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  * @licence 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 string $name
 142          * @param mixed $default
 143          *
 144          * @throws MWException
 145          * @return mixed
 146          */
 147         public function getField( $name, $default = null ) {
 148                 if ( $this->hasField( $name ) ) {
 149                         return $this->fields[$name];
 150                 } elseif ( !is_null( $default ) ) {
 151                         return $default;
 152                 } else {
 153                         throw new MWException( 'Attempted to get not-set field ' . $name );
 154                 }
 155         }
 156
 157         /**
 158          * Gets the value of a field but first loads it if not done so already.
 159          *
 160          * @since 1.20
 161          *
 162          * @param string$name
 163          *
 164          * @return mixed
 165          */
 166         public function loadAndGetField( $name ) {
 167                 if ( !$this->hasField( $name ) ) {
 168                         $this->loadFields( array( $name ) );
 169                 }
 170
 171                 return $this->getField( $name );
 172         }
 173
 174         /**
 175          * Remove a field.
 176          *
 177          * @since 1.20
 178          *
 179          * @param string $name
 180          */
 181         public function removeField( $name ) {
 182                 unset( $this->fields[$name] );
 183         }
 184
 185         /**
 186          * Returns the objects database id.
 187          *
 188          * @since 1.20
 189          *
 190          * @return integer|null
 191          */
 192         public function getId() {
 193                 return $this->getField( 'id' );
 194         }
 195
 196         /**
 197          * Sets the objects database id.
 198          *
 199          * @since 1.20
 200          *
 201          * @param integer|null $id
 202          */
 203         public function setId( $id ) {
 204                 $this->setField( 'id', $id );
 205         }
 206
 207         /**
 208          * Gets if a certain field is set.
 209          *
 210          * @since 1.20
 211          *
 212          * @param string $name
 213          *
 214          * @return boolean
 215          */
 216         public function hasField( $name ) {
 217                 return array_key_exists( $name, $this->fields );
 218         }
 219
 220         /**
 221          * Gets if the id field is set.
 222          *
 223          * @since 1.20
 224          *
 225          * @return boolean
 226          */
 227         public function hasIdField() {
 228                 return $this->hasField( 'id' )
 229                         && !is_null( $this->getField( 'id' ) );
 230         }
 231
 232         /**
 233          * Sets multiple fields.
 234          *
 235          * @since 1.20
 236          *
 237          * @param array $fields The fields to set
 238          * @param boolean $override Override already set fields with the provided values?
 239          */
 240         public function setFields( array $fields, $override = true ) {
 241                 foreach ( $fields as $name => $value ) {
 242                         if ( $override || !$this->hasField( $name ) ) {
 243                                 $this->setField( $name, $value );
 244                         }
 245                 }
 246         }
 247
 248         /**
 249          * Gets the fields => values to write to the table.
 250          *
 251          * @since 1.20
 252          *
 253          * @return array
 254          */
 255         protected function getWriteValues() {
 256                 $values = array();
 257
 258                 foreach ( $this->table->getFields() as $name => $type ) {
 259                         if ( array_key_exists( $name, $this->fields ) ) {
 260                                 $value = $this->fields[$name];
 261
 262                                 switch ( $type ) {
 263                                         case 'array':
 264                                                 $value = (array)$value;
 265                                         case 'blob':
 266                                                 $value = serialize( $value );
 267                                 }
 268
 269                                 $values[$this->table->getPrefixedField( $name )] = $value;
 270                         }
 271                 }
 272
 273                 return $values;
 274         }
 275
 276         /**
 277          * Serializes the object to an associative array which
 278          * can then easily be converted into JSON or similar.
 279          *
 280          * @since 1.20
 281          *
 282          * @param null|array $fields
 283          * @param boolean $incNullId
 284          *
 285          * @return array
 286          */
 287         public function toArray( $fields = null, $incNullId = false ) {
 288                 $data = array();
 289                 $setFields = array();
 290
 291                 if ( !is_array( $fields ) ) {
 292                         $setFields = $this->getSetFieldNames();
 293                 } else {
 294                         foreach ( $fields as $field ) {
 295                                 if ( $this->hasField( $field ) ) {
 296                                         $setFields[] = $field;
 297                                 }
 298                         }
 299                 }
 300
 301                 foreach ( $setFields as $field ) {
 302                         if ( $incNullId || $field != 'id' || $this->hasIdField() ) {
 303                                 $data[$field] = $this->getField( $field );
 304                         }
 305                 }
 306
 307                 return $data;
 308         }
 309
 310         /**
 311          * Load the default values, via getDefaults.
 312          *
 313          * @since 1.20
 314          *
 315          * @param boolean $override
 316          */
 317         public function loadDefaults( $override = true ) {
 318                 $this->setFields( $this->table->getDefaults(), $override );
 319         }
 320
 321         /**
 322          * Writes the answer to the database, either updating it
 323          * when it already exists, or inserting it when it doesn't.
