includes/db/ORMRow.php

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