Introduce StringParser and StringNormalizer

Bug:T104874

Author: daniel

src/ValueParsers/Normalizers/NullStringNormalizer.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace ValueParsers\Normalizers;
+
+use InvalidArgumentException;
+
+/**
+ * Null implementation of StringNormalizer.
+ *
+ * @license GPL 2+
+ * @author Daniel Kinzler
+ */
+class NullStringNormalizer implements StringNormalizer {
+
+	/**
+	 * @param string $value the value to normalize
+	 *
+	 * @return string the normalized value
+	 */
+	public function normalize( $value ) {
+		if ( !is_string( $value ) ) {
+			throw new InvalidArgumentException( 'Parameter $value must be a string' );
+		}
+
+		return $value;
+	}
+
+}

src/ValueParsers/Normalizers/StringNormalizer.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace ValueParsers\Normalizers;
+
+use InvalidArgumentException;
+
+/**
+ * Interface for string normalization
+ *
+ * @license GPL 2+
+ * @author Daniel Kinzler
+ */
+interface StringNormalizer {
+
+	/**
+	 * @param string $value the value to normalize
+	 *
+	 * @return string the normalized value
+	 *
+	 * @throws InvalidArgumentException if $value is not a string
+	 */
+	public function normalize( $value );
+
+}

src/ValueParsers/StringParser.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace ValueParsers;
+
+use InvalidArgumentException;
+use DataValues\StringValue;
+use ValueParsers\Normalizers\NullStringNormalizer;
+use ValueParsers\Normalizers\StringNormalizer;
+
+/**
+ * Implementation of the ValueParser interface for StringValues.
+ *
+ * @since 0.2.4
+ *
+ * @licence GNU GPL v2+
+ * @author Daniel Kinzler
+ */
+class StringParser implements ValueParser {
+
+	/**
+	 * @var StringNormalizer
+	 */
+	private $normalizer;
+
+	/**
+	 * @param StringNormalizer $normalizer
+	 */
+	public function __construct( StringNormalizer $normalizer = null ) {
+		if ( $normalizer === null ) {
+			$normalizer = new NullStringNormalizer();
+		}
+
+		$this->normalizer = $normalizer;
+	}
+
+	/**
+	 * @see ValueParser::parse
+	 *
+	 * @param string $value
+	 *
+	 * @return StringValue
+	 *
+	 * @throws InvalidArgumentException if $value is not a string
+	 */
+	public function parse( $value ) {
+		if ( !is_string( $value ) ) {
+			throw new InvalidArgumentException( 'Parameter $value must be a string' );
+		}
+
+		$value = $this->normalizer->normalize( $value );
+		return new StringValue( $value );
+	}
+
+}

tests/ValueParsers/StringParserTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace ValueParsers\Test;
+
+use DataValues\DataValue;
+use DataValues\StringValue;
+use ValueParsers\StringParser;
+
+/**
+ * Unit test StringParser class.
+ *
+ * @covers StringParser
+ *
+ * @since 0.1
+ *
+ * @group ValueParsers
+ * @group DataValueExtensions
+ *
+ * @licence GNU GPL v2+
+ * @author Daniel Kinzler
+ */
+class StringParserTest extends \PHPUnit_Framework_TestCase {
+
+	public function provideParse() {
+		$normalizer = $this->getMock( 'ValueParsers\Normalizers\StringNormalizer' );
+		$normalizer->expects( $this->once() )
+			->method( 'normalize' )
+			->will( $this->returnCallback( function( $value ) {
+				return strtolower( trim( $value ) );
+			} ) );
+
+		return array(
+			'simple' => array( 'hello world', null, new StringValue( 'hello world' ) ),
+			'normalize' => array( '  Hello World  ', $normalizer, new StringValue( 'hello world' ) ),
+		);
+	}
+
+	/**
+	 * @dataProvider provideParse
+	 */
+	public function testParse( $input, $normalizer, DataValue $expected ) {
+		$parser = new StringParser( $normalizer );
+		$value = $parser->parse( $input );
+
+		$this->assertInstanceOf( 'DataValues\StringValue', $value );
+		$this->assertEquals( $expected->toArray(), $value->toArray() );
+	}
+
+	public function provideParse_InvalidArgumentException() {
+		return array(
+			'null' => array( null ),
+			'array' => array( array() ),
+			'int' => array( 7 ),
+		);
+	}
+
+	/**
+	 * @dataProvider provideParse_InvalidArgumentException
+	 */
+	public function testParse_InvalidArgumentException( $input ) {
+		$this->setExpectedException( 'InvalidArgumentException' );
+
+		$parser = new StringParser();
+		$parser->parse( $input );
+	}
+
+}