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             // Standalone <activity:actor> elements are a holdover from older
 186             // versions of ActivityStreams. Newer feeds should have this data
 187             // integrated straight into <atom:author>.
 188
 189             $this->actor = new ActivityObject($actorEl);
 190
 191             // Cliqset has bad actor IDs (just nickname of user). We
 192             // work around it by getting the author data and using its
 193             // id instead
 194
 195             if (!preg_match('/^\w+:/', $this->actor->id)) {
 196                 $authorEl = ActivityUtils::child($entry, 'author');
 197                 if (!empty($authorEl)) {
 198                     $authorObj = new ActivityObject($authorEl);
 199                     $this->actor->id = $authorObj->id;
 200                 }
 201             }
 202         } else if ($authorEl = $this->_child($entry, self::AUTHOR, self::ATOM)) {
 203
 204             // An <atom:author> in the entry overrides any author info on
 205             // the surrounding feed.
 206             $this->actor = new ActivityObject($authorEl);
 207
 208         } else if (!empty($feed) && $authorEl = $this->_child($feed, self::AUTHOR,
 209                                                               self::ATOM)) {
 210
 211             // If there's no <atom:author> on the entry, it's safe to assume
 212             // the containing feed's authorship info applies.
 213             $this->actor = new ActivityObject($authorEl);
 214         } else if (!empty($feed) &&
 215                    $subjectEl = $this->_child($feed, self::SUBJECT)) {
 216
 217             // Feed subject is used for things like groups.
 218             // Should actually possibly not be interpreted as an actor...?
 219             $this->actor = new ActivityObject($subjectEl);
 220         }
 221
 222         $contextEl = $this->_child($entry, self::CONTEXT);
 223
 224         if (!empty($contextEl)) {
 225             $this->context = new ActivityContext($contextEl);
 226         } else {
 227             $this->context = new ActivityContext($entry);
 228         }
 229
 230         $targetEl = $this->_child($entry, self::TARGET);
 231
 232         if (!empty($targetEl)) {
 233             $this->target = new ActivityObject($targetEl);
 234         }
 235
 236         $this->summary = ActivityUtils::childContent($entry, 'summary');
 237         $this->id      = ActivityUtils::childContent($entry, 'id');
 238         $this->content = ActivityUtils::getContent($entry);
 239
 240         $catEls = $entry->getElementsByTagNameNS(self::ATOM, 'category');
 241         if ($catEls) {
 242             for ($i = 0; $i < $catEls->length; $i++) {
 243                 $catEl = $catEls->item($i);
 244                 $this->categories[] = new AtomCategory($catEl);
 245             }
 246         }
 247
 248         foreach (ActivityUtils::getLinks($entry, 'enclosure') as $link) {
 249             $this->enclosures[] = $link->getAttribute('href');
 250         }
 251
 252         // From APP. Might be useful.
 253
 254         $this->selfLink = ActivityUtils::getLink($entry, 'self', 'application/atom+xml');
 255         $this->editLink = ActivityUtils::getLink($entry, 'edit', 'application/atom+xml');
 256     }
 257
 258     function _fromRssItem($item, $channel)
 259     {
 260         $verbEl = $this->_child($item, self::VERB);
 261
 262         if (!empty($verbEl)) {
 263             $this->verb = trim($verbEl->textContent);
 264         } else {
 265             $this->verb = ActivityVerb::POST;
 266             // XXX: do other implied stuff here
 267         }
 268
 269         $pubDateEl = $this->_child($item, self::PUBDATE, self::RSS);
 270
 271         if (!empty($pubDateEl)) {
 272             $this->time = strtotime($pubDateEl->textContent);
 273         }
 274
 275         if ($authorEl = $this->_child($item, self::AUTHOR, self::RSS)) {
 276             $this->actor = ActivityObject::fromRssAuthor($authorEl);
 277         } else if ($dcCreatorEl = $this->_child($item, self::CREATOR, self::DC)) {
 278             $this->actor = ActivityObject::fromDcCreator($dcCreatorEl);
 279         } else if ($posterousEl = $this->_child($item, ActivityObject::AUTHOR, ActivityObject::POSTEROUS)) {
 280             // Special case for Posterous.com
 281             $this->actor = ActivityObject::fromPosterousAuthor($posterousEl);
 282         } else if (!empty($channel)) {
 283             $this->actor = ActivityObject::fromRssChannel($channel);
 284         } else {
 285             // No actor!
 286         }
 287
 288         $this->title = ActivityUtils::childContent($item, ActivityObject::TITLE, self::RSS);
 289
 290         $contentEl = ActivityUtils::child($item, self::ENCODED, self::CONTENTNS);
 291
 292         if (!empty($contentEl)) {
 293             // <content:encoded> XML node's text content is HTML; no further processing needed.
