Two Wheel Philanthropy And Beyond

1
Two Wheel Philanthropy And Beyond

• Practical uses for PHP

2
Two Wheel Philanthropy

• The Hard Lessons
• Action-equals-whaa?
• How does this server thingy work?
• Solutions
• Do this and print that!
• Host base this!
• Money Issues
• What do I need? (Linkpoint, merchant accounts,
  security certificates)
• How do I do that stuff? (Linkpoint XML sending
  and responding)
• The Big Shabanga-Bang
• How it works (our end).
• How it works (their end).
• Now, Sherman, what did we learn?
• More about encapsulation (encapsul-wha-tion?)
• Globals and security.

3
The hard lessons Action-equals-whaa?

• Our menu was controlled by a form, and we planned
  on separating the files by the different screens.
  
• Issue only one action can be given to a form,
  but until we enter information into the menu, we
  dont know which file to go to.

4
The Hard Lessons How Does This Server Thingy
Work?

• Assumption 1 We can use globals, right? (By the
  way, whats a global?)
• Assumption 2 Isnt PHP just a big program
  attached to Apache?
• Assumption 3 Cant we just session_start and
  go?

5
Do this and print that!

• Print functions display a page requiring
  information with a tag of where they are coming
  from.
• Do functions process the information and move
  on to the next print function.
• Other functions are for use within these.
• We have one BIG file to work with.

6
Host Base This !

• Well store a variable containing our host base
  URL and add the server variable from there.
• Well explicitly state where we want our sessions
  stored.
• Well deal with globals by declaring everything
  as global (not the best option).

7
Money Issues

• What do I need?
• Merchant Account (a place to put your money, not
  a matress)
• Security certificate (a reason for people to
  trust you to take their money)
• A service provider (to transfer money from their
  hands to yours)

• How do I get that?
• Merchant Accounts Apply for them through banks
  and such.
• Security Certificates Provide proof of business
  to a security company (Thawte).
• Program using an API of a company which has
  access to bank networks (Linkpoint, in our case).

8
The Big Shabanga-Bang How it works on our end.

• All users are stored in an SQL table (their
  passwords have been encrypted to protect the
  innocent).
• All transactions are stored in an SQL table (and
  are tagged with a random ID so PHP can tell the
  difference between them).
• All events are stored in an SQL table (with any
  notes, the time, date, and location, and price
  attached).

9
The Big Shabanga-Bang How it works on their
(Linkpoints) end.

• We collect the credit card and cost data.
• We produce an XML string according to Linkpoints
  specifications.
• Show the code
• We receive a response in XML indicating the
  success or failure of the transaction, and order
  number, and a message.
• Show the documentation
• We store this data in a table, noting the
  servers response and only the last 4 digit of
  the credit card number.

10
Now, Sherman, what did we learn? More about
encapsulation (encapsul-wha-tion?)

• Encapsulation- keeping tasks apart from each
  other so that we can change algorithms without
  changing the larger program.
• Using PHP include files helps solve for this
  problem.
• Show the code (duh)
• Not using forms as flow control allows us to
  split the tasks into different files.
• Yep, show the code again.

11
Now, Sherman, what did we learn? Globals and
Security

• Globalizing variables means they came from
  anywhere.
• The reason we had to declare each variable global
  was because PHP was running with a safety
  protocol.
• Show the dang code
• This opens up doors for people to trick the
  server. We can solve that by explicitly stating
  where the globals are supposed to come from.
• Okay, last time, show the code.