SAX Example Code Page 29

In the startElement function we define what HTML is associated with which element. The function startElement is called by the xml_set_element_handler function in the code. The startElement function must have three parameters:

• $parser
  This parameter refers back to the instance of the xml parser that we create
• $name
  This parameter refers to the name of the element in the XML document
• $attribs
  This parameter refers to any Attributes in the Element.

In our sample XML we have <City>Cayo Coco</City> where <City> is the start element.

By default, the value of the element is case-folded, that is, it is converted to uppercase. We change the case folding a little further on in the code. If case folding is on, then the case statement will have the name in uppercase:

case "RECORDSET":

If case folding is turned on, the parser will not match the name of the element, i.e. Recordset does not match RECORDSET. This violates the XML 1.0 specification:

      function startElement($parser, $name, $attribs) 

      {

          global $currentTag, $currentAttribs;

          $currentTag = $name;

    

          $currentAttribs = $attribs;

          # define the HTML to use for the start tag.

          switch ($name) {

          case "Recordset":

              break;

    

          case "Travelpackage":

              while (list ($key, $value) = each ($attribs)) {

                  echo("<tr><td>$key: $value</td></tr>\n");

              }

              break;

 

          case "package":

              break;

 

          default:

              echo("<tr><td>$name</td><td>\n");

              break;

          }

      }

As the parser moves through the XML document it comes across elements. For example, the parser looks at the element <Travelpackage name="a"> and matches the element name with the appropriate case in the switch block. In this instance, the data should be displayed as a row in the table with a single cell containing the name and the value of each attribute within the <Travelpackage> tag. So, <tr><td>$key: $value</td></tr> is displayed.

The case statements for <Recordset> and <Package> are empty. Therefore, nothing will be displayed when the parser sees these tags. The default case displays <tr><td>$name</td><td> where $name is the name of the current element, like <City> or <Resort>. We could create a separate case for every element in the XML document, or use one common tag for all elements.

Now let us define what the XML will look like when it is parsed and displayed by the browser. It could display a list, in which case the default case would look something like:

default:

    echo("<li>$name</li>\n");

    break;

SAX Example Code Page 28
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SAX Example Code Page 30