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 $isbn ISBN passed as a subpage parameter
  50          */
  51         public function execute( $isbn ) {
  52                 global $wgOut, $wgRequest;
  53                 $this->setHeaders();
  54                 $this->isbn = self::cleanIsbn( $isbn ? $isbn : $wgRequest->getText( 'isbn' ) );
  55                 $wgOut->addWikiMsg( 'booksources-summary' );
  56                 $wgOut->addHTML( $this->makeForm() );
  57                 if( strlen( $this->isbn ) > 0 ) {
  58                         if( !self::isValidISBN( $this->isbn ) ) {
  59                                 $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>", 'booksources-invalid-isbn' );
  60                         }
  61                         $this->showList();
  62                 }
  63         }
  64
  65         /**
  66          * Returns whether a given ISBN (10 or 13) is valid.  True indicates validity.
  67          * @param isbn ISBN passed for check
  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                 return false;
  99         }
 100
 101         /**
 102          * Trim ISBN and remove characters which aren't required
 103          *
 104          * @param $isbn Unclean ISBN
 105          * @return string
 106          */
 107         private static function cleanIsbn( $isbn ) {
 108                 return trim( preg_replace( '![^0-9X]!', '', $isbn ) );
 109         }
 110
 111         /**
 112          * Generate a form to allow users to enter an ISBN
 113          *
 114          * @return string
 115          */
 116         private function makeForm() {
 117                 global $wgScript;
 118                 $title = self::getTitleFor( 'Booksources' );
 119                 $form  = '<fieldset><legend>' . wfMsgHtml( 'booksources-search-legend' ) . '</legend>';
 120                 $form .= Xml::openElement( 'form', array( 'method' => 'get', 'action' => $wgScript ) );
 121                 $form .= Html::hidden( 'title', $title->getPrefixedText() );
 122                 $form .= '<p>' . Xml::inputLabel( wfMsg( 'booksources-isbn' ), 'isbn', 'isbn', 20, $this->isbn );
 123                 $form .= '&#160;' . Xml::submitButton( wfMsg( 'booksources-go' ) ) . '</p>';
 124                 $form .= Xml::closeElement( 'form' );
 125                 $form .= '</fieldset>';
 126                 return $form;
 127         }
 128
 129         /**
 130          * Determine where to get the list of book sources from,
 131          * format and output them
 132          *
 133          * @return string
 134          */
 135         private function showList() {
 136                 global $wgOut, $wgContLang;
 137
 138                 # Hook to allow extensions to insert additional HTML,
 139                 # e.g. for API-interacting plugins and so on
 140                 wfRunHooks( 'BookInformation', array( $this->isbn, &$wgOut ) );
 141
 142                 # Check for a local page such as Project:Book_sources and use that if available
 143                 $title = Title::makeTitleSafe( NS_PROJECT, wfMsgForContent( 'booksources' ) ); # Show list in content language
 144                 if( is_object( $title ) && $title->exists() ) {
 145                         $rev = Revision::newFromTitle( $title );
 146                         $wgOut->addWikiText( str_replace( 'MAGICNUMBER', $this->isbn, $rev->getText() ) );
 147                         return true;
 148                 }
 149
 150                 # Fall back to the defaults given in the language file
 151                 $wgOut->addWikiMsg( 'booksources-text' );
 152                 $wgOut->addHTML( '<ul>' );
 153                 $items = $wgContLang->getBookstoreList();
 154                 foreach( $items as $label => $url )
 155                         $wgOut->addHTML( $this->makeListItem( $label, $url ) );
 156                 $wgOut->addHTML( '</ul>' );
 157                 return true;
 158         }
 159
 160         /**
 161          * Format a book source list item
 162          *
 163          * @param $label Book source label
 164          * @param $url Book source URL
 165          * @return string
 166          */
 167         private function makeListItem( $label, $url ) {
 168                 $url = str_replace( '$1', $this->isbn, $url );
 169                 return '<li><a href="' . htmlspecialchars( $url ) . '" class="external">' . htmlspecialchars( $label ) . '</a></li>';
 170         }
 171 }