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