Network Programming Wikiclass | Tutorial / Parse XML documents with PHP

Overview: In this tutorial, you will study how to use PHP to do event-based parsing of a XML documents.

Activity One: Install XAMPP as a Web server in your PC

Go to apache friends - xampp for windows.
Install the XAMPP for Windows as instructed.
Start the xAMPP.
In your browser, enter the address http://localhost/ or http://127.0.0.1/ to check if the Apache Web server is working.

Activity Two: Create a XML document

Create a folder named xml-tut in the document root of the Web server (i.e. C:/xampp/htdocs/xml-tut)
Create the following simple XML document and save it as xml-fruit.xml.

<?xml version="1.0"?>

<fruits>

  <fruit>Apple</fruit>

  <fruit>Pear</fruit>

  <fruit>Peach</fruit>

  <fruit>Plum</fruit>

  <fruit>Cherry</fruit>

  <fruit>Blackberry</fruit>

  <fruit>Strawberry</fruit>

  <fruit>Blueberry</fruit>

  <fruit>Papaya</fruit>

  <fruit>Lemon</fruit>

</fruits>

[Get Code]

Activity Three: Make a PHP program to parse the XML document

Create the following PHP program and save it as parse-xml-1.php in the same folder you placed xml-fruit.xml.

      $file = "xml-fruit.xml";

      function contents($parser, $data){
        echo $data;
      }

      function startTag($parser, $data){
        if($data=='FRUITS') echo "<ol>";
        if($data=='FRUIT') echo "<li>";
      }

      function endTag($parser, $data){
        if($data=='FRUITS') echo "</ol>";
        if($data=='FRUIT') echo "</li>";
      }

      $xml_parser = xml_parser_create();

      xml_set_element_handler($xml_parser, "startTag", "endTag");

      xml_set_character_data_handler($xml_parser, "contents");

      $fp = fopen($file, "r");

      $data = fread($fp, 80000);

      if(!(xml_parse($xml_parser, $data, feof($fp)))){
        die("Error on line " . xml_get_current_line_number($xml_parser));
      }

      xml_parser_free($xml_parser);

      fclose($fp);

Use your browser to execute the PHP program by the URL: localhost/xml/parse-xml-1.php

(Q1) Identify the PHP statements for the following functions/operations

      01) Define the function that will be called when a start tag is reached.
      02) Define the function that will be called when an end tag is reached.
      03) Define the function that will be called when a data is reached.
      04) Create the parser
      05) Set the start and end tag handlers 
      06) Set the data handler 
      07) Open the XML file 
      08) Read the XML file 
      09) Parse the XML data 
      10) Destroy the parser 
      11) Close the XML file

Task Four: Parse a XML Sitemap documen

Write a PHP program that can parse a XML Sitemap and output a HTML that displays all the links like the following.

      <html>
        <head>
          <title>Parse XML Sitemap</title>
        </head>
        <body>
          <h1>Web pages indexed by the Search Engines</h1>
          <ol>
            <li><a href="a">a</a></li>
            <li><a href="b">b</a></li>
            <li><a href="c">c</a></li>
          </ol>
        </body>
      </html>

The XML Sitemap for your testing will be provided.