entry
 324      */
 325     function toAtomEntry()
 326     {
 327         return null;
 328     }
 329
 330     function asString($namespace=false, $author=true)
 331     {
 332         $c = Cache::instance();
 333
 334         $str = $c->get(Cache::codeKey('activity:as-string:'.$this->id));
 335
 336         if (!empty($str)) {
 337             return $str;
 338         }
 339
 340         $xs = new XMLStringer(true);
 341
 342         if ($namespace) {
 343             $attrs = array('xmlns' => 'http://www.w3.org/2005/Atom',
 344                            'xmlns:thr' => 'http://purl.org/syndication/thread/1.0',
 345                            'xmlns:activity' => 'http://activitystrea.ms/spec/1.0/',
 346                            'xmlns:georss' => 'http://www.georss.org/georss',
 347                            'xmlns:ostatus' => 'http://ostatus.org/schema/1.0',
 348                            'xmlns:poco' => 'http://portablecontacts.net/spec/1.0',
 349                            'xmlns:media' => 'http://purl.org/syndication/atommedia',
 350                            'xmlns:statusnet' => 'http://status.net/schema/api/1/');
 351         } else {
 352             $attrs = array();
 353         }
 354
 355         $xs->elementStart('entry', $attrs);
 356
 357         if ($this->verb == ActivityVerb::POST && count($this->objects) == 1) {
 358
 359             $obj = $this->objects[0];
 360
 361             $xs->element('id', null, $obj->id);
 362             $xs->element('activity:object-type', null, $obj->type);
 363
 364             if (!empty($obj->title)) {
 365                 $xs->element('title', null, $obj->title);
 366             } else {
 367                 // XXX need a better default title
 368                 $xs->element('title', null, _('Post'));
 369             }
 370
 371             if (!empty($obj->content)) {
 372                 $xs->element('content', array('type' => 'html'), $obj->content);
 373             }
 374
 375             if (!empty($obj->summary)) {
 376                 $xs->element('summary', null, $obj->summary);
 377             }
 378
 379             if (!empty($obj->link)) {
 380                 $xs->element('link', array('rel' => 'alternate',
 381                                            'type' => 'text/html'),
 382                              $obj->link);
 383             }
 384
 385             // XXX: some object types might have other values here.
 386
 387         } else {
 388             $xs->element('id', null, $this->id);
 389             $xs->element('title', null, $this->title);
 390
 391             $xs->element('content', array('type' => 'html'), $this->content);
 392
 393             if (!empty($this->summary)) {
 394                 $xs->element('summary', null, $this->summary);
 395             }
 396
 397             if (!empty($this->link)) {
 398                 $xs->element('link', array('rel' => 'alternate',
 399                                            'type' => 'text/html'),
 400                              $this->link);
 401             }
 402
 403         }
 404
 405         $xs->element('activity:verb', null, $this->verb);
 406
 407         $published = self::iso8601Date($this->time);
 408
 409         $xs->element('published', null, $published);
 410         $xs->element('updated', null, $published);
 411
 412         if ($author) {
 413             $xs->elementStart('author');
 414             $xs->element('uri', array(), $this->actor->id);
 415             if ($this->actor->title) {
 416                 $xs->element('name', array(), $this->actor->title);
 417             }
 418             $xs->elementEnd('author');
 419             $xs->raw($this->actor->asString('activity:actor'));
 420         }
 421
 422         if ($this->verb != ActivityVerb::POST || count($this->objects) != 1) {
 423             foreach($this->objects as $object) {
 424                 $xs->raw($object->asString());
 425             }
 426         }
 427
 428         if (!empty($this->context)) {
 429
 430             if (!empty($this->context->replyToID)) {
 431                 if (!empty($this->context->replyToUrl)) {
 432                     $xs->element('thr:in-reply-to',
 433                                  array('ref' => $this->context->replyToID,
 434                                        'href' => $this->context->replyToUrl));
 435                 } else {
 436                     $xs->element('thr:in-reply-to',
 437                                  array('ref' => $this->context->replyToID));
 438                 }
 439             }
 440
 441             if (!empty($this->context->replyToUrl)) {
 442                 $xs->element('link', array('rel' => 'related',
 443                                            'href' => $this->context->replyToUrl));
 444             }
 445
 446             if (!empty($this->context->conversation)) {
 447                 $xs->element('link', array('rel' => 'ostatus:conversation',
 448                                            'href' => $this->context->conversation));
 449             }
 450
 451             foreach ($this->context->attention as $attnURI) {
 452                 $xs->element('link', array('rel' => 'ostatus:attention',
