includes/db/ORMRow.php

   1 <?php
   2 /**
   3  * Abstract base class for representing objects that are stored in some DB table.
   4  * This is basically an ORM-like wrapper around rows in database tables that
   5  * aims to be both simple and very flexible. It is centered around an associative
   6  * array of fields and various methods to do common interaction with the database.
   7  *
   8  * Documentation inline and at https://www.mediawiki.org/wiki/Manual:ORMTable
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  *
  25  * @since 1.20
  26  *
  27  * @file ORMRow.php
  28  * @ingroup ORM
  29  *
  30  * @license GNU GPL v2 or later
  31  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  32  */
  33
  34 abstract class ORMRow implements IORMRow {
  35
  36         /**
  37          * The fields of the object.
  38          * field name (w/o prefix) => value
  39          *
  40          * @since 1.20
  41          * @var array
  42          */
  43         protected $fields = array( 'id' => null );
  44
  45         /**
  46          * @since 1.20
  47          * @var ORMTable
  48          */
  49         protected $table;
  50
  51         /**
  52          * If the object should update summaries of linked items when changed.
  53          * For example, update the course_count field in universities when a course in courses is deleted.
  54          * Settings this to false can prevent needless updating work in situations
  55          * such as deleting a university, which will then delete all it's courses.
  56          *
  57          * @since 1.20
  58          * @var bool
  59          */
  60         protected $updateSummaries = true;
  61
  62         /**
  63          * Indicates if the object is in summary mode.
  64          * This mode indicates that only summary fields got updated,
  65          * which allows for optimizations.
  66          *
  67          * @since 1.20
  68          * @var bool
  69          */
  70         protected $inSummaryMode = false;
  71
  72         /**
  73          * Constructor.
  74          *
  75          * @since 1.20
  76          *
  77          * @param IORMTable $table
  78          * @param array|null $fields
  79          * @param boolean $loadDefaults
  80          */
  81         public function __construct( IORMTable $table, $fields = null, $loadDefaults = false ) {
  82                 $this->table = $table;
  83
  84                 if ( !is_array( $fields ) ) {
  85                         $fields = array();
  86                 }
  87
  88                 if ( $loadDefaults ) {
  89                         $fields = array_merge( $this->table->getDefaults(), $fields );
  90                 }
  91
  92                 $this->setFields( $fields );
  93         }
  94
  95         /**
  96          * Load the specified fields from the database.
  97          *
  98          * @since 1.20
  99          *
 100          * @param array|null $fields
 101          * @param boolean $override
 102          * @param boolean $skipLoaded
 103          *
 104          * @return bool Success indicator
 105          */
 106         public function loadFields( $fields = null, $override = true, $skipLoaded = false ) {
 107                 if ( is_null( $this->getId() ) ) {
 108                         return false;
 109                 }
 110
 111                 if ( is_null( $fields ) ) {
 112                         $fields = array_keys( $this->table->getFields() );
 113                 }
 114
 115                 if ( $skipLoaded ) {
 116                         $fields = array_diff( $fields, array_keys( $this->fields ) );
 117                 }
 118
 119                 if ( !empty( $fields ) ) {
 120                         $result = $this->table->rawSelectRow(
 121                                 $this->table->getPrefixedFields( $fields ),
 122                                 array( $this->table->getPrefixedField( 'id' ) => $this->getId() ),
 123                                 array( 'LIMIT' => 1 )
 124                         );
 125
 126                         if ( $result !== false ) {
 127                                 $this->setFields( $this->table->getFieldsFromDBResult( $result ), $override );
 128                                 return true;
 129                         }
 130                         return false;
 131                 }
 132
 133                 return true;
 134         }
 135
 136         /**
 137          * Gets the value of a field.
 138          *
 139          * @since 1.20
 140          *
 141          * @param $name string: Field name
 142          * @param $default mixed: Default value to return when none is found
 143          * (default: null)
 144          *
 145          * @throws MWException
 146          * @return mixed
 147          */
 148         public function getField( $name, $default = null ) {
 149                 if ( $this->hasField( $name ) ) {
 150                         return $this->fields[$name];
 151                 } elseif ( !is_null( $default ) ) {
 152                         return $default;
 153                 } else {
 154                         throw new MWException( 'Attempted to get not-set field ' . $name );
 155                 }
 156         }
 157
 158         /**
 159          * Gets the value of a field but first loads it if not done so already.
 160          *
 161          * @since 1.20
 162          *
 163          * @param $name string
 164          *
 165          * @return mixed
 166          */
 167         public function loadAndGetField( $name ) {
 168                 if ( !$this->hasField( $name ) ) {
 169                         $this->loadFields( array( $name ) );
 170                 }
 171
 172                 return $this->getField( $name );
 173         }
 174
 175         /**
 176          * Remove a field.
