This week we learned how to use XSLT to leverage XML data in
your web applications. In this lab, you
will use this knowledge to manipulate XML that you extract from your database.
In future labs, you will then use XSLT to exploit other kinds of XML.
- Copy your Lab04 files (or Lab05, if you continued
your theme in Lab05) to a new Lab06 directory. Your main file should still
be called index.html
Here is what you what you want to have when you are
finished. Suggested plan of attach for
getting there is below (read it before
- Deadline for
waivers: If you think that a particular detail of this lab should be
modified for you, because you can achieve the same educational objective
in a different way that works better with your theme, you must request a
waiver, via email, before the end
of the lab period when this lab is started. State clearly why an
exception should be made and what you propose instead. You can talk to the instructor first,
but it must be finalized via email.
Firefox will sometimes cache old versions of the files you use
(especially your sample XML and your XSL files). If things aren’t working right, try
this: Tools->Clear Recent
History. Select “Everything” for
time range. Click to open the
details (if necessary) then select just “Cache” and click “Clear
Now”. This is likely to happen to
you, so make note of this issue!!!
Everything from previous labs should still work.
Per your feedback, this will NOT be required – you just need enough
working to demonstrate the functionality described below. Note that this will include the ability
to insert things into your database from your web page.
- There should be a button or something to
click or interact with such that when you click the following
- You use AJAX, which invokes a Perl(PHP okay)
script to query your DB. Synchronous AJAX is okay.
- The Perl returns a XML document (see details
below. You do not actually
save this file, just use “print” from Perl). Namespaces are not required
for this XML (but you can use if you like).
- You transform that XML with XSLT (see details
- You display part of the transformed XML in your
- All of this should happen within your original
index.html (e.g. the URL up top should not change)
- The details of the XML produced by your DB are up
to you. It should however at a minimum contain:
- Results for at least 3 distinct “things” (e.g.
people, products, events) (including all items from your DB is okay too)
- Contain at least 2 distinct attributes “about”
- Adding new results to the DB (using your existing
functionality) should cause the XML result to change (e.g., if you add a
new person, that person should appear in the XML produced).
- The details of the XSLT transformation are up to
you. It should however at a
- Do some re-orderings (e.g. not display things in
exactly the same order as the XML file)
- Insert some HTML markup
- Contains results for at least 3 distinct “things”
- Show at least 2 distinct attributes “about” each
- For testing and grading purposes, you must make
(and keep around) two test files. You must keep this up to date if you
change your XML later!
- test1.xml – sample XML in the same format that
your Perl program produces.
- test2.xml – identical to test1.xml, except it has
the line in it that causes the browser to transform it with your XSL
file before displaying the results.
- As always, your code must be commented!
- On your default.htm page, provide some instructions
for a user (e.g. the instructor) on how to use your site. This should be specific to this lab –
e.g. how can I see that your site meets the requirements for this lab?
For instance, what exactly to click, what to enter, etc. Don’t assume
that the user will have any idea what movies, people, things, etc. your
system knows about.
- Suggested plan of attack (see also helpful info at
- Do NOT
follow the requirements above in order. Instead…
- First create the dummy XML file (test1.xml) that
approximates what you WANT to produce from your database. You do not
have to have namespaces in this file.
- Verify that test1.xml is valid by loading it in a
browser. A complaint about namespaces is okay, but it should be rendered
as valid XML.
- Create your XSLT file. Suggestion: start with the
“Example 0.5” XSL from the online example page.
- COPY test1.xml to test2.xml. Now test your XSLT file by
adding the appropriate line to your test2.xml XML file (not test1.xml)
and loading it in a browser.
test1.xml), apply the XSLT to it, then insert some of the result in your
page. Note: test2.xml will not work here because of the processing
instruction that you added to it!
- Once all that works, then write the Perl code to
actually produce real XML based on querying your DB. Test this script
alone via the browser! (you want to ensure a.) the script runs b.) it
produces valid XML)
generated XML from the Perl script (instead of using the static XML).
- Make sure that the user can add content to the
database and have that content show up in the results of the transformed
- Important:: go back and check that
- test1.xml and test2.xml have identical content
(only differ in a processing instruction)
- test1.xml and test2.xml match the XML format
produced by your Perl program
- test1.xml renders as valid XML in the browser
- test2.xml shows the transformed result (e.g.
changed by XSLT) when loaded in the browser
Ensure your page works with Firefox. Having it work on
IE is encouraged but not required.
Ensure all your pages validate and that you have met
NOTE: all HTML files must validate as XHTML without errors
for full credit. The penalty for a file that does not validate is 10%.
- See the plan of attack above!
- General debug strategy:
- First, run Perl from the command line and make sure
it works (see below). Include
actual arguments so you can see it’s really working.
- Second, run Perl via the webserver
directly, e.g. something like
- Finally, try it all from HTML via the browser. If this doesn’t work
- Look first at the Error console!
- Use window.alert() to
see what is happening. In
particular, check what URL you are actually using to invoke Perl.
- Did I mention looking at the Error console?
- As always, the “Error Console” in Firefox is
- Perl is easier to debug via the windows command line.
You should first check for syntax errors by just “checking” the file:
–c -w myquery.pl
Once that works run it for real:
If needed, you can provide CGI arguments like this:
–w myquery.pl “query=dogs&type=2”
- On the command line, database errors will usually
appear automatically. From the
browser, they won’t – instead insert this as a debug:
- CREATE TABLE comments
(USER_NAME VARCHAR(20), TIMESTAMP DATETIME, COMMENT MEDIUMTEXT, PAGE
- INSERT INTO comments
(USER_NAME, TIMESTAMP, COMMENT, PAGE) VALUES ('Jamie', '2006-09-27
11:30:00', 'hi', 2);
- CREATE TABLE topics
(TOPIC VARCHAR(20), OWNER VARCHAR(20));
- INSERT INTO topics
(TOPIC, OWNER) VALUES ('Cars', ‘Jamie’);
- Note: ID is
automatically created with the table, no need to specify it.
- Do not use
the die() function alone – the error it generates can’t be seen from your
All of your files for Lab06 should be in a folder
called "Lab06" (without the quotes) on the Web drive.
Your main page for Lab06 should be called
"index.html" (without the quotes) and placed inside the folder Lab01.
Your instructor will assume that your web pages are
viewable at http://www.mXXXXXX.it452.cs.usna.edu/Lab06/index.html
where XXXXXX is your alpha number. You should check that this URL is viewable
and that everything works correctly from a computer where somebody else is
logged in. If you've goofed and linked to a file on your X drive, this will
help you catch it!
All files must be complete and saved to your Web drive
before you submit the hardcopy of your assignment. Do NOT modify your files
after you have submitted your assignment.
Turn in the following hardcopy on or before the due
date, stapled together in the following order (coversheet on top):
A completed assignment coversheet. Your comments will help us improve the
The first page of the output of the W3C validator, as run on the final version of your
Lab06/index.html. This should show that your
document correctly validated, but turn it in anyway if you can’t get your page
A printout of the
source to your Lab06/index.html file (not the rendered page that you
normally see with Internet Explorer/Firefox).
Truncated lines are not acceptable – use Crimson Editor vice Notepad if
needed for printing. You could also
paste into Microsoft Word etc. if needed.
does the transformation and insertion is acceptable if you wish.
Printout of your Perl/PHP file that generates XML.
Printout of sample
XML generated by your script. Use the browser to invoke the script with
dummy arguments to make this happen.
Printout of your XSL file