Help:COAP-3180/week5

Week 5 - COAP 3180

ATTENTION: Monday week 6 class is cancelled. Replacement has to be negociated..

Topics Covered

Homework and mid-term exam

• Quick feedback

Termproject

• Each student should now have a "must-have" and "nice-to-have" list of features
• Demonstration of the Wordpress extension "Formidable"

Crashcourse on XML

• XML - The formalism
• XML - where is it used
• XSLT - XML transformations
• XPath - identify elements in a tree (used by XPath and XQuery)

Classroom activities

(1) Term project

• Must have and nice to have features
• Remark: There must an embedded "database", i.e. a data-collection / presentation module

(2) Wordpress

• Fire up MoWes and enter wordpress as admin
• Install "Formidable" if not already done so
  • Best method is to click on Plugins in the Dashboard
  • Else, use the "manual" method described by its developer.

(3) Produce XML output from an SQL query with php

• copy this code to a mowes/web/ directoty
• call it for example: mysql-to-xml.php
• configure and test

<?php

/* Made by Daniel K. Schneider, TECFA Jan 2010. This is freeware
   Will connect to a MySQL database, execute an SQL statement and
   then return the result as valid XML
 */
error_reporting(E_ALL);

// ---------------------------  Configuration section

// Fill in according to your db settings
// Make sure to keep the ; and the ""
$host       = "localhost";
$user       = "root";
$pass       = "";
$database   = "exam";

// replace by a real *.xsl file, e.g.
// $xslt_file = "exam.xsl";
$xslt_file  = FALSE; 
// If true, will output XML without XSLT
$raw        = TRUE; 

// Replace by a query that matches your database
$SQL_query = "SELECT * FROM question,response_item WHERE question.id = response_item.id_question";

// -------------------------- no changes needed below

$DB_link = mysql_connect($host, $user, $pass) or die("Could not connect to host.");
mysql_select_db($database, $DB_link) or die ("Could not find or access the database.");
$result = mysql_query ($SQL_query, $DB_link) or die ("Data not found. Your SQL query didn't work... ");

$left = "<";
$right = ">";

if ($xslt_file or $raw) {
  // we produce XML
  header("Content-type: text/xml");
  $XML = "<?xml version=\"1.0\"?>\n";
  if (!$raw) $XML .= "<?xml-stylesheet href=\"$xslt_file\" type=\"text/xsl\" ?>";
 }
 else {
   // we produce HTML. All XML tags are replaced by printable entities
   $XML = "Don't forget to create an XSLT file .... <p>";
   $XML .= "<pre>\n";
   $left = "&lt;";
   $right = "&gt;";
 }

// root node
  $XML .= $left . "result" . $right . "\n";
// rows
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {    
  $XML .= "\t" . $left. "row" . $right . "\n";  // creates either "<row>" or "&lt;row&gt;"
  $i = 0;
  // cells
  foreach ($row as $cell) {
    // Escaping illegal characters
    $cell = str_replace("&", "&amp;", $cell);
    $cell = str_replace("<", "&lt;", $cell);
    $cell = str_replace(">", "&gt;", $cell);
    $cell = str_replace("\"", "&quot;", $cell);
    $col_name = mysql_field_name($result,$i);
    // creates the "<tag>contents</tag>" representing the column, either as XML or for display in HTML
    $XML .= "\t\t" . $left . $col_name . $right . $cell . $left . "/" . $col_name . $right ."\n";
    $i++;
  }
  $XML .= "\t" . $left. "/row" . $right . "\n";
 }

  $XML .= $left . "/result" . $right . "\n";

echo $XML;
if (!$xslt_file && !$raw) echo "</pre>";

?>

(4) Edit an XML file (Wednesday)

(5) Modify an XSLT file

• Filter data with XSLT

Homework 5

Details to be announced on Wednesday ...

• Pull out data in XML format from a database
• Produce an XSLT file that will display the data (any maybe do some filtering)
• Associate the XSLT file either server-side or client side.

The instructor will provide a php file that does the extraction.

Submission Dates

• This homework is due at start of wed week 6
• Students must provide the URL (where the instructor can see the widget) in the world classroom
• Each homework counts 10% in your global evaluation. The four best homeworks will be taken into account.

Links and teaching materials

Software

• A good XML editor, e.g. XML exchanger light

Online software

• none

Teaching materials

• XML (exam topic, must know)
• DTD tutorial (understand how to use/read a DTD only)
• XSLT Tutorial - Basics (exam topic, must know)
• XPath tutorial - basics (exam topic, must know partly)
• XQuery tutorial - basics (week 6 preview, exam topic, must know)
• PHP-MySQL tutorial -basics (in particular the section about XML output)
• PHP - MySQL - XML tutorial - basics (must be able to use the code)

Teaching materials (older slides)

• http://tecfa.unige.ch/guides/te/files/xml-intro-edit.pdf
• http://tecfa.unige.ch/guides/te/files/xml-ns.pdf (optional)
• http://tecfa.unige.ch/guides/te/files/xslt-basics.pdf

Optional reading

• Donald Bourret (2005). XML and Databases, http://www.rpbourret.com/xml/XMLAndDatabases.htm
• Darshan Singh, Essential XQuery - The XML Query Language, http://www.yukonxml.com/articles/xquery/
• XQuery http://en.wikipedia.org/wiki/XQuery (Wikipedia)