home/omtekel/wiki/extensions/Echo/includes/Iterator/FilteredSequentialIterator.php000066600000006136151335055210024601 0ustar00add( [ $userA, $userB, $userC ] ); * * $it = new BatchRowIterator( ... ); * ... * $it = new RecursiveIteratorIterator( $it ); * $users->add( new CallbackIterator( $it, function( $row ) { * ... * return $user; * } ) ); * * foreach ( $users as $user ) { * ... * } * * By default the BatchRowIterator returns an array of rows, this class * expects a stream of user objects. To bridge that gap the * RecursiveIteratorIterator is used to flatten and the CallbackIterator * is used to transform each database $row into a User object. * * @todo name? */ class FilteredSequentialIterator implements IteratorAggregate { /** * @var Iterator[] */ protected $iterators = []; /** * @var callable[] */ protected $filters = []; /** * @param Iterator|IteratorAggregate|array $users */ public function add( $users ) { if ( is_array( $users ) ) { $it = new ArrayIterator( $users ); } elseif ( $users instanceof Iterator ) { $it = $users; } elseif ( $users instanceof IteratorAggregate ) { $it = $users->getIterator(); } else { throw new InvalidArgumentException( 'Expected array, Iterator or IteratorAggregate but received:' . ( is_object( $users ) ? get_class( $users ) : gettype( $users ) ) ); } $this->iterators[] = $it; } /** * @param callable $callable */ public function addFilter( $callable ) { $this->filters[] = $callable; } /** * Satisfies IteratorAggregate interface * * @return Iterator */ public function getIterator(): Iterator { $it = $this->createIterator(); if ( $this->filters ) { $it = new CallbackFilterIterator( $it, $this->createFilter() ); } return $it; } /** * @return Iterator */ protected function createIterator() { switch ( count( $this->iterators ) ) { case 0: return new EmptyIterator; case 1: return reset( $this->iterators ); default: return new RecursiveIteratorIterator( new MultipleIterator( $this->iterators ) ); } } /** * @return callable */ protected function createFilter() { switch ( count( $this->filters ) ) { case 0: return static function () { return true; }; case 1: return reset( $this->filters ); default: $filters = $this->filters; return static function ( $user ) use ( $filters ) { foreach ( $filters as $filter ) { if ( !call_user_func( $filter, $user ) ) { return false; } } return true; }; } } }