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 MediaWiki\Linker\LinkTarget;
  25 use Wikimedia\Assert\Assert;
  26
  27 /**
  28  * Represents a page (or page fragment) title within %MediaWiki.
  29  *
  30  * @note In contrast to Title, this is designed to be a plain value object. That is,
  31  * it is immutable, does not use global state, and causes no side effects.
  32  *
  33  * @note TitleValue represents the title of a local page (or fragment of a page).
  34  * It does not represent a link, and does not support interwiki prefixes etc.
  35  *
  36  * @see https://www.mediawiki.org/wiki/Requests_for_comment/TitleValue
  37  * @since 1.23
  38  */
  39 class TitleValue implements LinkTarget {
  40         /**
  41          * @var int
  42          */
  43         protected $namespace;
  44
  45         /**
  46          * @var string
  47          */
  48         protected $dbkey;
  49
  50         /**
  51          * @var string
  52          */
  53         protected $fragment;
  54
  55         /**
  56          * Constructs a TitleValue.
  57          *
  58          * @note TitleValue expects a valid DB key; typically, a TitleValue is constructed either
  59          * from a database entry, or by a TitleParser. We could apply "some" normalization here,
  60          * such as substituting spaces by underscores, but that would encourage the use of
  61          * un-normalized text when constructing TitleValues. For constructing a TitleValue from
  62          * user input or external sources, use a TitleParser.
  63          *
  64          * @param int $namespace The namespace ID. This is not validated.
  65          * @param string $dbkey The page title in valid DBkey form. No normalization is applied.
  66          * @param string $fragment The fragment title. Use '' to represent the whole page.
  67          *   No validation or normalization is applied.
  68          *
  69          * @throws InvalidArgumentException
  70          */
  71         public function __construct( $namespace, $dbkey, $fragment = '' ) {
  72                 Assert::parameterType( 'integer', $namespace, '$namespace' );
  73                 Assert::parameterType( 'string', $dbkey, '$dbkey' );
  74                 Assert::parameterType( 'string', $fragment, '$fragment' );
  75
  76                 // Sanity check, no full validation or normalization applied here!
  77                 Assert::parameter( !preg_match( '/^_|[ \r\n\t]|_$/', $dbkey ), '$dbkey', 'invalid DB key' );
  78                 Assert::parameter( $dbkey !== '', '$dbkey', 'should not be empty' );
  79
  80                 $this->namespace = $namespace;
  81                 $this->dbkey = $dbkey;
  82                 $this->fragment = $fragment;
  83         }
  84
  85         /**
  86          * @return int
  87          */
  88         public function getNamespace() {
  89                 return $this->namespace;
  90         }
  91
  92         /**
  93          * @return string
  94          */
  95         public function getFragment() {
  96                 return $this->fragment;
  97         }
  98
  99         /**
 100          * @since 1.27
 101          * @return bool
 102          */
 103         public function hasFragment() {
 104                 return $this->fragment !== '';
 105         }
 106
 107         /**
 108          * Returns the title's DB key, as supplied to the constructor,
 109          * without namespace prefix or fragment.
 110          *
 111          * @return string
 112          */
 113         public function getDBkey() {
 114                 return $this->dbkey;
 115         }
 116
 117         /**
 118          * Returns the title in text form,
 119          * without namespace prefix or fragment.
 120          *
 121          * This is computed from the DB key by replacing any underscores with spaces.
 122          *
 123          * @note To get a title string that includes the namespace and/or fragment,
 124          *       use a TitleFormatter.
 125          *
 126          * @return string
 127          */
 128         public function getText() {
 129                 return str_replace( '_', ' ', $this->getDBkey() );
 130         }
 131
 132         /**
 133          * Creates a new TitleValue for a different fragment of the same page.
 134          *
 135          * @since 1.27
 136          * @param string $fragment The fragment name, or "" for the entire page.
 137          *
 138          * @return TitleValue
 139          */
 140         public function createFragmentTarget( $fragment ) {
 141                 return new TitleValue( $this->namespace, $this->dbkey, $fragment );
 142         }
 143
 144         /**
 145          * Returns a string representation of the title, for logging. This is purely informative
 146          * and must not be used programmatically. Use the appropriate TitleFormatter to generate
 147          * the correct string representation for a given use.
 148          *
 149          * @return string
 150          */
 151         public function __toString() {
 152                 $name = $this->namespace . ':' . $this->dbkey;
 153
 154                 if ( $this->fragment !== '' ) {
 155                         $name .= '#' . $this->fragment;
 156                 }
 157
 158                 return $name;
 159         }
 160 }