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, $source=false)
 331     {
 332         $xs = new XMLStringer(true);
 333
 334         if ($namespace) {
 335             $attrs = array('xmlns' => 'http://www.w3.org/2005/Atom',
 336                            'xmlns:thr' => 'http://purl.org/syndication/thread/1.0',
 337                            'xmlns:activity' => 'http://activitystrea.ms/spec/1.0/',
 338                            'xmlns:georss' => 'http://www.georss.org/georss',
 339                            'xmlns:ostatus' => 'http://ostatus.org/schema/1.0',
 340                            'xmlns:poco' => 'http://portablecontacts.net/spec/1.0',
 341                            'xmlns:media' => 'http://purl.org/syndication/atommedia',
 342                            'xmlns:statusnet' => 'http://status.net/schema/api/1/');
 343         } else {
 344             $attrs = array();
 345         }
 346
 347         $xs->elementStart('entry', $attrs);
 348
 349         if ($this->verb == ActivityVerb::POST && count($this->objects) == 1) {
 350
 351             $obj = $this->objects[0];
 352                         $obj->outputTo($xs, null);
 353
 354         } else {
 355             $xs->element('id', null, $this->id);
 356             $xs->element('title', null, $this->title);
 357
 358             $xs->element('content', array('type' => 'html'), $this->content);
 359
 360             if (!empty($this->summary)) {
 361                 $xs->element('summary', null, $this->summary);
 362             }
 363
 364             if (!empty($this->link)) {
 365                 $xs->element('link', array('rel' => 'alternate',
 366                                            'type' => 'text/html'),
 367                              $this->link);
 368             }
 369
 370         }
 371
 372         $xs->element('activity:verb', null, $this->verb);
 373
 374         $published = self::iso8601Date($this->time);
 375
 376         $xs->element('published', null, $published);
 377         $xs->element('updated', null, $published);
 378
 379         if ($author) {
 380             $this->actor->outputTo($xs, 'author');
 381         }
 382
 383         if ($this->verb != ActivityVerb::POST || count($this->objects) != 1) {
 384             foreach($this->objects as $object) {
 385                 $object->outputTo($xs, 'activity:object');
 386             }
 387         }
 388
 389         if (!empty($this->context)) {
 390
 391             if (!empty($this->context->replyToID)) {
 392                 if (!empty($this->context->replyToUrl)) {
 393                     $xs->element('thr:in-reply-to',
 394                                  array('ref' => $this->context->replyToID,
 395                                        'href' => $this->context->replyToUrl));
 396                 } else {
 397                     $xs->element('thr:in-reply-to',
 398                                  array('ref' => $this->context->replyToID));
 399                 }
 400             }
 401
 402             if (!empty($this->context->replyToUrl)) {
 403                 $xs->element('link', array('rel' => 'related',
 404                                            'href' => $this->context->replyToUrl));
 405             }
 406
 407             if (!empty($this->context->conversation)) {
 408                 $xs->element('link', array('rel' => 'ostatus:conversation',
 409                                            'href' => $this->context->conversation));
 410             }
 411
 412             foreach ($this->context->attention as $attnURI) {
 413                 $xs->element('link', array('rel' => 'ostatus:attention',
 414                                            'href' => $attnURI));
 415                 $xs->element('link', array('rel' => 'mentioned',
 416                                            'href' => $attnURI));
 417             }
 418
 419             // XXX: shoulda used ActivityVerb::SHARE
 420
 421             if (!empty($this->context->forwardID)) {
 422                 if (!empty($this->context->forwardUrl)) {
 423                     $xs->element('ostatus:forward',
 424                                  array('ref' => $this->context->forwardID,
 425                                        'href' => $this->context->forwardUrl));
 426                 } else {
 427                     $xs->element('ostatus:forward',
 428                                  array('ref' => $this->context->forwardID));
 429                 }
 430             }
 431
 432             if (!empty($this->context->location)) {
 433                 $loc = $this->context->location;
 434                 $xs->element('georss:point', null, $loc->lat . ' ' . $loc->lon);
 435             }
 436         }
 437
 438         if ($this->target) {
 439             $this->target->outputTo($xs, 'activity:target');
 440         }
 441
 442         foreach ($this->categories as $cat) {
 443             $xs->raw($cat->asString());
 444         }
 445
 446         // can be either URLs or enclosure objects
 447
 448         foreach ($this->enclosures as $enclosure) {
 449             if (is_string($enclosure)) {
 450                 $xs->element('link', array('rel' => 'enclosure',
 451                                            'href' => $enclosure));
 452             } else {
 453                 $attributes = array('rel' => 'enclosure',
 454                                     'href' => $enclosure->url,
 455                                     'type' => $enclosure->mimetype,
 456                                     'length' => $enclosure->size);
 457                 if ($enclosure->title) {
 458                     $attributes['title'] = $enclosure->title;
 459                 }
 460                 $xs->element('link', $attributes);
 461             }
 462         }
 463
 464         // Info on the source feed
 465
 466         if ($source && !empty($this->source)) {
 467             $xs->elementStart('source');
 468
 469             $xs->element('id', null, $this->source->id);
 470             $xs->element('title', null, $this->source->title);
 471
 472             if (array_key_exists('alternate', $this->source->links)) {
 473                 $xs->element('link', array('rel' => 'alternate',
 474                                            'type' => 'text/html',
 475                                            'href' => $this->source->links['alternate']));
 476             }
 477
 478             if (array_key_exists('self', $this->source->links)) {
 479                 $xs->element('link', array('rel' => 'self',
 480                                            'type' => 'application/atom+xml',
 481                                            'href' => $this->source->links['self']));
 482             }
 483
 484             if (array_key_exists('license', $this->source->links)) {
 485                 $xs->element('link', array('rel' => 'license',
 486                                            'href' => $this->source->links['license']));
 487             }
 488
 489             if (!empty($this->source->icon)) {
 490                 $xs->element('icon', null, $this->source->icon);
 491             }
 492
 493             if (!empty($this->source->updated)) {
 494                 $xs->element('updated', null, $this->source->updated);
 495             }
 496
 497             $xs->elementEnd('source');
 498         }
 499
 500         if (!empty($this->selfLink)) {
 501             $xs->element('link', array('rel' => 'self',
 502                                        'type' => 'application/atom+xml',
 503                                        'href' => $this->selfLink));
 504         }
 505
 506         if (!empty($this->editLink)) {
 507             $xs->element('link', array('rel' => 'edit',
 508                                        'type' => 'application/atom+xml',
 509                                        'href' => $this->editLink));
 510         }
 511
 512         // For throwing in extra elements; used for statusnet:notice_info
 513
 514         foreach ($this->extra as $el) {
 515             list($tag, $attrs, $content) = $el;
 516             $xs->element($tag, $attrs, $content);
 517         }
 518
 519         $xs->elementEnd('entry');
 520
 521         $str = $xs->getString();
 522
 523         return $str;
 524     }
 525
 526     private function _child($element, $tag, $namespace=self::SPEC)
 527     {
 528         return ActivityUtils::child($element, $tag, $namespace);
 529     }
 530
 531     static function iso8601Date($tm)
 532     {
 533         $dateStr = date('d F Y H:i:s', $tm);
 534         $d = new DateTime($dateStr, new DateTimeZone('UTC'));
 535         $d->setTimezone(new DateTimeZone(common_timezone()));
 536         return $d->format('c');
 537     }
 538 }