Operation Contracts:

Contract CO1: purchaseTicket

Name	Details
Operation:	purchaseTicket(userID: integer, ticketID: unsigned integer, cardInfo: struct, eventID)
Cross References:	Use Cases: Purchasing a ticket.
Preconditions:	* Buyer must use the application to submit a request to purchase a ticket to the server* Buyer must have filled out the purchase form with credit card information.* Buyer must be logged in.
Postconditions	- eventID.atendees was incremented by 1- userID.account.tickets was updated with the ticket information

Contract CO2: searchFor

Name	Details
Operation:	searchFor(query: String)
Cross References:	Use Cases: Searching for a ticket.
Preconditions:	* A user must type into the search bar
Postconditions:	- A query through the database was performed - event.information query results were displayed to the user in a presentable format.

Contract CO3: generateReceipt

Name	Details
Operation:	generateReceipt(userID: integer)
Cross References:	Use Cases: Purchasing a ticket.
Preconditions:	* Buyer must be logged in.* Buyer must have purchased a ticket.
Postconditions:	- ticket.information was generated and associated with the buyer.

Contract CO4: sendReceipt

Name	Details
Operation:	sendReceipt(receiptID: integer)
Cross References:	Use Cases: Purchasing a ticket.
Preconditions:	* Buyer must be logged in. * Buyer must have purchased a ticket.
Postconditions:	- ticket.information was sent to the email of the buyer.

Contract CO5: verifyPurchase()

Name	Details
Operation:	verifyPurchase()
Cross References:	Misuse Case: Declined card
Preconditions:	* Buyer must be logged in.* Buyer must attempt to purchase a ticket.* The card was declined when making a purchase.
Postconditions:	- user.verifyPurchase() was called.- ticket.validTicket was updated if needed.