8 * Copyright (c) 2009-2013 Nicholas J Humfrey. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 * 3. The name of the author 'Nicholas J Humfrey" may be used to endorse or
18 * promote products derived from this software without specific prior
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
34 * @copyright Copyright (c) 2009-2013 Nicholas J Humfrey
35 * @license http://www.opensource.org/licenses/bsd-license.php
39 * Class that represents an RDF Literal of datatype xsd:boolean
42 * @link http://www.w3.org/TR/xmlschema-2/#boolean
43 * @copyright Copyright (c) 2009-2013 Nicholas J Humfrey
44 * @license http://www.opensource.org/licenses/bsd-license.php
46 class EasyRdf_Literal_Boolean extends EasyRdf_Literal
48 /** Constructor for creating a new boolean literal
50 * If the value is not a string, then it will be converted to 'true' or 'false'.
52 * @param mixed $value The value of the literal
53 * @param string $lang Should be null (literals with a datatype can't have a language)
54 * @param string $datatype Optional datatype (default 'xsd:boolean')
55 * @return object EasyRdf_Literal_Boolean
57 public function __construct($value, $lang = null, $datatype = null)
59 if (!is_string($value)) {
60 $value = $value ? 'true' : 'false';
62 parent::__construct($value, null, $datatype);
65 /** Return the value of the literal cast to a PHP bool
67 * If the value is 'true' or '1' return true, otherwise returns false.
71 public function getValue()
73 return strtolower($this->value) === 'true' or $this->value === '1';
76 /** Return true if the value of the literal is 'true' or '1'
80 public function isTrue()
82 return strtolower($this->value) === 'true' or $this->value === '1';
85 /** Return true if the value of the literal is 'false' or '0'
89 public function isFalse()
91 return strtolower($this->value) === 'false' or $this->value === '0';