File: xmlForm.php

<?php
/*
xmlForm Class: Generate HTML forms from XML config file. HTML is generated using XSL transformations.
Version: 1.0
Copyright (C) 2002 Herman Veluwenkamp

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Copy of GNU Lesser General Public License at: http://www.gnu.org/copyleft/lesser.txt
Contact author at: hermanV@subdimension.com
*/
class xmlForm {
  /*
  Constructor initialising config file location
  */
  function xmlForm($conf) {
    $this->conf = $conf;
  }

  /*
  Validate $data using rules defined in $conf
  */
  function validate($data) {
    $this->error           = '';
    $this->validationError = FALSE; // flag validation error
    $this->currentNode     = '';    // keep track of current node
    $this->newConf         = '';    // growing XML output string
    $this->var             = '';    // keeps track of VAR name we are looking at
    $this->type            = '';    // keeps track of VAR type we are looking at
    $this->regexp          = false; // regexp belonging to current VAR
    $this->inputData       = $data; // input data to be validated against XML config

    $xmlParser = xml_parser_create();
    xml_parser_set_option($xmlParser, XML_OPTION_CASE_FOLDING, false); // preserve case
    xml_set_element_handler($xmlParser, array(&$this,"startElement"), array(&$this,"endElement"));
    xml_set_character_data_handler($xmlParser, array(&$this,"characterData"));

    if (xml_parse($xmlParser, $this->conf)) $this->conf = $this->newConf; // if ok replace with new
    else $this->error = sprintf("XML Error: %s at line %d",
                                 xml_error_string(xml_get_error_code($xmlParser)),
                                 xml_get_current_line_number($xmlParser));

    xml_parser_free($xmlParser);
    return !$this->validationError;
  }
  
  /*
  Handler when start of element is encountered
  */
  function startElement($parser, $name, $attributes) {
    $this->currentNode = $name; // keep track of current node
    switch($name) {
      case 'value': return; break; // ignore VALUE nodes
      case 'var': // save var 'NAME' and 'TYPE' attributes
        $this->var  = $attributes['name'];
        $this->type = $attributes['type'];
        break;
    }
    $attributeString = ''; // concatenate attributes;
    foreach ($attributes as $key => $value) $attributeString .= $key."=\"".$value."\" ";
    $this->newConf .= "<$name $attributeString>";
  }

  /*
  Handler when end of element is encountered
  */
  function endElement($parser, $name) {
    $this->currentNode = ''; // reset current node
    switch($name) {
      case 'value': return; break; // ignore VALUE nodes
      case 'var': // end of VAR element     
        if (!$this->isVarValid()) {
          $this->newConf .= "<validation-error/>\n";
          $this->validationError = TRUE; // flag validation error
        }
        
        $data = $this->inputData[$this->var];
        if (is_array($data)) $data = '<value>'.@implode("</value>/n<value>", $data).'</value>';
        else $data = "<value>$data</value>";
        $this->newConf .= $data."\n";
        break;
    }
    $this->newConf .= "</$name>\n";
  }

  /*
  Handler for when character data is encounered
  */
  function characterData($parser, $data) {
    if ($this->currentNode == '') return; // ignore whitespace
    if ($this->currentNode == 'value') return; // ignore VALUE nodes
    if ($this->currentNode == 'validation-regexp') $this->regexp = $data; // regular expression for validation
    $this->newConf .= $data;
  }
  
  /*
  Validate current $var
  */
  function isVarValid() {
    $type   = $this->type;
    $var    = $this->var;
    $regexp = $this->regexp;
    $data   = $this->inputData[$var];

    switch ($type) {
      case 'text':
        $test_value = $data;       
        break;
       
      case 'textarea':
        $test_value = $data;
        break;

      case 'select':
        $test_value = sizeof($data);
        break;
       
      case 'multiselect':
        $test_value = sizeof($data);
        $value = @implode(',', $data);
        break;
       
      case 'radio':
        $test_value = sizeof($data);
        break;
       
      case 'checkbox':
        $test_value = sizeof($data);
        $value = @implode(',', $data);
        break;
        
      default:
        $test_value = $data;
    }
    if (preg_match($regexp, $test_value)) return TRUE; 
    else return FAlSE;
  }
  
  /*
  Perform XSL transformation on $conf passing in $parameters
  */
  function xslTransform($xsl, $parameters) {
    $result       = '';
    $hasError     = FALSE;
    $this->error  = '';
    $this->output = '';
        
    $xh = xslt_create();
    $args = array('/_xml' => $this->conf, '/_xsl' => $xsl);
    $result = xslt_process($xh, 'arg:/_xml', 'arg:/_xsl', NULL, $args, $parameters);
    if ($result) $this->output = $result;
    else {
      $this->error = "XML Error: ".xslt_error($xh).". Code is ".xslt_errno($xh);
      $hasError = TRUE;
    }    
    xslt_free($xh);  
    return !$hasError;
  }
}
?>