 294             $this->content = $contentEl->textContent;
 295         } else {
 296             $descriptionEl = ActivityUtils::child($item, self::DESCRIPTION, self::RSS);
 297             if (!empty($descriptionEl)) {
 298                 // Per spec, <description> must be plaintext.
 299                 // In practice, often there's HTML... but these days good
 300                 // feeds are using <content:encoded> which is explicitly
 301                 // real HTML.
 302                 // We'll treat this following spec, and do HTML escaping
 303                 // to convert from plaintext to HTML.
 304                 $this->content = htmlspecialchars($descriptionEl->textContent);
 305             }
 306         }
 307
 308         $this->link = ActivityUtils::childContent($item, ActivityUtils::LINK, self::RSS);
 309
 310         // @fixme enclosures
 311         // @fixme thumbnails... maybe
 312
 313         $guidEl = ActivityUtils::child($item, self::GUID, self::RSS);
 314
 315         if (!empty($guidEl)) {
 316             $this->id = $guidEl->textContent;
 317
 318             if ($guidEl->hasAttribute('isPermaLink') && $guidEl->getAttribute('isPermaLink') != 'false') {
 319                 // overwrites <link>
 320                 $this->link = $this->id;
 321             }
 322         }
 323
 324         $this->objects[] = new ActivityObject($item);
 325         $this->context   = new ActivityContext($item);
 326     }
 327
 328     /**
 329      * Returns an Atom <entry> based on this activity
 330      *
 331      * @return DOMElement Atom entry
 332      */
 333
 334     function toAtomEntry()
 335     {
 336         return null;
 337     }
 338
 339     function asString($namespace=false, $author=true, $source=false)
 340     {
 341         $xs = new XMLStringer(true);
 342         $this->outputTo($xs, $namespace, $author, $source);
 343         return $xs->getString();
 344     }
 345
 346     function outputTo($xs, $namespace=false, $author=true, $source=false)
 347     {
 348         if ($namespace) {
 349             $attrs = array('xmlns' => 'http://www.w3.org/2005/Atom',
 350                            'xmlns:thr' => 'http://purl.org/syndication/thread/1.0',
 351                            'xmlns:activity' => 'http://activitystrea.ms/spec/1.0/',
 352                            'xmlns:georss' => 'http://www.georss.org/georss',
 353                            'xmlns:ostatus' => 'http://ostatus.org/schema/1.0',
 354                            'xmlns:poco' => 'http://portablecontacts.net/spec/1.0',
 355                            'xmlns:media' => 'http://purl.org/syndication/atommedia',
 356                            'xmlns:statusnet' => 'http://status.net/schema/api/1/');
 357         } else {
 358             $attrs = array();
 359         }
 360
 361         $xs->elementStart('entry', $attrs);
 362
 363         if ($this->verb == ActivityVerb::POST && count($this->objects) == 1) {
 364
 365             $obj = $this->objects[0];
 366                         $obj->outputTo($xs, null);
 367
 368         } else {
 369             $xs->element('id', null, $this->id);
 370             $xs->element('title', null, $this->title);
 371
 372             $xs->element('content', array('type' => 'html'), $this->content);
 373
 374             if (!empty($this->summary)) {
 375                 $xs->element('summary', null, $this->summary);
 376             }
 377
 378             if (!empty($this->link)) {
 379                 $xs->element('link', array('rel' => 'alternate',
 380                                            'type' => 'text/html'),
 381                              $this->link);
 382             }
 383
 384         }
 385
 386         $xs->element('activity:verb', null, $this->verb);
 387
 388         $published = self::iso8601Date($this->time);
 389
 390         $xs->element('published', null, $published);
 391         $xs->element('updated', null, $published);
 392
 393         if ($author) {
 394             $this->actor->outputTo($xs, 'author');
 395         }
 396
 397         if ($this->verb != ActivityVerb::POST || count($this->objects) != 1) {
 398             foreach($this->objects as $object) {
 399                 $object->outputTo($xs, 'activity:object');
 400             }
 401         }
 402
 403         if (!empty($this->context)) {
 404
 405             if (!empty($this->context->replyToID)) {
 406                 if (!empty($this->context->replyToUrl)) {
 407                     $xs->element('thr:in-reply-to',
 408                                  array('ref' => $this->context->replyToID,
 409                                        'href' => $this->context->replyToUrl));
 410                 } else {
 411                     $xs->element('thr:in-reply-to',
 412                                  array('ref' => $this->context->replyToID));
 413                 }
 414             }
 415
 416             if (!empty($this->context->replyToUrl)) {
 417                 $xs->element('link', array('rel' => 'related',
 418                                            'href' => $this->context->replyToUrl));
 419             }
 420
 421             if (!empty($this->context->conversation)) {
 422                 $xs->element('link', array('rel' => 'ostatus:conversation',
