includes/specials/SpecialBooksources.php

   1 <?php
   2 /**
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17  * http://www.gnu.org/copyleft/gpl.html
  18  */
  19
  20 /**
  21  * Special page outputs information on sourcing a book with a particular ISBN
  22  * The parser creates links to this page when dealing with ISBNs in wikitext
  23  *
  24  * @author Rob Church <robchur@gmail.com>
  25  * @todo Validate ISBNs using the standard check-digit method
  26  * @ingroup SpecialPage
  27  */
  28 class SpecialBookSources extends SpecialPage {
  29
  30         /**
  31          * ISBN passed to the page, if any
  32          */
  33         private $isbn = '';
  34
  35         /**
  36          * Constructor
  37          */
  38         public function __construct() {
  39                 parent::__construct( 'Booksources' );
  40         }
  41
  42         /**
  43          * Show the special page
  44          *
  45          * @param $isbn ISBN passed as a subpage parameter
  46          */
  47         public function execute( $isbn ) {
  48                 global $wgOut, $wgRequest;
  49                 $this->setHeaders();
  50                 $this->isbn = self::cleanIsbn( $isbn ? $isbn : $wgRequest->getText( 'isbn' ) );
  51                 $wgOut->addWikiMsg( 'booksources-summary' );
  52                 $wgOut->addHTML( $this->makeForm() );
  53                 if( strlen( $this->isbn ) > 0 ) {
  54                         if( !self::isValidISBN( $this->isbn ) ) {
  55                                 $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>", 'booksources-invalid-isbn' );
  56                         }
  57                         $this->showList();
  58                 }
  59         }
  60
  61         /**
  62          * Returns whether a given ISBN (10 or 13) is valid.  True indicates validity.
  63          * @param isbn ISBN passed for check
  64          */
  65         public static function isValidISBN( $isbn ) {
  66                 $isbn = self::cleanIsbn( $isbn );
  67                 $sum = 0;
  68                 $check = -1;
  69                 if( strlen( $isbn ) == 13 ) {
  70                         for( $i = 0; $i < 12; $i++ ) {
  71                                 if($i % 2 == 0) {
  72                                         $sum += $isbn{$i};
  73                                 } else {
  74                                         $sum += 3 * $isbn{$i};
  75                                 }
  76                         }
  77
  78                         $check = (10 - ($sum % 10)) % 10;
  79                         if ($check == $isbn{12}) {
  80                                 return true;
  81                         }
  82                 } elseif( strlen( $isbn ) == 10 ) {
  83                         for($i = 0; $i < 9; $i++) {
  84                                 $sum += $isbn{$i} * ($i + 1);
  85                         }
  86
  87                         $check = $sum % 11;
  88                         if($check == 10) {
  89                                 $check = "X";
  90                         }
  91                         if($check == $isbn{9}) {
  92                                 return true;
  93                         }
  94                 }
  95                 return false;
  96         }
  97
  98
  99         /**
 100          * Trim ISBN and remove characters which aren't required
 101          *
 102          * @param $isbn Unclean ISBN
 103          * @return string
 104          */
 105         private static function cleanIsbn( $isbn ) {
 106                 return trim( preg_replace( '![^0-9X]!', '', $isbn ) );
 107         }
 108
 109         /**
 110          * Generate a form to allow users to enter an ISBN
 111          *
 112          * @return string
 113          */
 114         private function makeForm() {
 115                 global $wgScript;
 116                 $title = self::getTitleFor( 'Booksources' );
 117                 $form  = '<fieldset><legend>' . wfMsgHtml( 'booksources-search-legend' ) . '</legend>';
 118                 $form .= Xml::openElement( 'form', array( 'method' => 'get', 'action' => $wgScript ) );
 119                 $form .= Xml::hidden( 'title', $title->getPrefixedText() );
 120                 $form .= '<p>' . Xml::inputLabel( wfMsg( 'booksources-isbn' ), 'isbn', 'isbn', 20, $this->isbn );
 121                 $form .= '&#160;' . Xml::submitButton( wfMsg( 'booksources-go' ) ) . '</p>';
 122                 $form .= Xml::closeElement( 'form' );
 123                 $form .= '</fieldset>';
 124                 return $form;
 125         }
 126
 127         /**
 128          * Determine where to get the list of book sources from,
 129          * format and output them
 130          *
 131          * @return string
 132          */
 133         private function showList() {
 134                 global $wgOut, $wgContLang;
 135
 136                 # Hook to allow extensions to insert additional HTML,
 137                 # e.g. for API-interacting plugins and so on
 138                 wfRunHooks( 'BookInformation', array( $this->isbn, &$wgOut ) );
 139
 140                 # Check for a local page such as Project:Book_sources and use that if available
 141                 $title = Title::makeTitleSafe( NS_PROJECT, wfMsgForContent( 'booksources' ) ); # Show list in content language
 142                 if( is_object( $title ) && $title->exists() ) {
 143                         $rev = Revision::newFromTitle( $title );
 144                         $wgOut->addWikiText( str_replace( 'MAGICNUMBER', $this->isbn, $rev->getText() ) );
 145                         return true;
 146                 }
 147
 148                 # Fall back to the defaults given in the language file
 149                 $wgOut->addWikiMsg( 'booksources-text' );
 150                 $wgOut->addHTML( '<ul>' );
 151                 $items = $wgContLang->getBookstoreList();
 152                 foreach( $items as $label => $url )
 153                         $wgOut->addHTML( $this->makeListItem( $label, $url ) );
 154                 $wgOut->addHTML( '</ul>' );
 155                 return true;
 156         }
 157
 158         /**
 159          * Format a book source list item
 160          *
 161          * @param $label Book source label
 162          * @param $url Book source URL
 163          * @return string
 164          */
 165         private function makeListItem( $label, $url ) {
 166                 $url = str_replace( '$1', $this->isbn, $url );
 167                 return '<li><a href="' . htmlspecialchars( $url ) . '" class="external">' . htmlspecialchars( $label ) . '</a></li>';
 168         }
 169 }