includes/title/TitleValue.php

   1 <?php
   2 /**
   3  * Representation of a page title within %MediaWiki.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @license GPL 2+
  22  * @author Daniel Kinzler
  23  */
  24 use Wikimedia\Assert\Assert;
  25
  26 /**
  27  * Represents a page (or page fragment) title within %MediaWiki.
  28  *
  29  * @note In contrast to Title, this is designed to be a plain value object. That is,
  30  * it is immutable, does not use global state, and causes no side effects.
  31  *
  32  * @note TitleValue represents the title of a local page (or fragment of a page).
  33  * It does not represent a link, and does not support interwiki prefixes etc.
  34  *
  35  * @see https://www.mediawiki.org/wiki/Requests_for_comment/TitleValue
  36  * @since 1.23
  37  */
  38 class TitleValue implements LinkTarget {
  39         /**
  40          * @var int
  41          */
  42         protected $namespace;
  43
  44         /**
  45          * @var string
  46          */
  47         protected $dbkey;
  48
  49         /**
  50          * @var string
  51          */
  52         protected $fragment;
  53
  54         /**
  55          * Constructs a TitleValue.
  56          *
  57          * @note TitleValue expects a valid DB key; typically, a TitleValue is constructed either
  58          * from a database entry, or by a TitleParser. We could apply "some" normalization here,
  59          * such as substituting spaces by underscores, but that would encourage the use of
  60          * un-normalized text when constructing TitleValues. For constructing a TitleValue from
  61          * user input or external sources, use a TitleParser.
  62          *
  63          * @param int $namespace The namespace ID. This is not validated.
  64          * @param string $dbkey The page title in valid DBkey form. No normalization is applied.
  65          * @param string $fragment The fragment title. Use '' to represent the whole page.
  66          *   No validation or normalization is applied.
  67          *
  68          * @throws InvalidArgumentException
  69          */
  70         public function __construct( $namespace, $dbkey, $fragment = '' ) {
  71                 Assert::parameterType( 'integer', $namespace, '$namespace' );
  72                 Assert::parameterType( 'string', $dbkey, '$dbkey' );
  73                 Assert::parameterType( 'string', $fragment, '$fragment' );
  74
  75                 // Sanity check, no full validation or normalization applied here!
  76                 Assert::parameter( !preg_match( '/^_|[ \r\n\t]|_$/', $dbkey ), '$dbkey', 'invalid DB key' );
  77                 Assert::parameter( $dbkey !== '', '$dbkey', 'should not be empty' );
  78
  79                 $this->namespace = $namespace;
  80                 $this->dbkey = $dbkey;
  81                 $this->fragment = $fragment;
  82         }
  83
  84         /**
  85          * @return int
  86          */
  87         public function getNamespace() {
  88                 return $this->namespace;
  89         }
  90
  91         /**
  92          * @return string
  93          */
  94         public function getFragment() {
  95                 return $this->fragment;
  96         }
  97
  98         /**
  99          * @since 1.27
 100          * @return bool
 101          */
 102         public function hasFragment() {
 103                 return $this->fragment !== '';
 104         }
 105
 106         /**
 107          * Returns the title's DB key, as supplied to the constructor,
 108          * without namespace prefix or fragment.
 109          *
 110          * @return string
 111          */
 112         public function getDBkey() {
 113                 return $this->dbkey;
 114         }
 115
 116         /**
 117          * Returns the title in text form,
 118          * without namespace prefix or fragment.
 119          *
 120          * This is computed from the DB key by replacing any underscores with spaces.
 121          *
 122          * @note To get a title string that includes the namespace and/or fragment,
 123          *       use a TitleFormatter.
 124          *
 125          * @return string
 126          */
 127         public function getText() {
 128                 return str_replace( '_', ' ', $this->getDBkey() );
 129         }
 130
 131         /**
 132          * Creates a new TitleValue for a different fragment of the same page.
 133          *
 134          * @param string $fragment The fragment name, or "" for the entire page.
 135          *
 136          * @return TitleValue
 137          */
 138         public function createFragmentTitle( $fragment ) {
 139                 return new TitleValue( $this->namespace, $this->dbkey, $fragment );
 140         }
 141
 142         /**
 143          * Returns a string representation of the title, for logging. This is purely informative
 144          * and must not be used programmatically. Use the appropriate TitleFormatter to generate
 145          * the correct string representation for a given use.
 146          *
 147          * @return string
 148          */
 149         public function __toString() {
 150                 $name = $this->namespace . ':' . $this->dbkey;
 151
 152                 if ( $this->fragment !== '' ) {
 153                         $name .= '#' . $this->fragment;
 154                 }
 155
 156                 return $name;
 157         }
 158 }