 453                                            'href' => $attnURI));
 454                 $xs->element('link', array('rel' => 'mentioned',
 455                                            'href' => $attnURI));
 456             }
 457
 458             // XXX: shoulda used ActivityVerb::SHARE
 459
 460             if (!empty($this->context->forwardID)) {
 461                 if (!empty($this->context->forwardUrl)) {
 462                     $xs->element('ostatus:forward',
 463                                  array('ref' => $this->context->forwardID,
 464                                        'href' => $this->context->forwardUrl));
 465                 } else {
 466                     $xs->element('ostatus:forward',
 467                                  array('ref' => $this->context->forwardID));
 468                 }
 469             }
 470
 471             if (!empty($this->context->location)) {
 472                 $loc = $this->context->location;
 473                 $xs->element('georss:point', null, $loc->lat . ' ' . $loc->lon);
 474             }
 475         }
 476
 477         if ($this->target) {
 478             $xs->raw($this->target->asString('activity:target'));
 479         }
 480
 481         foreach ($this->categories as $cat) {
 482             $xs->raw($cat->asString());
 483         }
 484
 485         // can be either URLs or enclosure objects
 486
 487         foreach ($this->enclosures as $enclosure) {
 488             if (is_string($enclosure)) {
 489                 $xs->element('link', array('rel' => 'enclosure',
 490                                            'href' => $enclosure));
 491             } else {
 492                 $attributes = array('rel' => 'enclosure',
 493                                     'href' => $enclosure->url,
 494                                     'type' => $enclosure->mimetype,
 495                                     'length' => $enclosure->size);
 496                 if ($enclosure->title) {
 497                     $attributes['title'] = $enclosure->title;
 498                 }
 499                 $xs->element('link', $attributes);
 500             }
 501         }
 502
 503         // Info on the source feed
 504
 505         if (!empty($this->source)) {
 506             $xs->elementStart('source');
 507
 508             $xs->element('id', null, $this->source->id);
 509             $xs->element('title', null, $this->source->title);
 510
 511             if (array_key_exists('alternate', $this->source->links)) {
 512                 $xs->element('link', array('rel' => 'alternate',
 513                                            'type' => 'text/html',
 514                                            'href' => $this->source->links['alternate']));
 515             }
 516
 517             if (array_key_exists('self', $this->source->links)) {
 518                 $xs->element('link', array('rel' => 'self',
 519                                            'type' => 'application/atom+xml',
 520                                            'href' => $this->source->links['self']));
 521             }
 522
 523             if (array_key_exists('license', $this->source->links)) {
 524                 $xs->element('link', array('rel' => 'license',
 525                                            'href' => $this->source->links['license']));
 526             }
 527
 528             if (!empty($this->source->icon)) {
 529                 $xs->element('icon', null, $this->source->icon);
 530             }
 531
 532             if (!empty($this->source->updated)) {
 533                 $xs->element('updated', null, $this->source->updated);
 534             }
 535
 536             $xs->elementEnd('source');
 537         }
 538
 539         if (!empty($this->selfLink)) {
 540             $xs->element('link', array('rel' => 'self',
 541                                        'type' => 'application/atom+xml',
 542                                        'href' => $this->selfLink));
 543         }
 544
 545         if (!empty($this->editLink)) {
 546             $xs->element('link', array('rel' => 'edit',
 547                                        'type' => 'application/atom+xml',
 548                                        'href' => $this->editLink));
 549         }
 550
 551         // For throwing in extra elements; used for statusnet:notice_info
 552
 553         foreach ($this->extra as $el) {
 554             list($tag, $attrs, $content) = $el;
 555             $xs->element($tag, $attrs, $content);
 556         }
 557
 558         $xs->elementEnd('entry');
 559
 560         $str = $xs->getString();
 561
 562         $c->set(Cache::codeKey('activity:as-string:'.$this->id), $str);
 563
 564         return $str;
 565     }
 566
 567     private function _child($element, $tag, $namespace=self::SPEC)
 568     {
 569         return ActivityUtils::child($element, $tag, $namespace);
 570     }
 571
 572     static function iso8601Date($tm)
 573     {
 574         $dateStr = date('d F Y H:i:s', $tm);
 575         $d = new DateTime($dateStr, new DateTimeZone('UTC'));
 576         $d->setTimezone(new DateTimeZone(common_timezone()));
 577         return $d->format('c');
 578     }
 579 }