COMP 2405 Assignment 2

Assignment 2 involves the creation of a simple single-user online parachutist's log application. The starting point for this application is the form you (hopefully) created in the last part of Assignment 1.

The assignment is to be done in Perl using the cgi-lib.pl module. A copy of this module has already been placed in your ~/public_html/cgi-bin/XXXXXX/ directory. Note that the cgi program you create will have to be executable. You can mark a program as executable using the command chmod +x myfile.cgi. Due to security constraints, your program can only be writeable by the owner (you) so you can use chmod og-w myfile.cgi to achieve this. To get you started you can work with either the Simple Content Management System, the Weight Watcher Application, or (preferably) the Blood Pressure Monitor, available on the Snippets Page.

For full marks, all Perl code should use strict and there is no need to use any module other than the cgi-lib.pl module mentioned above and the DateManip module that is already installed in the system directories. All HTML and CSS generated by your application should validate without any errors or warnings. All web pages should conform to the CRAP principles of graphic design. All input should be validated by your CGI script before it is used.

Your application has 3 modes (screens):

1. [15 marks]The summary mode shows a list of all jumps completed so far.

   This mode lists all jumps completed so far. For each jump, it shows the jump number, date, time, location, and altitude. Note that the jump number is not explicitly stored it is computed by sorting the jumps according to date and time.

   The list of jumps should be sorted by the date and time of the jump with the most recent jumps appearing first. Refer to information about the Perl sort function to learn how to do this.

   This mode also provides a mechanism for viewing the details of a particular jump, editing the details of a particular jump, or editing the details of a new jump (see requirements 2 and 3 below).

   Keep in mind that some skydivers have logged thousands of jumps, so the layout of this list should be compact, ideally with one line per jump. To make this easier to read, you are asked to use the alternating row colors pattern.

2. [15 marks] The data entry mode allows you enter the details for a single jump.

   The information associated with a jump is the information from the form you created in Part 4 of Assignment 1. However, you should deactivate the input field jumpnum as this field is derived from the ordering of the jumps (by date).

   This form should have two buttons, one labelled Accept Jump Data and the other labelled Cancel. The former causes the jump data to be stored and the latter doesn't. Both buttons cause the application to return to the summary mode.

   This form, when submitted, should check all input fields. The date, time, and location fields are mandatory. The exit altitude field is also mandatory. All other fields are optional. Any numerical field that contains a value must contain a non-negative number. If the user submits a form with invalid information, the error should be reported to them and the form should be presented to them again with all the previously submitted information included.

   You should take special care to handle the date and time fields in a particularly robust way. In particular, use the package Date::Manip to correctly handle dates like today, yesterday, last thursday and so on. Internally, you should store dates using the ISO date and time format. You should also use the format when displaying dates back to the user.

3. [15 marks] The single jump mode shows the details of a single jump.

   The information displayed in this mode should be laid out in almost the same manner as the information in the data entry mode, but it is not editable.

   This mode should also have a button labelled Edit Jump Data that takes the user to the data entry mode for this jump. This mode should also have links labelled Next Jump, Previous Jump, and Summary that do the obvious things. Be careful with the boundary cases that occur when the current jump is the most recent or the first jump in the log.

4. [10 marks] Doing this will require that you store jump data on the server. This assignment requires that you do this in a text file that has the following format.
   1. Each jump will have a jump_id that is a unique code generated for that jump when the jump is first added to the system (by adding a new jump in the summary mode).
   2. Each line of the file is of the form jump_id:fieldname:data where fieldname is either one of the fields associated with the jump, and data is the value of that field. It should be easy to edit these fields by editing your file with a text editor.

      Note that some fields (in particular those with comments) may contain multiple lines of text. To deal with this, you should escape newlines and carriage returns so that, in your data file, they are stored as a single line. When rendering them back to the screen, the data can be unescaped to restore the newlines.

   3. The use of jump_id has the nice effect that, when the user edits the information for a jump or creates a new jump, this can be handled by simply appending the new information to the end of your file.