 177          *
 178          * @since 1.20
 179          *
 180          * @param string $name
 181          */
 182         public function removeField( $name ) {
 183                 unset( $this->fields[$name] );
 184         }
 185
 186         /**
 187          * Returns the objects database id.
 188          *
 189          * @since 1.20
 190          *
 191          * @return integer|null
 192          */
 193         public function getId() {
 194                 return $this->getField( 'id' );
 195         }
 196
 197         /**
 198          * Sets the objects database id.
 199          *
 200          * @since 1.20
 201          *
 202          * @param integer|null $id
 203          */
 204         public function setId( $id ) {
 205                 $this->setField( 'id', $id );
 206         }
 207
 208         /**
 209          * Gets if a certain field is set.
 210          *
 211          * @since 1.20
 212          *
 213          * @param string $name
 214          *
 215          * @return boolean
 216          */
 217         public function hasField( $name ) {
 218                 return array_key_exists( $name, $this->fields );
 219         }
 220
 221         /**
 222          * Gets if the id field is set.
 223          *
 224          * @since 1.20
 225          *
 226          * @return boolean
 227          */
 228         public function hasIdField() {
 229                 return $this->hasField( 'id' )
 230                         && !is_null( $this->getField( 'id' ) );
 231         }
 232
 233         /**
 234          * Sets multiple fields.
 235          *
 236          * @since 1.20
 237          *
 238          * @param array $fields The fields to set
 239          * @param boolean $override Override already set fields with the provided values?
 240          */
 241         public function setFields( array $fields, $override = true ) {
 242                 foreach ( $fields as $name => $value ) {
 243                         if ( $override || !$this->hasField( $name ) ) {
 244                                 $this->setField( $name, $value );
 245                         }
 246                 }
 247         }
 248
 249         /**
 250          * Gets the fields => values to write to the table.
 251          *
 252          * @since 1.20
 253          *
 254          * @return array
 255          */
 256         protected function getWriteValues() {
 257                 $values = array();
 258
 259                 foreach ( $this->table->getFields() as $name => $type ) {
 260                         if ( array_key_exists( $name, $this->fields ) ) {
 261                                 $value = $this->fields[$name];
 262
 263                                 switch ( $type ) {
 264                                         case 'array':
 265                                                 $value = (array)$value;
 266                                                 // fall-through!
 267                                         case 'blob':
 268                                                 $value = serialize( $value );
 269                                                 // fall-through!
 270                                 }
 271
 272                                 $values[$this->table->getPrefixedField( $name )] = $value;
 273                         }
 274                 }
 275
 276                 return $values;
 277         }
 278
 279         /**
 280          * Serializes the object to an associative array which
 281          * can then easily be converted into JSON or similar.
 282          *
 283          * @since 1.20
 284          *
 285          * @param null|array $fields
 286          * @param boolean $incNullId
 287          *
 288          * @return array
 289          */
 290         public function toArray( $fields = null, $incNullId = false ) {
 291                 $data = array();
 292                 $setFields = array();
 293
 294                 if ( !is_array( $fields ) ) {
 295                         $setFields = $this->getSetFieldNames();
 296                 } else {
 297                         foreach ( $fields as $field ) {
 298                                 if ( $this->hasField( $field ) ) {
 299                                         $setFields[] = $field;
 300                                 }
 301                         }
 302                 }
 303
 304                 foreach ( $setFields as $field ) {
 305                         if ( $incNullId || $field != 'id' || $this->hasIdField() ) {
 306                                 $data[$field] = $this->getField( $field );
 307                         }
 308                 }
 309
 310                 return $data;
 311         }
 312
 313         /**
 314          * Load the default values, via getDefaults.
 315          *
 316          * @since 1.20
 317          *
 318          * @param boolean $override
 319          */
 320         public function loadDefaults( $override = true ) {
 321                 $this->setFields( $this->table->getDefaults(), $override );
 322         }
 323
 324         /**
 325          * Writes the answer to the database, either updating it
 326          * when it already exists, or inserting it when it doesn't.
 327          *
 328          * @since 1.20
 329          *
 330          * @param string|null $functionName
 331          *
 332          * @return boolean Success indicator
 333          */
 334         public function save( $functionName = null ) {
 335                 if ( $this->hasIdField() ) {
 336                         return $this->saveExisting( $functionName );
 337                 } else {
 338                         return $this->insert( $functionName );
 339                 }
 340         }
 341
 342         /**
 343          * Updates the object in the database.
