Dinner Club Explanation

dinner_club_explanation.markdown

Dinner Club Explanation

Assignment Task

The program was built to keep track of a dinner club's events. Specifically, it stores and displays club history, as well as members and total member costs during the history of the Dinner Club.

Classes

Three classes were used to accomplish the Dinner Club assignment: CheckSplitter, ClubEvent, and DinnerClub.

CheckSplitter Class

The CheckSplitter class was created to split the costs of a given meal. It requires three parameters to split the costs of the meal:

• Total cost of the meal as an integer
• Tip percentage as an integer or float
• Number of people as an integer

ClubEvent Class

The ClubEvent cost was created to gather and store information about a specific event that the Dinner Club holds.

ClubEvent Instance Variables

• total_cost - Integer of the cost of the meal given by user
• tip_percentage - Integer or float given by user
• people - Array of members who attended the event given by user
• date - String given by user
• location - String given by user
• who_paid - String given by user
• per_person - Float calculated from a method
• total_cost_single_pay - Float calculated from a method
• attendees_hash - Hash created from a method. Key is member and value is cost the member paid.
• event_log - Hash created from a method. Key is date, value is an array. Array contains location at index 0 and the attendees_hash at index 1.

ClubEvent Methods

The define_costs_for_event method creates a new CheckSplitter object and stores the split as the per_person instance variable. It also stores the total_cost_single_pay instance variable as the cost of the meal plus tip, to be used if one person treats the group.

The store_attendees_and_costs method creates and populates the attendees_hash.

def store_attendees_and_costs(who_paid, people, per_person)
  @attendees_hash = {}
  if who_paid.downcase == "everyone"
    populate_attendees_hash(people, per_person)
  else
    populate_attendees_hash(people, 0)
    attendees_hash[who_paid] = total_cost_single_pay
  end
end

It's uses another utility method, the populate_attendees_hash, which iterates over the people array and populates the attendees_hash with members and their costs. In the store_attendees_and_costs method, an if-else statement is added to determine if everyone paid, or a specific person treated the group. If everyone paid, the attendees_hash value is populated with the per_person costs. If one person paid, the attendees_hash is still populated with all attendees, but their value is set to 0. Then the value at the key of who_paid is modified to be the total_cost_single_pay.

Finally, ClubEvent has the event_history_update method, which is used to create the event_log hash.

def event_history_update(date, location, attendees_hash)
  @event_log = {date => [location, attendees_hash]}
end

All of these methods are called when a new ClubEvent object is created, so the information is automatically created and stored.

DinnerClub Class

The DinnerClub Class was created to track and display dinner club events. It displays the history of club, as well as members and the total costs they've paid.

DinnerClub Instance Variables:

• running_balance - Hash. Member name as the key and the total costs the member has paid as the value
• club_history - Hash. Key is the date of an event, value is an array. The array contains the location at index 0, and another hash at index 1. The hash at index 1 holds the attendees of a specific event and how much they paid.

DinnerClub Methods:

The new_event method is used every time the Dinner Club has a new event. It creates a new ClubEvent object and requires the same parameters that a ClubEvent object takes (total_cost, tip_percentage, people, date, location, who_paid). The new_event method then runs three other methods: the club_history_update method, the running_balance_update method, and the display_running_balance method.

The club_history_update method takes two parameters: club_history and event_log. club_history is the hash created when the DinnerClub object is created, and event_log comes from the new_event method, which calls the event_log instance variable from the ClubEvent class.

def club_history_update(club_history, event_log)
  club_history.merge!(event_log)
end

The club_history_update method destructively merges the club_history hash with the event_log hash.

The running_balance_update method takes two parameters: the running_balance hash and the club_history hash. It's used to update the member name and their total cost paid throughout the history of the club.

def running_balance_update(running_balance, club_history)
  club_history.each do |date, array|
    array[1].each do |name, amount|
      running_balance[name] += amount
    end
  end
end

The running_balance_update method works by iterating over the club_history hash, and then accessing the array stored as the value in the hash. It then takes that array and looks at index 1, where the attendees_hash was stored in the new_event method. From there, it iterates over the hash at index 1 and adds the name of each member as the key to running_balance and adds the cost each member paid to the current value of running_balance. The default value of running_balance is set to 0, so if there is a new member, it adds on to 0.

The display_running_balance method only takes the running_balance as a parameter and displays the member names and total costs paid.

def display_running_balance(running_balance)
  puts "\n"
  puts "Member Name".ljust(20) + "Member Balance".rjust(10)
  35.times {print "-"}
  puts "\n"
  running_balance.each do |name, balance|
    puts "#{name}".ljust(20) + "$#{sprintf("%0.2f", balance)}".rjust(10)
  end
  puts "\n"
end

The method puts a blank line, then puts the header information to display like a table. It left and right justifies the headers. The method then prints a dash 35 times to create the look of a dashed line. Then another line break is entered to follow the dashed line. Finally, the method iterates over running_balance to display member name left justified, then balance, formatted to display as currency, right justified.

The final method in DinnerClub is display_history, and uses the club_history as the parameter. It works exactly the same as display_running_balance, but instead iterates over the club_history hash.

club_history.each do |date, array|
  puts "#{date}\t#{array[0]}\t\t" + "#{array[1]}".rjust(25)
end

This displays three columns of information: date, location, and attendees_hash, which displays members and the costs they paid at the event. This method is only displayed if called, and is not automatically ran anywhere in the DinnerClub Class.