includes/XmlTypeCheck.php

   1 <?php
   2
   3 class XmlTypeCheck {
   4         /**
   5          * Will be set to true or false to indicate whether the file is
   6          * well-formed XML. Note that this doesn't check schema validity.
   7          */
   8         public $wellFormed = false;
   9
  10         /**
  11          * Will be set to true if the optional element filter returned
  12          * a match at some point.
  13          */
  14         public $filterMatch = false;
  15
  16         /**
  17          * Name of the document's root element, including any namespace
  18          * as an expanded URL.
  19          */
  20         public $rootElement = '';
  21
  22         /**
  23          * @param $file string filename
  24          * @param $filterCallback callable (optional)
  25          *        Function to call to do additional custom validity checks from the
  26          *        SAX element handler event. This gives you access to the element
  27          *        namespace, name, and attributes, but not to text contents.
  28          *        Filter should return 'true' to toggle on $this->filterMatch
  29          */
  30         function __construct( $file, $filterCallback=null ) {
  31                 $this->filterCallback = $filterCallback;
  32                 $this->run( $file );
  33         }
  34
  35         /**
  36          * Get the root element. Simple accessor to $rootElement
  37          *
  38          * @return string
  39          */
  40         public function getRootElement() {
  41                 return $this->rootElement;
  42         }
  43
  44         /**
  45          * @param $fname
  46          */
  47         private function run( $fname ) {
  48                 $parser = xml_parser_create_ns( 'UTF-8' );
  49
  50                 // case folding violates XML standard, turn it off
  51                 xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
  52
  53                 xml_set_element_handler( $parser, array( $this, 'rootElementOpen' ), false );
  54
  55                 $file = fopen( $fname, "rb" );
  56                 do {
  57                         $chunk = fread( $file, 32768 );
  58                         $ret = xml_parse( $parser, $chunk, feof( $file ) );
  59                         if( $ret == 0 ) {
  60                                 // XML isn't well-formed!
  61                                 fclose( $file );
  62                                 xml_parser_free( $parser );
  63                                 return;
  64                         }
  65                 } while( !feof( $file ) );
  66
  67                 $this->wellFormed = true;
  68
  69                 fclose( $file );
  70                 xml_parser_free( $parser );
  71         }
  72
  73         /**
  74          * @param $parser
  75          * @param $name
  76          * @param $attribs
  77          */
  78         private function rootElementOpen( $parser, $name, $attribs ) {
  79                 $this->rootElement = $name;
  80
  81                 if( is_callable( $this->filterCallback ) ) {
  82                         xml_set_element_handler( $parser, array( $this, 'elementOpen' ), false );
  83                         $this->elementOpen( $parser, $name, $attribs );
  84                 } else {
  85                         // We only need the first open element
  86                         xml_set_element_handler( $parser, false, false );
  87                 }
  88         }
  89
  90         /**
  91          * @param $parser
  92          * @param $name
  93          * @param $attribs
  94          */
  95         private function elementOpen( $parser, $name, $attribs ) {
  96                 if( call_user_func( $this->filterCallback, $name, $attribs ) ) {
  97                         // Filter hit!
  98                         $this->filterMatch = true;
  99                 }
 100         }
 101 }