 344          *
 345          * @since 1.20
 346          *
 347          * @param string|null $functionName
 348          *
 349          * @return boolean Success indicator
 350          */
 351         protected function saveExisting( $functionName = null ) {
 352                 $dbw = $this->table->getWriteDbConnection();
 353
 354                 $success = $dbw->update(
 355                         $this->table->getName(),
 356                         $this->getWriteValues(),
 357                         $this->table->getPrefixedValues( $this->getUpdateConditions() ),
 358                         is_null( $functionName ) ? __METHOD__ : $functionName
 359                 );
 360
 361                 $this->table->releaseConnection( $dbw );
 362
 363                 // DatabaseBase::update does not always return true for success as documented...
 364                 return $success !== false;
 365         }
 366
 367         /**
 368          * Returns the WHERE considtions needed to identify this object so
 369          * it can be updated.
 370          *
 371          * @since 1.20
 372          *
 373          * @return array
 374          */
 375         protected function getUpdateConditions() {
 376                 return array( 'id' => $this->getId() );
 377         }
 378
 379         /**
 380          * Inserts the object into the database.
 381          *
 382          * @since 1.20
 383          *
 384          * @param string|null $functionName
 385          * @param array|null $options
 386          *
 387          * @return boolean Success indicator
 388          */
 389         protected function insert( $functionName = null, array $options = null ) {
 390                 $dbw = $this->table->getWriteDbConnection();
 391
 392                 $success = $dbw->insert(
 393                         $this->table->getName(),
 394                         $this->getWriteValues(),
 395                         is_null( $functionName ) ? __METHOD__ : $functionName,
 396                         $options
 397                 );
 398
 399                 // DatabaseBase::insert does not always return true for success as documented...
 400                 $success = $success !== false;
 401
 402                 if ( $success ) {
 403                         $this->setField( 'id', $dbw->insertId() );
 404                 }
 405
 406                 $this->table->releaseConnection( $dbw );
 407
 408                 return $success;
 409         }
 410
 411         /**
 412          * Removes the object from the database.
 413          *
 414          * @since 1.20
 415          *
 416          * @return boolean Success indicator
 417          */
 418         public function remove() {
 419                 $this->beforeRemove();
 420
 421                 $success = $this->table->delete( array( 'id' => $this->getId() ) );
 422
 423                 // DatabaseBase::delete does not always return true for success as documented...
 424                 $success = $success !== false;
 425
 426                 if ( $success ) {
 427                         $this->onRemoved();
 428                 }
 429
 430                 return $success;
 431         }
 432
 433         /**
 434          * Gets called before an object is removed from the database.
 435          *
 436          * @since 1.20
 437          */
 438         protected function beforeRemove() {
 439                 $this->loadFields( $this->getBeforeRemoveFields(), false, true );
 440         }
 441
 442         /**
 443          * Before removal of an object happens, @see beforeRemove gets called.
 444          * This method loads the fields of which the names have been returned by this one (or all fields if null is returned).
 445          * This allows for loading info needed after removal to get rid of linked data and the like.
 446          *
 447          * @since 1.20
 448          *
 449          * @return array|null
 450          */
 451         protected function getBeforeRemoveFields() {
 452                 return array();
 453         }
 454
 455         /**
 456          * Gets called after successfull removal.
 457          * Can be overriden to get rid of linked data.
 458          *
 459          * @since 1.20
 460          */
 461         protected function onRemoved() {
 462                 $this->setField( 'id', null );
 463         }
 464
 465         /**
 466          * Return the names and values of the fields.
 467          *
 468          * @since 1.20
 469          *
 470          * @return array
 471          */
 472         public function getFields() {
 473                 return $this->fields;
 474         }
 475
 476         /**
 477          * Return the names of the fields.
 478          *
 479          * @since 1.20
 480          *
 481          * @return array
 482          */
 483         public function getSetFieldNames() {
 484                 return array_keys( $this->fields );
 485         }
 486
 487         /**
 488          * Sets the value of a field.
 489          * Strings can be provided for other types,
 490          * so this method can be called from unserialization handlers.
