SAX Example Code Page 32

Finally, we open and parse the XML file:

      # open XML file

      if (!($fp = fopen($file, "r"))) {

          die("Cannot open XML data file: $file");

      }

 

      # read and parse data

      while ($data = fread($fp, 4096)) {

The error handling section checks to see if the XML parser is not at the end of the XML file when an error occurs. If there is an error and we're not at the end of the file, then we capture and send the error code and the line where the error occurred to the browser:

          # error handling

          if (!xml_parse($xmlParser, $data, feof($fp))) {

              die(sprintf("XML error: %s at line %d",

                   xml_error_string(xml_get_error_code($xmlParser)),

                   xml_get_current_line_number($xmlParser)));

              xml_parser_free($xmlParser);

          }

      }

      # free up the parser

      xml_parser_free($xmlParser);

      ?>

    </table>

  </body>

</html>

There are a total of five error messages that can be captured. For more information, refer to: http://www.php.net/manual/en/function.xml-parse.php.

xml_parse() has three parameters – the name of the parser ($xmlParser), the data to check ($data), and an optional parameter to indicate that the last piece of data is being sent in this chuck of data. If this optional parameter is set and true then this is the last piece of data. If it is set and false then this isn't the last piece of data.

The feof() function checks to see if the pointer is at the end of the file or if there is an error. If it is at the end of the file or there is an error, then it returns true. If it isn't or there's no error, then it returns false. It is a good practice to validate the generated HTML and make sure there are no errors. Performing this validation is a good way to debug the code if you're having problems.

This figure shows the output of the above code:

SAX Example Code Page 31
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