 423                                            'href' => $this->context->conversation));
 424             }
 425
 426             foreach ($this->context->attention as $attnURI) {
 427                 $xs->element('link', array('rel' => 'ostatus:attention',
 428                                            'href' => $attnURI));
 429                 $xs->element('link', array('rel' => 'mentioned',
 430                                            'href' => $attnURI));
 431             }
 432
 433             // XXX: shoulda used ActivityVerb::SHARE
 434
 435             if (!empty($this->context->forwardID)) {
 436                 if (!empty($this->context->forwardUrl)) {
 437                     $xs->element('ostatus:forward',
 438                                  array('ref' => $this->context->forwardID,
 439                                        'href' => $this->context->forwardUrl));
 440                 } else {
 441                     $xs->element('ostatus:forward',
 442                                  array('ref' => $this->context->forwardID));
 443                 }
 444             }
 445
 446             if (!empty($this->context->location)) {
 447                 $loc = $this->context->location;
 448                 $xs->element('georss:point', null, $loc->lat . ' ' . $loc->lon);
 449             }
 450         }
 451
 452         if ($this->target) {
 453             $this->target->outputTo($xs, 'activity:target');
 454         }
 455
 456         foreach ($this->categories as $cat) {
 457             $cat->outputTo($xs);
 458         }
 459
 460         // can be either URLs or enclosure objects
 461
 462         foreach ($this->enclosures as $enclosure) {
 463             if (is_string($enclosure)) {
 464                 $xs->element('link', array('rel' => 'enclosure',
 465                                            'href' => $enclosure));
 466             } else {
 467                 $attributes = array('rel' => 'enclosure',
 468                                     'href' => $enclosure->url,
 469                                     'type' => $enclosure->mimetype,
 470                                     'length' => $enclosure->size);
 471                 if ($enclosure->title) {
 472                     $attributes['title'] = $enclosure->title;
 473                 }
 474                 $xs->element('link', $attributes);
 475             }
 476         }
 477
 478         // Info on the source feed
 479
 480         if ($source && !empty($this->source)) {
 481             $xs->elementStart('source');
 482
 483             $xs->element('id', null, $this->source->id);
 484             $xs->element('title', null, $this->source->title);
 485
 486             if (array_key_exists('alternate', $this->source->links)) {
 487                 $xs->element('link', array('rel' => 'alternate',
 488                                            'type' => 'text/html',
 489                                            'href' => $this->source->links['alternate']));
 490             }
 491
 492             if (array_key_exists('self', $this->source->links)) {
 493                 $xs->element('link', array('rel' => 'self',
 494                                            'type' => 'application/atom+xml',
 495                                            'href' => $this->source->links['self']));
 496             }
 497
 498             if (array_key_exists('license', $this->source->links)) {
 499                 $xs->element('link', array('rel' => 'license',
 500                                            'href' => $this->source->links['license']));
 501             }
 502
 503             if (!empty($this->source->icon)) {
 504                 $xs->element('icon', null, $this->source->icon);
 505             }
 506
 507             if (!empty($this->source->updated)) {
 508                 $xs->element('updated', null, $this->source->updated);
 509             }
 510
 511             $xs->elementEnd('source');
 512         }
 513
 514         if (!empty($this->selfLink)) {
 515             $xs->element('link', array('rel' => 'self',
 516                                        'type' => 'application/atom+xml',
 517                                        'href' => $this->selfLink));
 518         }
 519
 520         if (!empty($this->editLink)) {
 521             $xs->element('link', array('rel' => 'edit',
 522                                        'type' => 'application/atom+xml',
 523                                        'href' => $this->editLink));
 524         }
 525
 526         // For throwing in extra elements; used for statusnet:notice_info
 527
 528         foreach ($this->extra as $el) {
 529             list($tag, $attrs, $content) = $el;
 530             $xs->element($tag, $attrs, $content);
 531         }
 532
 533         $xs->elementEnd('entry');
 534
 535         return;
 536     }
 537
 538     private function _child($element, $tag, $namespace=self::SPEC)
 539     {
 540         return ActivityUtils::child($element, $tag, $namespace);
 541     }
 542
 543     static function iso8601Date($tm)
 544     {
 545         $dateStr = date('d F Y H:i:s', $tm);
 546         $d = new DateTime($dateStr, new DateTimeZone('UTC'));
 547         $d->setTimezone(new DateTimeZone(common_timezone()));
 548         return $d->format('c');
 549     }
 550 }