CS 330 Class 9

1
CS 330 Class 9

• Programming plan for October 28, 2007
• Logistics
• UNIX commands
• put even your htm files on max
• option move your homepage to max
• Homework
• Debugging
• Adding a new option to pizza.htm
• Self-referring pages (not covered in text)
• Start talking about interfaces to a database

2
Homework

• guestg.htm calls guestg.php
• lt?php
• check to see if this is in response to a
  submission
• if (isset(_GET'firstName')) //arriving from a
  form submission
• echo "First Name ". _GET'firstName'. 'ltbr
  /gt'
• echo "Last Name ". _GET'lastName'. 'ltbr
  /gt'
• echo "(and so forth)"
• ?gt
• Using POST instead of GET guestp.htm
• lt?php
• check to see if this is in response to a
  submission
• if (isset(_POST'firstName')) //arriving from a
  form submission
• echo "First Name ". _POST'firstName'. 'ltbr
  /gt'
• echo "Last Name ". _POST'lastName'. 'ltbr
  /gt'
• echo "(and so forth)"

3
Homework

• POST versus GET
• GET limited in maximum length of data
• POST variables not sent in the header
• avggrd1.php
• hidden1.htm
• what's missing in the response to princess?

4
Homework Unobtrusive JavaScript

• It is the extra layer above the mark-up "what is
  this text" and
• the CSS "how should it be displayed." Javascript
  adds a new
• dimension, the "how should this element behave"
  (ref)
• document.myform.onsubmit validateform
• versus
• ltform name-"myform" onsubmit"validateform()"gt
• Other aspects
• put in a separate document
• graceful degradation (does it work with no
  JavaScript?)
• "This makes the HTML code neater, allows for an
  easier
• time updating the functionality of a page, and
  makes it seem
• like you're more sophisticated (anon.)."

5
Debugging

• If you can't open a data file, check the
  permissions
• chmod aw .
• Echo variables
• http//max.wells.edu/carol/test/avrgrd_np.php
• Comment out large sections
• http//max.wells.edu/carol/test/redirect_np.php
• Email me
• Misc can edit from SSH

6
Pizza!

• Adding a new option to pizza pizza1.htm
• calls pizza1.php and presults1.php
• what's the problem here? (new choices not
  presented to the user)
• pizza1.php
• find and increment the selected item
• item_foundfalse
• count count(options)
• for (i0 i lt count i)
• if (optionsi user_selection)
• item_noi
• item_foundtrue
• dataitem_no
• if (!item_found) //add a new option
• datacount 1
• optionscount user_selection

7
Self-Referring Pages

• So far .htm pages call .php pages.
• More common practice bundle it all in one page
  which calls
• itself and is processed differently depending on
  the call.
• pizzas.php
• //check to see if the request has variables set
  by the form
• if (isset(_GET'topping'))
• //process survey information
• drop down to the HTML survey

8
Databases and PHP

• MySQL
• freeware
• supported on UNIX and Windows
• stable but evolving
• Example Wells Premed
• users identified by name, password, role. Actions
  restricted by role
• students enter and maintain their data (password
  protected)
• advisors view student data and add comments
  (password protected)
• Example CS 105 management
• dummy account sstudent with password sstudent

9
Wells Premed Site

• Student options
• Register
• Update registration

• Advisor options
• View student data by individual, state, year, all
• Add comments

• Database tables
• tblStudent student registration data
  and password
• tblAdvisor advisor name and password
  for login
• tblComments by an advisor wrt a student

10
Wells Premed Site
11
Student Data
Entered and maintained by the student Viewed by
advisors
12
Advisor login
Validated against tblAdvisor
13
Comments Table
Advisor options