 324          *
 325          * @since 1.20
 326          *
 327          * @param string|null $functionName
 328          *
 329          * @return boolean Success indicator
 330          */
 331         public function save( $functionName = null ) {
 332                 if ( $this->hasIdField() ) {
 333                         return $this->saveExisting( $functionName );
 334                 } else {
 335                         return $this->insert( $functionName );
 336                 }
 337         }
 338
 339         /**
 340          * Updates the object in the database.
 341          *
 342          * @since 1.20
 343          *
 344          * @param string|null $functionName
 345          *
 346          * @return boolean Success indicator
 347          */
 348         protected function saveExisting( $functionName = null ) {
 349                 $dbw = wfGetDB( DB_MASTER );
 350
 351                 $success = $dbw->update(
 352                         $this->table->getName(),
 353                         $this->getWriteValues(),
 354                         $this->table->getPrefixedValues( $this->getUpdateConditions() ),
 355                         is_null( $functionName ) ? __METHOD__ : $functionName
 356                 );
 357
 358                 // DatabaseBase::update does not always return true for success as documented...
 359                 return $success !== false;
 360         }
 361
 362         /**
 363          * Returns the WHERE considtions needed to identify this object so
 364          * it can be updated.
 365          *
 366          * @since 1.20
 367          *
 368          * @return array
 369          */
 370         protected function getUpdateConditions() {
 371                 return array( 'id' => $this->getId() );
 372         }
 373
 374         /**
 375          * Inserts the object into the database.
 376          *
 377          * @since 1.20
 378          *
 379          * @param string|null $functionName
 380          * @param array|null $options
 381          *
 382          * @return boolean Success indicator
 383          */
 384         protected function insert( $functionName = null, array $options = null ) {
 385                 $dbw = wfGetDB( DB_MASTER );
 386
 387                 $success = $dbw->insert(
 388                         $this->table->getName(),
 389                         $this->getWriteValues(),
 390                         is_null( $functionName ) ? __METHOD__ : $functionName,
 391                         is_null( $options ) ? array( 'IGNORE' ) : $options
 392                 );
 393
 394                 // DatabaseBase::insert does not always return true for success as documented...
 395                 $success = $success !== false;
 396
 397                 if ( $success ) {
 398                         $this->setField( 'id', $dbw->insertId() );
 399                 }
 400
 401                 return $success;
 402         }
 403
 404         /**
 405          * Removes the object from the database.
 406          *
 407          * @since 1.20
 408          *
 409          * @return boolean Success indicator
 410          */
 411         public function remove() {
 412                 $this->beforeRemove();
 413
 414                 $success = $this->table->delete( array( 'id' => $this->getId() ) );
 415
 416                 // DatabaseBase::delete does not always return true for success as documented...
 417                 $success = $success !== false;
 418
 419                 if ( $success ) {
 420                         $this->onRemoved();
 421                 }
 422
 423                 return $success;
 424         }
 425
 426         /**
 427          * Gets called before an object is removed from the database.
 428          *
 429          * @since 1.20
 430          */
 431         protected function beforeRemove() {
 432                 $this->loadFields( $this->getBeforeRemoveFields(), false, true );
 433         }
 434
 435         /**
 436          * Before removal of an object happens, @see beforeRemove gets called.
 437          * This method loads the fields of which the names have been returned by this one (or all fields if null is returned).
 438          * This allows for loading info needed after removal to get rid of linked data and the like.
 439          *
 440          * @since 1.20
 441          *
 442          * @return array|null
 443          */
 444         protected function getBeforeRemoveFields() {
 445                 return array();
 446         }
 447
 448         /**
 449          * Gets called after successfull removal.
 450          * Can be overriden to get rid of linked data.
 451          *
 452          * @since 1.20
 453          */
 454         protected function onRemoved() {
 455                 $this->setField( 'id', null );
 456         }
 457
 458         /**
 459          * Return the names and values of the fields.
 460          *
 461          * @since 1.20
 462          *
 463          * @return array
 464          */
 465         public function getFields() {
 466                 return $this->fields;
 467         }
 468
 469         /**
 470          * Return the names of the fields.
 471          *
 472          * @since 1.20
 473          *
 474          * @return array
 475          */
 476         public function getSetFieldNames() {
 477                 return array_keys( $this->fields );
 478         }
 479
 480         /**
 481          * Sets the value of a field.
 482          * Strings can be provided for other types,
 483          * so this method can be called from unserialization handlers.
