includes/XmlTypeCheck.php

   1 <?php
   2 /**
   3  * XML syntax and type checker.
   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  */
  22
  23 class XmlTypeCheck {
  24         /**
  25          * Will be set to true or false to indicate whether the file is
  26          * well-formed XML. Note that this doesn't check schema validity.
  27          */
  28         public $wellFormed = false;
  29
  30         /**
  31          * Will be set to true if the optional element filter returned
  32          * a match at some point.
  33          */
  34         public $filterMatch = false;
  35
  36         /**
  37          * Name of the document's root element, including any namespace
  38          * as an expanded URL.
  39          */
  40         public $rootElement = '';
  41
  42         /**
  43          * @param $file string filename
  44          * @param $filterCallback callable (optional)
  45          *        Function to call to do additional custom validity checks from the
  46          *        SAX element handler event. This gives you access to the element
  47          *        namespace, name, and attributes, but not to text contents.
  48          *        Filter should return 'true' to toggle on $this->filterMatch
  49          */
  50         function __construct( $file, $filterCallback=null ) {
  51                 $this->filterCallback = $filterCallback;
  52                 $this->run( $file );
  53         }
  54
  55         /**
  56          * Get the root element. Simple accessor to $rootElement
  57          *
  58          * @return string
  59          */
  60         public function getRootElement() {
  61                 return $this->rootElement;
  62         }
  63
  64         /**
  65          * @param $fname
  66          */
  67         private function run( $fname ) {
  68                 $parser = xml_parser_create_ns( 'UTF-8' );
  69
  70                 // case folding violates XML standard, turn it off
  71                 xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
  72
  73                 xml_set_element_handler( $parser, array( $this, 'rootElementOpen' ), false );
  74
  75                 if ( file_exists( $fname ) ) {
  76                         $file = fopen( $fname, "rb" );
  77                         if ( $file ) {
  78                                 do {
  79                                         $chunk = fread( $file, 32768 );
  80                                         $ret = xml_parse( $parser, $chunk, feof( $file ) );
  81                                         if( $ret == 0 ) {
  82                                                 // XML isn't well-formed!
  83                                                 fclose( $file );
  84                                                 xml_parser_free( $parser );
  85                                                 return;
  86                                         }
  87                                 } while( !feof( $file ) );
  88
  89                                 fclose( $file );
  90                         }
  91                 }
  92
  93                 $this->wellFormed = true;
  94
  95                 xml_parser_free( $parser );
  96         }
  97
  98         /**
  99          * @param $parser
 100          * @param $name
 101          * @param $attribs
 102          */
 103         private function rootElementOpen( $parser, $name, $attribs ) {
 104                 $this->rootElement = $name;
 105
 106                 if( is_callable( $this->filterCallback ) ) {
 107                         xml_set_element_handler( $parser, array( $this, 'elementOpen' ), false );
 108                         $this->elementOpen( $parser, $name, $attribs );
 109                 } else {
 110                         // We only need the first open element
 111                         xml_set_element_handler( $parser, false, false );
 112                 }
 113         }
 114
 115         /**
 116          * @param $parser
 117          * @param $name
 118          * @param $attribs
 119          */
 120         private function elementOpen( $parser, $name, $attribs ) {
 121                 if( call_user_func( $this->filterCallback, $name, $attribs ) ) {
 122                         // Filter hit!
 123                         $this->filterMatch = true;
 124                 }
 125         }
 126 }