HW#5 --- last modified January 16 2019 00:35:22..

Solution Set.

Due date: noon Mar. 7
=========

Files to be submitted:  p40hw5file1.php (put in directory ~/public_html/hw5
======================  under Unix and also in a directory \SUBMIT
                        under NT.

HW5 Purpose: (1) To gain experience with connecting to a database in PHP
============ (2) To use hidden fields with forms. (3) To use
             cookies to maintain past sessions.

Specification:
==============
For this assignment you will complete a partially finished script that
is supposed to produce forms to allow a user to create a travel itinerary
using the airtransportation database. Here is the partially finished
script. You will need to write the function Intro($MSG), CKAirport(),
Itinerary(), SetCookies(), Connect(), FreeCursor(), Close(), Prepare($query),
FetchRow($cursor). The partially finished script contains comments as
to what these functions do. Below is a description of what the whole
script does.

The main block of the script is essentially just be a switch
statement on the value of the field State. Depending
on this value the appropriate page drawing function is called.
All forms on pages in this assignment should use the POST method.
If State is undefined then the intro page function is called
with a blank message to draw the intro page.
This page has two submit buttons (only the one that
is clicked will have it's value passed, if you want you can have
these in two forms on the same page). The title of this
page is: Travel Planner. If there had been a message it would have
been printed next in a blue h3 heading. Travel Planner is then also
printed at the top of page in a h1 heading. Beneath this should appear

Previous itinerary: [Fetch Now]

[Fetch Now] is a submit button with name State and value Fetch Now.
There should then be a horizontal rule followed by:

Departure City or Airport: [             ]

Destination City or Airport: [             ]

Departure Date: [          ]
                 YYYY-MM-DD

[Reset] [Show Flights]

This is the end of the second form of this page. The [    ]'s indicate
textfields, [Reset] resets this form, and [Show Flights] is a submit
button with name State and value Show Flights.
The airtransportation database only has flights stored in it from between
August 1-4, 2001. The airports stoed in it are LAX, BOSTON, Charle de Gaulle,
Orly, Halifax. If [Show Flights] is clicked, it calls the CKAirport() function
which first checks if the three
fields have been filled out. If not, CKAirport() returns the  the message
"Sorry, you did not give me enough  data. Please fill in the
starred fields." In the main switch the Intro function gets called with
this message. Since there was a message passed to intro it draws, each field
that was not filled in now has a * after it.
Use the OutStar function to draw the *'s.
If all fields were filled out, CKAirport() then queries the  Airport table of
the airtransportation database to see if it contains either an airport code or
a city for both the departure and destination specified. If not it returns
the message, "Sorry we do not service, name_of_city" (it does this twice if
can't match either city.) then the switch in the main menu will reprint the
intro screen. If there were two airports that match either the departure city
or destination city, it goes
to a new page which has a form that uses selection gadgets (done using the
<select> tag look at DrawSelect function) to allow the user
to specify the airport and continue
with the request. Otherwise, (and also when this latter form was filled
out) CKAirport returns("done"). This causes the main switch to call
the Flight() function which outputs a page saying, "Select a flight:" then has a
selection gadget so that the user can select a flight from among the
flights list in the Flight table in the airtransportation database
between the departure and destination airport on that day. It then has
three buttons Main Menu, Continue. Clicking Main Menu goes to
the intro page, Continue goes to a
page which lists in a selection gadget all  non-booked seats on this
flight together with whether the seat is a window or aisle and if it is
first or economy class. Flight() has already been written for you, but this is
what it does if you'd like to understand the code. The page to
select a seat is draw by the SelectSeat() function.
Again, this page has Main Menu, Previous and Continue
buttons. These works as before however, the Continue button this time
causes the Itinerary("unsaved") function to be called. It
generates a page which prints out the itinerary so far followed by three
buttons: [Main Menu], [Previous], [Save itinerary]. The first two
buttons do as before. Clicking [Save itinerary] causes SetCookies() to be
called. This function writes cookies
to the client machine with all the data of the itinerary. It then returns
to the intro page but with "Itinerary saved" printed before the
Travel Planner heading. If on the intro page the [Fetch Now] button is
clicked the Itinerary("saved") functions is called.
The cookie variable is looked at and the stored itinerary is regenerated and
displayed. If no cookie was stored it calls the Intro function
with the messafe "No previous itinerary."
followed by the rest of the intro page.

Some links
==========

1. airtransportation database schema
2. An example PHP program to list out airport table.
3. An example PERL DBI program to list out airport table.

Point Breakdown for HW5
=======================

Code documentation.....................1pt
Intro page prints as described.........1pt
The previous itinerary button works....1pt
Error handling for each
 page generated by script works
 as described..........................1pt
Specify an airport page shows up if
 needed and works as described.........1pt
Select a flight page works as
 described.............................1pt
Select a seat page works as
 described.............................1pt
Save itinerary works using cookies.....1pt

Total..................................8pts

Additional Bonus Problem: 3pts
========================

File to submit: p40hw5bon1.plx
=============== put in same places as the main assignment.
                Will discuss Monday, March 5 after class necessary
                Tk to do this.

Due date: same as HW6
=========

Specification:
==============
Rewrite the above assignment as a stand-alone (not using browser) program
using Perl/Tk and DBI.