 484          *
 485          * @since 1.20
 486          *
 487          * @param string $name
 488          * @param mixed $value
 489          *
 490          * @throws MWException
 491          */
 492         public function setField( $name, $value ) {
 493                 $fields = $this->table->getFields();
 494
 495                 if ( array_key_exists( $name, $fields ) ) {
 496                         switch ( $fields[$name] ) {
 497                                 case 'int':
 498                                         $value = (int)$value;
 499                                         break;
 500                                 case 'float':
 501                                         $value = (float)$value;
 502                                         break;
 503                                 case 'bool':
 504                                         if ( is_string( $value ) ) {
 505                                                 $value = $value !== '0';
 506                                         } elseif ( is_int( $value ) ) {
 507                                                 $value = $value !== 0;
 508                                         }
 509                                         break;
 510                                 case 'array':
 511                                         if ( is_string( $value ) ) {
 512                                                 $value = unserialize( $value );
 513                                         }
 514
 515                                         if ( !is_array( $value ) ) {
 516                                                 $value = array();
 517                                         }
 518                                         break;
 519                                 case 'blob':
 520                                         if ( is_string( $value ) ) {
 521                                                 $value = unserialize( $value );
 522                                         }
 523                                         break;
 524                                 case 'id':
 525                                         if ( is_string( $value ) ) {
 526                                                 $value = (int)$value;
 527                                         }
 528                                         break;
 529                         }
 530
 531                         $this->fields[$name] = $value;
 532                 } else {
 533                         throw new MWException( 'Attempted to set unknown field ' . $name );
 534                 }
 535         }
 536
 537         /**
 538          * Add an amount (can be negative) to the specified field (needs to be numeric).
 539          * TODO: most off this stuff makes more sense in the table class
 540          *
 541          * @since 1.20
 542          *
 543          * @param string $field
 544          * @param integer $amount
 545          *
 546          * @return boolean Success indicator
 547          */
 548         public function addToField( $field, $amount ) {
 549                 if ( $amount == 0 ) {
 550                         return true;
 551                 }
 552
 553                 if ( !$this->hasIdField() ) {
 554                         return false;
 555                 }
 556
 557                 $absoluteAmount = abs( $amount );
 558                 $isNegative = $amount < 0;
 559
 560                 $dbw = wfGetDB( DB_MASTER );
 561
 562                 $fullField = $this->table->getPrefixedField( $field );
 563
 564                 $success = $dbw->update(
 565                         $this->table->getName(),
 566                         array( "$fullField=$fullField" . ( $isNegative ? '-' : '+' ) . $absoluteAmount ),
 567                         array( $this->table->getPrefixedField( 'id' ) => $this->getId() ),
 568                         __METHOD__
 569                 );
 570
 571                 if ( $success && $this->hasField( $field ) ) {
 572                         $this->setField( $field, $this->getField( $field ) + $amount );
 573                 }
 574
 575                 return $success;
 576         }
 577
 578         /**
 579          * Return the names of the fields.
 580          *
 581          * @since 1.20
 582          *
 583          * @return array
 584          */
 585         public function getFieldNames() {
 586                 return array_keys( $this->table->getFields() );
 587         }
 588
 589         /**
 590          * Computes and updates the values of the summary fields.
 591          *
 592          * @since 1.20
 593          *
 594          * @param array|string|null $summaryFields
 595          */
 596         public function loadSummaryFields( $summaryFields = null ) {
 597
 598         }
 599
 600         /**
 601          * Sets the value for the @see $updateSummaries field.
 602          *
 603          * @since 1.20
 604          *
 605          * @param boolean $update
 606          */
 607         public function setUpdateSummaries( $update ) {
 608                 $this->updateSummaries = $update;
 609         }
 610
 611         /**
 612          * Sets the value for the @see $inSummaryMode field.
 613          *
 614          * @since 1.20
 615          *
 616          * @param boolean $summaryMode
 617          */
 618         public function setSummaryMode( $summaryMode ) {
 619                 $this->inSummaryMode = $summaryMode;
 620         }
 621
 622         /**
 623          * Return if any fields got changed.
 624          *
 625          * @since 1.20
 626          *
 627          * @param IORMRow $object
 628          * @param boolean|array $excludeSummaryFields
 629          *  When set to true, summary field changes are ignored.
 630          *  Can also be an array of fields to ignore.
 631          *
 632          * @return boolean
 633          */
 634         protected function fieldsChanged( IORMRow $object, $excludeSummaryFields = false ) {
 635                 $exclusionFields = array();
 636
 637                 if ( $excludeSummaryFields !== false ) {
 638                         $exclusionFields = is_array( $excludeSummaryFields ) ? $excludeSummaryFields : $this->table->getSummaryFields();
 639                 }
 640
 641                 foreach ( $this->fields as $name => $value ) {
 642                         $excluded = $excludeSummaryFields && in_array( $name, $exclusionFields );
 643
 644                         if ( !$excluded && $object->getField( $name ) !== $value ) {
 645                                 return true;
 646                         }
 647                 }
 648
 649                 return false;
 650         }
 651
 652         /**
 653          * Returns the table this IORMRow is a row in.
 654          *
 655          * @since 1.20
 656          *
 657          * @return IORMTable
 658          */
 659         public function getTable() {
 660                 return $this->table;
 661         }
 662
 663 }