 491          *
 492          * @since 1.20
 493          *
 494          * @param string $name
 495          * @param mixed $value
 496          *
 497          * @throws MWException
 498          */
 499         public function setField( $name, $value ) {
 500                 $fields = $this->table->getFields();
 501
 502                 if ( array_key_exists( $name, $fields ) ) {
 503                         switch ( $fields[$name] ) {
 504                                 case 'int':
 505                                         $value = (int)$value;
 506                                         break;
 507                                 case 'float':
 508                                         $value = (float)$value;
 509                                         break;
 510                                 case 'bool':
 511                                         if ( is_string( $value ) ) {
 512                                                 $value = $value !== '0';
 513                                         } elseif ( is_int( $value ) ) {
 514                                                 $value = $value !== 0;
 515                                         }
 516                                         break;
 517                                 case 'array':
 518                                         if ( is_string( $value ) ) {
 519                                                 $value = unserialize( $value );
 520                                         }
 521
 522                                         if ( !is_array( $value ) ) {
 523                                                 $value = array();
 524                                         }
 525                                         break;
 526                                 case 'blob':
 527                                         if ( is_string( $value ) ) {
 528                                                 $value = unserialize( $value );
 529                                         }
 530                                         break;
 531                                 case 'id':
 532                                         if ( is_string( $value ) ) {
 533                                                 $value = (int)$value;
 534                                         }
 535                                         break;
 536                         }
 537
 538                         $this->fields[$name] = $value;
 539                 } else {
 540                         throw new MWException( 'Attempted to set unknown field ' . $name );
 541                 }
 542         }
 543
 544         /**
 545          * Add an amount (can be negative) to the specified field (needs to be numeric).
 546          * TODO: most off this stuff makes more sense in the table class
 547          *
 548          * @since 1.20
 549          *
 550          * @param string $field
 551          * @param integer $amount
 552          *
 553          * @return boolean Success indicator
 554          */
 555         public function addToField( $field, $amount ) {
 556                 if ( $amount == 0 ) {
 557                         return true;
 558                 }
 559
 560                 if ( !$this->hasIdField() ) {
 561                         return false;
 562                 }
 563
 564                 $absoluteAmount = abs( $amount );
 565                 $isNegative = $amount < 0;
 566
 567                 $dbw = $this->table->getWriteDbConnection();
 568
 569                 $fullField = $this->table->getPrefixedField( $field );
 570
 571                 $success = $dbw->update(
 572                         $this->table->getName(),
 573                         array( "$fullField=$fullField" . ( $isNegative ? '-' : '+' ) . $absoluteAmount ),
 574                         array( $this->table->getPrefixedField( 'id' ) => $this->getId() ),
 575                         __METHOD__
 576                 );
 577
 578                 if ( $success && $this->hasField( $field ) ) {
 579                         $this->setField( $field, $this->getField( $field ) + $amount );
 580                 }
 581
 582                 $this->table->releaseConnection( $dbw );
 583
 584                 return $success;
 585         }
 586
 587         /**
 588          * Return the names of the fields.
 589          *
 590          * @since 1.20
 591          *
 592          * @return array
 593          */
 594         public function getFieldNames() {
 595                 return array_keys( $this->table->getFields() );
 596         }
 597
 598         /**
 599          * Computes and updates the values of the summary fields.
 600          *
 601          * @since 1.20
 602          *
 603          * @param array|string|null $summaryFields
 604          */
 605         public function loadSummaryFields( $summaryFields = null ) {
 606
 607         }
 608
 609         /**
 610          * Sets the value for the @see $updateSummaries field.
 611          *
 612          * @since 1.20
 613          *
 614          * @param boolean $update
 615          */
 616         public function setUpdateSummaries( $update ) {
 617                 $this->updateSummaries = $update;
 618         }
 619
 620         /**
 621          * Sets the value for the @see $inSummaryMode field.
 622          *
 623          * @since 1.20
 624          *
 625          * @param boolean $summaryMode
 626          */
 627         public function setSummaryMode( $summaryMode ) {
 628                 $this->inSummaryMode = $summaryMode;
 629         }
 630
 631         /**
 632          * Return if any fields got changed.
 633          *
 634          * @since 1.20
 635          *
 636          * @param IORMRow $object
 637          * @param boolean|array $excludeSummaryFields
 638          *  When set to true, summary field changes are ignored.
 639          *  Can also be an array of fields to ignore.
 640          *
 641          * @return boolean
 642          */
 643         protected function fieldsChanged( IORMRow $object, $excludeSummaryFields = false ) {
 644                 $exclusionFields = array();
 645
 646                 if ( $excludeSummaryFields !== false ) {
 647                         $exclusionFields = is_array( $excludeSummaryFields ) ? $excludeSummaryFields : $this->table->getSummaryFields();
 648                 }
 649
 650                 foreach ( $this->fields as $name => $value ) {
 651                         $excluded = $excludeSummaryFields && in_array( $name, $exclusionFields );
 652
 653                         if ( !$excluded && $object->getField( $name ) !== $value ) {
 654                                 return true;
 655                         }
 656                 }
 657
 658                 return false;
 659         }
 660
 661         /**
 662          * Returns the table this IORMRow is a row in.
 663          *
 664          * @since 1.20
 665          *
 666          * @return IORMTable
 667          */
 668         public function getTable() {
 669                 return $this->table;
 670         }
 671
 672 }