Introduce StatementGroup

Per #479 (comment)

src/Statement/StatementGroup.php

@@ -0,0 +1,95 @@
+<?php
+
+namespace Wikibase\DataModel\Statement;
+
+use InvalidArgumentException;
+use Traversable;
+use Wikibase\DataModel\Entity\PropertyId;
+use Wikibase\DataModel\PropertyIdProvider;
+
+/**
+ * List of statements with the same property id, grouped by rank.
+ *
+ * @since 4.2
+ *
+ * @license GNU GPL v2+
+ * @author Bene* < [email protected] >
+ */
+class StatementGroup implements PropertyIdProvider {
+
+	/**
+	 * @var Statement[][]
+	 */
+	private $statementsByRank = array();
+
+	/**
+	 * @var PropertyId
+	 */
+	private $propertyId;
+
+	/**
+	 * @param PropertyId|int $propertyId
+	 */
+	public function __construct( $propertyId ) {
+		if ( is_int( $propertyId ) ) {
+			$propertyId = PropertyId::newFromNumber( $propertyId );
+		}
+
+		if ( !( $propertyId instanceof PropertyId ) ) {
+			throw new InvalidArgumentException( '$propertyId must be an integer or an instance of PropertyId' );
+		}
+
+		$this->propertyId = $propertyId;
+	}
+
+	/**
+	 * @param Statement[]|Traversable $statements
+	 * @throws InvalidArgumentException
+	 */
+	public function addStatements( $statements ) {
+		if ( !is_array( $statements ) && !( $statements instanceof Traversable ) ) {
+			throw new InvalidArgumentException( '$statements must be an array or an instance of Traversable' );
+		}
+
+		foreach ( $statements as $statement ) {
+			if ( !( $statement instanceof Statement ) ) {
+				throw new InvalidArgumentException( 'Every element in $statements must be an instance of Statement' );
+			}
+
+			$this->addStatement( $statement );
+		}
+	}
+
+	/**
+	 * @param Statement $statement
+	 * @throws InvalidArgumentException
+	 */
+	public function addStatement( Statement $statement ) {
+		if ( !$statement->getPropertyId()->equals( $this->propertyId ) ) {
+			throw new InvalidArgumentException( '$statement must have the property id ' . $this->propertyId->getSerialization() );
+		}
+
+		$this->statementsByRank[$statement->getRank()][] = $statement;
+	}
+
+	/**
+	 * @see PropertyIdProvider::getPropertyId
+	 * @return PropertyId
+	 */
+	public function getPropertyId() {
+		return $this->propertyId;
+	}
+
+	/**
+	 * @param int $rank
+	 * @return Statement[]
+	 */
+	public function getByRank( $rank ) {
+		if ( isset( $this->statementsByRank[$rank] ) ) {
+			return $this->statementsByRank[$rank];
+		}
+
+		return array();
+	}
+
+}

tests/unit/Statement/StatementGroupTest.php

@@ -0,0 +1,97 @@
+<?php
+
+
+namespace Wikibase\DataModel\Tests\Statement;
+
+use DataValues\StringValue;
+use InvalidArgumentException;
+use Wikibase\DataModel\Entity\PropertyId;
+use Wikibase\DataModel\Snak\PropertyNoValueSnak;
+use Wikibase\DataModel\Snak\PropertyValueSnak;
+use Wikibase\DataModel\Statement\Statement;
+use Wikibase\DataModel\Statement\StatementGroup;
+
+/**
+ * @covers Wikibase\DataModel\Statement\StatementGroup
+ *
+ * @licence GNU GPL v2+
+ * @author Bene* < [email protected] >
+ */
+class StatementGroupTest extends \PHPUnit_Framework_TestCase {
+
+	public function testConstructor_numericId() {
+		$statementGroup = new StatementGroup( 42 );
+		$this->assertEquals( new PropertyId( 'P42' ), $statementGroup->getPropertyId() );
+	}
+
+	public function testConstructor_propertyId() {
+		$statementGroup = new StatementGroup( new PropertyId( 'P42' ) );
+		$this->assertEquals( new PropertyId( 'P42' ), $statementGroup->getPropertyId() );
+	}
+
+	/**
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testConstructor_invalidArgument() {
+		new StatementGroup( 'foo' );
+	}
+
+	public function testAddStatement_validPropertyId() {
+		$statementGroup = new StatementGroup( 42 );
+		$statement = new Statement( new PropertyNoValueSnak( 42 ) );
+		$statementGroup->addStatement( $statement );
+
+		$this->assertEquals( array( $statement ), $statementGroup->getByRank( Statement::RANK_NORMAL ) );
+	}
+
+	/**
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testAddStatement_invalidPropertyId() {
+		$statementGroup = new StatementGroup( 42 );
+		$statement = new Statement( new PropertyNoValueSnak( 12 ) );
+		$statementGroup->addStatement( $statement );
+	}
+
+	public function testAddStatements() {
+		$statementGroup = new StatementGroup( 42 );
+		$foo = new Statement( new PropertyValueSnak( 42, new StringValue( 'foo' ) ) );
+		$bar = new Statement( new PropertyValueSnak( 42, new StringValue( 'foo' ) ) );
+		$baz = new Statement( new PropertyValueSnak( 42, new StringValue( 'foo' ) ) );
+		$baz->setRank( Statement::RANK_PREFERRED );
+		$statementGroup->addStatements( array( $foo, $bar, $baz ) );
+
+		$this->assertEquals( array(), $statementGroup->getByRank( Statement::RANK_DEPRECATED ) );
+		$this->assertEquals( array( $foo, $bar ), $statementGroup->getByRank( Statement::RANK_NORMAL ) );
+		$this->assertEquals( array( $baz ), $statementGroup->getByRank( Statement::RANK_PREFERRED ) );
+	}
+
+	/**
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testAddStatements_invalidPropertyIds() {
+		$statementGroup = new StatementGroup( 42 );
+		$foo = new Statement( new PropertyValueSnak( 42, new StringValue( 'foo' ) ) );
+		$bar = new Statement( new PropertyValueSnak( 42, new StringValue( 'foo' ) ) );
+		$baz = new Statement( new PropertyValueSnak( 12, new StringValue( 'foo' ) ) );
+		$statementGroup->addStatements( array( $foo, $bar, $baz ) );
+	}
+
+	/**
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testAddStatements_noStatement() {
+		$statementGroup = new StatementGroup( 42 );
+		$statement = new Statement( new PropertyNoValueSnak( 12 ) );
+		$statementGroup->addStatements( array( $statement, 'foo' ) );
+	}
+
+	/**
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testAddStatements_noArray() {
+		$statementGroup = new StatementGroup( 42 );
+		$statementGroup->addStatements( 'foo' );
+	}
+
+}