Lab 3 (EXPANDED)
This week you will turn your site into a real
application! The key is adding backend
server support with a database.
- Copy your Lab02 files to a new Lab03 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:
- There should be some way for the user to add new
“things” to your database. These
could be people, books, races, whatever, but there should be at least 3
different “attributes associated with each one (e.g., name, address, and
- Adding the new things should be done via your main
- There should be two ways to retrieve info from the
database from your main page. For instance, you might have an option to
search for people, then each person is clickable
for more details. Most likely,
this should be the two interactions you used for Lab02, but it can
change. You can use either XML or
text for the data, but at least one must be asynchronous.
- It should be possible to “refresh” your page, so
that if one user adds new content, a second user the already had your
page open could refresh (e.g., by querying again) and see the updated
data. This implies that if someone
queries a second time you must not just add a second list of results to
the page – it needs to change, or the old list must be deleted.
- As always, your code must be commented!
- You may use PHP or Perl. Examples given are in Perl.
REQUIREMENTS (first two you might have already):
- At least one AJAX
interaction must be based on a value that user enters in a search box.
- At least one AJAX
interaction must be based on something the user clicks, where clicking
on different elements yields different results.
- You can have more than two AJAX interactions if needed.
- When the user “inserts” new data, you must detect
if the new data is a “duplicate” with existing data (not necessarily all
the same, but for instance the same name as a record that already
exists). Your program must use
some kind of alert mechanism to warn the user that a duplicate was
detected and either replace the old data in the database or leave the
database unchanged (don’t allow more than one entry with same name).
- In your default.htm page, under “Lab3 “, include
brief user instructions (aimed at the instructor) explaining how your
interactions work and providing instructions on how to see the duplicate
detection in action.
- Suggested plan of attack (see also helpful info at
- Plan and create the database table(s) you will
- Insert some dummy data into the tables for testing.
- Get your first AJAX interaction from last week
working, where you replace the static file with some CGI program to read
from the database. At first, the
“query” can be hard-coded so that it always returns all the data from the
- Improve your interaction so that the database
results depend on what was clicked or entered in a search box.
- Get you second AJAX interaction working.
- Implement ability for user to add new data to the
- If not done already, make sure “refresh” (e.g. a
second query) doesn’t continue to show old results or an old list.
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%.
- As always, the “Error Console” in Firefox
- To connect to the database, use something like
(password to be provided):
- 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:
- Do not use
the die() function alone – the error it generates can’t be seen from your
- 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.
All of your files for Lab03 should be in a folder
called "Lab03" (without the quotes) on the Web drive.
Your main page for Lab03 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/Lab03/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 course.
The first page of the output of the W3C validator, as
run on the final version of your Lab03/index.html. This should show that your document correctly
validated, but turn it in anyway if you can’t get your page to validate.
A printout of the
source to your Lab03/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.