Help:COAP-3180/week5
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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 (example is for a local and locked "play" WAMP server)
// Make sure to keep the ; and the ""
$host = "localhost";
$user = "root";
$pass = "";
$database = "exam";
// Replace by a query that matches your database
$SQL_query = "SELECT * FROM question,response_item WHERE question.id = response_item.id_question";
// Optional: add the name of XSLT file.
$xslt_file = "";
//$xslt_file = "mysql-result.xsl";
// -------------------------- 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... ");
// we produce XML
header("Content-type: text/xml");
$XML = "<?xml version=\"1.0\"?>\n";
if ($xslt_file) $XML .= "<?xml-stylesheet href=\"$xslt_file\" type=\"text/xsl\" ?>\n";
// root node
$XML .= "<result>\n";
// rows
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
$XML .= "\t<row>\n";
$i = 0;
// cells
foreach ($row as $cell) {
// Escaping illegal characters - not tested actually ;)
$cell = str_replace("&", "&", $cell);
$cell = str_replace("<", "<", $cell);
$cell = str_replace(">", ">", $cell);
$cell = str_replace("\"", """, $cell);
$col_name = mysql_field_name($result,$i);
// creates the "<tag>contents</tag>" representing the column
$XML .= "\t\t<" . $col_name . ">" . $cell . "</" . $col_name . ">\n";
$i++;
}
$XML .= "\t</row>\n";
}
$XML .= "</result>\n";
// output the whole XML string
echo $XML;
?>
(4) Edit an XML file (Wednesday)
(5) Modify an XSLT file
- Filter data with XSLT
Homework 5
- Objectives
- Pull out data in XML format from a database. If you turned in homework 3, use its tables.
- Produce an XSLT file that will display the data (any maybe do some filtering)
- Associate the XSLT file with the XML
- Steps
- Copy file http://tecfa.unige.ch/guides/xml/examples/mysql-php-xml/mysql-to-xml-raw.php.txt to a web directory of your WAMP server (or a PHP/MySQL provider). Alternatively you may copy/paste it from here. Then call it something like mysql-to-xml.php (I.e. file must end with .php!!)
- Change the values in the configuration section to make it work with one of your databases. You do not need to change anything else in this file.
- Test it
- Then save the result as test.xml (for testing purposes). In your browser, right-click on the mysql-to-xml.php and "save target as" test.xml.
- Create an XSLT file that will render test.xml in HTML. Test it with an XML editor and the test.xml file until you are pleased with the result. Remark: The XML file will be well-formed in principle, but you are likely to make XSLT syntax mistakes. Validate the XSLT file with the Exchanger light editor.
- XSLT - If things go wrong
Style-sheet error !
- Validate the style-sheet in your XML editor
- If it provides XSLT support, it will help you find the error spots
XHTML doesn’t display in Firefox !
- Firefox wants a namespace declaration in the XHMTL produced, do it (see above).
HTML doesn’t seem to be right !
- Transform the XML document within your XML editor and look at the HTML
In "Exchanger Lite", use Transform in the menu bar with the following parameters:
- Transform->Execute Advanced XSLT
- Input = current document
- XSLT = Use Processing instructions
- Output = to new file or to new document
- You also may validate the output HTML with an HTML validator !
There is various unformatted text in the output
- You forgot to write a rule for some XML element
HTML still doesn’t seem to be right !!
- Use a XSLT debugger/tracer to understand how your XSLT executes
Submission Procedure and dates
You must upload the following files to the worldclassroom:
- The *.xsl file
- The *.sql file
- The *.php file
- This homework is due at start of Wed week 6
- Each homework counts 10% in your global evaluation. The four best homeworks will be taken into account.
Evaluation
See the worldclassroom.
Tips for the homework
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)