includes/specials/SpecialBooksources.php

   1 <?php
   2 /**
   3  * Implements Special:Booksources
   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  * @ingroup SpecialPage
  22  */
  23
  24 /**
  25  * Special page outputs information on sourcing a book with a particular ISBN
  26  * The parser creates links to this page when dealing with ISBNs in wikitext
  27  *
  28  * @author Rob Church <robchur@gmail.com>
  29  * @todo Validate ISBNs using the standard check-digit method
  30  * @ingroup SpecialPage
  31  */
  32 class SpecialBookSources extends SpecialPage {
  33         /**
  34          * ISBN passed to the page, if any
  35          */
  36         private $isbn = '';
  37
  38         /**
  39          * Constructor
  40          */
  41         public function __construct() {
  42                 parent::__construct( 'Booksources' );
  43         }
  44
  45         /**
  46          * Show the special page
  47          *
  48          * @param string $isbn ISBN passed as a subpage parameter
  49          */
  50         public function execute( $isbn ) {
  51                 $this->setHeaders();
  52                 $this->outputHeader();
  53                 $this->isbn = self::cleanIsbn( $isbn ? $isbn : $this->getRequest()->getText( 'isbn' ) );
  54                 $this->getOutput()->addHTML( $this->makeForm() );
  55                 if ( strlen( $this->isbn ) > 0 ) {
  56                         if ( !self::isValidISBN( $this->isbn ) ) {
  57                                 $this->getOutput()->wrapWikiMsg(
  58                                         "<div class=\"error\">\n$1\n</div>",
  59                                         'booksources-invalid-isbn'
  60                                 );
  61                         }
  62                         $this->showList();
  63                 }
  64         }
  65
  66         /**
  67          * Returns whether a given ISBN (10 or 13) is valid. True indicates validity.
  68          * @param string $isbn ISBN passed for check
  69          * @return bool
  70          */
  71         public static function isValidISBN( $isbn ) {
  72                 $isbn = self::cleanIsbn( $isbn );
  73                 $sum = 0;
  74                 if ( strlen( $isbn ) == 13 ) {
  75                         for ( $i = 0; $i < 12; $i++ ) {
  76                                 if ( $i % 2 == 0 ) {
  77                                         $sum += $isbn[$i];
  78                                 } else {
  79                                         $sum += 3 * $isbn[$i];
  80                                 }
  81                         }
  82
  83                         $check = ( 10 - ( $sum % 10 ) ) % 10;
  84                         if ( $check == $isbn[12] ) {
  85                                 return true;
  86                         }
  87                 } elseif ( strlen( $isbn ) == 10 ) {
  88                         for ( $i = 0; $i < 9; $i++ ) {
  89                                 $sum += $isbn[$i] * ( $i + 1 );
  90                         }
  91
  92                         $check = $sum % 11;
  93                         if ( $check == 10 ) {
  94                                 $check = "X";
  95                         }
  96                         if ( $check == $isbn[9] ) {
  97                                 return true;
  98                         }
  99                 }
 100
 101                 return false;
 102         }
 103
 104         /**
 105          * Trim ISBN and remove characters which aren't required
 106          *
 107          * @param string $isbn Unclean ISBN
 108          * @return string
 109          */
 110         private static function cleanIsbn( $isbn ) {
 111                 return trim( preg_replace( '![^0-9X]!', '', $isbn ) );
 112         }
 113
 114         /**
 115          * Generate a form to allow users to enter an ISBN
 116          *
 117          * @return string
 118          */
 119         private function makeForm() {
 120                 $form = Html::openElement( 'fieldset' ) . "\n";
 121                 $form .= Html::element(
 122                         'legend',
 123                         array(),
 124                         $this->msg( 'booksources-search-legend' )->text()
 125                 ) . "\n";
 126                 $form .= Html::openElement( 'form', array( 'method' => 'get', 'action' => wfScript() ) ) . "\n";
 127                 $form .= Html::hidden( 'title', $this->getPageTitle()->getPrefixedText() ) . "\n";
 128                 $form .= '<p>' . Xml::inputLabel(
 129                         $this->msg( 'booksources-isbn' )->text(),
 130                         'isbn',
 131                         'isbn',
 132                         20,
 133                         $this->isbn,
 134                         array( 'autofocus' => true )
 135                 );
 136                 $form .= '&#160;' . Xml::submitButton( $this->msg( 'booksources-go' )->text() ) . "</p>\n";
 137                 $form .= Html::closeElement( 'form' ) . "\n";
 138                 $form .= Html::closeElement( 'fieldset' ) . "\n";
 139
 140                 return $form;
 141         }
 142
 143         /**
 144          * Determine where to get the list of book sources from,
 145          * format and output them
 146          *
 147          * @throws MWException
 148          * @return string
 149          */
 150         private function showList() {
 151                 global $wgContLang;
 152
 153                 # Hook to allow extensions to insert additional HTML,
 154                 # e.g. for API-interacting plugins and so on
 155                 wfRunHooks( 'BookInformation', array( $this->isbn, $this->getOutput() ) );
 156
 157                 # Check for a local page such as Project:Book_sources and use that if available
 158                 $page = $this->msg( 'booksources' )->inContentLanguage()->text();
 159                 $title = Title::makeTitleSafe( NS_PROJECT, $page ); # Show list in content language
 160                 if ( is_object( $title ) && $title->exists() ) {
 161                         $rev = Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
 162                         $content = $rev->getContent();
 163
 164                         if ( $content instanceof TextContent ) {
 165                                 //XXX: in the future, this could be stored as structured data, defining a list of book sources
 166
 167                                 $text = $content->getNativeData();
 168                                 $this->getOutput()->addWikiText( str_replace( 'MAGICNUMBER', $this->isbn, $text ) );
 169
 170                                 return true;
 171                         } else {
 172                                 throw new MWException( "Unexpected content type for book sources: " . $content->getModel() );
 173                         }
 174                 }
 175
 176                 # Fall back to the defaults given in the language file
 177                 $this->getOutput()->addWikiMsg( 'booksources-text' );
 178                 $this->getOutput()->addHTML( '<ul>' );
 179                 $items = $wgContLang->getBookstoreList();
 180                 foreach ( $items as $label => $url ) {
 181                         $this->getOutput()->addHTML( $this->makeListItem( $label, $url ) );
 182                 }
 183                 $this->getOutput()->addHTML( '</ul>' );
 184
 185                 return true;
 186         }
 187
 188         /**
 189          * Format a book source list item
 190          *
 191          * @param string $label Book source label
 192          * @param string $url Book source URL
 193          * @return string
 194          */
 195         private function makeListItem( $label, $url ) {
 196                 $url = str_replace( '$1', $this->isbn, $url );
 197
 198                 return Html::rawElement( 'li', array(),
 199                         Html::element( 'a', array( 'href' => $url, 'class' => 'external' ), $label ) );
 200         }
 201
 202         protected function getGroupName() {
 203                 return 'wiki';
 204         }
 205 }