assignment.doc

CIS 282
Files Assignment

To turn in:
	Attach a file files_lastname.rb as an attachment to the assignment in Blackboard 
	Subject line: CIS 282, Name, Files

To do:
Take your program from the Hash Assignment and modify it to use files for storing the data instead of initializing the data at run-time.

Write a program that will read a datafile to initialize its Hash on startup.
When the user selects Exit, your program should then write the Hash into the same data file so that it can be read the next time it is run.  Any new items that are created by the user need to be written to the file at the same time.

The format of the file should be:
123,shirt,9.99
234,pants,19.50
456,socks,3.99

files_hartman.rb

# Now that the loop is gone, the program exits after each option. I choose an option, it exits. Not supposed to exit until I pick the Quit option! 
# Since I exit after each option, it doesn't save any new added items past the "Add" option exit. Writing new added items to the file -- as well as current products.txt items --  is one of the main points of the assignment. 
# The new item also has to be saved and included when I run option 5, lowest and highest-priced products, which is not possible when it isn't saved past the end of the Add block.
# Still need to figure out how to reconfigure my #5 to display in a user-friendly way. "472hat1597" is right, but not clear.

# Now that the loop is gone, the program exits after each option. I choose an option, it exits. Not supposed to exit until I pick the Quit option! 
# Since I exit after each option, it doesn't save any new added items past the "Add" option exit. Writing new added items to the file -- as well as current products.txt items --  is one of the main points of the assignment. 
# The new item also has to be saved and included when I run option 5, lowest and highest-priced products, which is not possible when it isn't saved past the end of the Add block.
# Still need to figure out how to reconfigure my #5 to display in a user-friendly way. "472hat1597" is right, but not clear.

hash_hartman_startover = {}
files_assignment = File.open( "products.txt", "r")
 
files_assignment.each_line do |line|
  id, name, price = line.chomp.split(',')
  # same as:
  # items = line.chomp.split(',')
  # id = items[0]
  # name = items[1]
  # price = items[2]
  hash_hartman_startover[id] = [name, price]
end
 
$stdout << hash_hartman_startover.inspect
 
 
 while true
	print "\n1. View all products
2. Add a new product
3. Delete a product
4. Update a product
5. View highest-priced product and lowest-priced product
6. View sum of all product prices
7. Quit \n
Choose an option: "
	$stdout.flush
	choice = gets.chomp.to_i


	if choice > 7
		print "That\'s not one of the choices. Try again: \n"
	end
 
	if choice == 1
		hash_hartman_startover.each{ |key, value|
		puts "#{key} - #{value[0]}, #{value[1]}"
		}
	end
 
	if choice == 2
		print "Enter the product name: "
		$stdout.flush
		name = gets.chomp.upcase
		print "Enter the product price using a decimal (as in 44.99), with no dollar sign: "
		$stdout.flush
		price = gets.chomp.to_f
 
		#generate random key, make sure it's unique
		key = rand(899) + 100
		while hash_hartman_startover.has_key?(key)
			key = rand(899) + 100
		end
 
		puts hash_hartman_startover[key] = [name, price]
		puts "You have entered a new product called #{name} with an assigned key of #{key}."
		puts hash_hartman_startover.inspect.upcase
	end
 
	if choice == 3
		hash_hartman_startover.each{ |key, value|
		puts "#{key} - #{value[0]}, #{value[1]}"
		}
		print "Enter the key number of the product you wish to delete: "
		$stdout.flush
		keynum = gets.chomp.to_i
 
		if hash_hartman_startover.has_key?(keynum)
			puts hash_hartman_startover[keynum]
			hash_hartman_startover.delete(keynum)
			hash_hartman_startover.each{ |key, value|
			puts "#{key} - #{value[0]}, #{value[1]}"
			}
 
 
		elsif ! hash_hartman_startover.has_key?(keynum)
			print "This product is not in the list.\n"
		end
	end
 
	if choice == 4
		hash_hartman_startover.each{ |key, value|
		puts "#{key} - #{value[0]}, #{value[1]}"
		}
		print "Enter the key number of the product you wish to update: "
		$stdout.flush
		keynumber = gets.chomp.to_i
	end
 
	if hash_hartman_startover.has_key?(keynumber)
		puts hash_hartman_startover[keynumber]
 
		print "Enter the name you want assigned to this product (it can be the same name as before): "
		$stdout.flush
		new_name = gets.chomp.upcase
		puts new_name.upcase
 
		print "Enter the price you want assigned to this product (it can be the same price as before): "
		$stdout.flush
		new_price = gets.chomp.upcase
 
		hash_hartman_startover.delete(keynumber)
		hash_hartman_startover[keynumber] = new_name, new_price
		hash_hartman_startover.each{ |key, value|
			puts "#{key} - #{value[0]} - #{value[1]}"
			}
 
	elsif ! hash_hartman_startover.has_key?(keynumber)
		print "This product is not in the list.\n"
	end
 
	if choice == 5
		hash_hartman_startover.each{ |key, value|
		puts "#{key} - #{value[0]}, #{value[1]}"
		}
		sorted = hash_hartman_startover.sort_by{|product| product[1] }
 
		puts "The cheapest product is #{sorted.last}"
		puts "The most expensive product is #{sorted.first}"
	end
 
	if choice == 6
		sum = 0
		hash_hartman_startover.each {|key, value|
		puts "#{value[1]}"
		sum += value[1]
		}
		puts sum
	end
 
	if choice == 7
		#~ files_assignment= File.open("products.txt", "w")
		#~ item_array = files_assignment.readlines
		#~ item_array.each{ |i| i.chomp!.upcase! }
		#~ files_assignment.puts item_array.join("\n")
		#~ files_assignment.close	
		#~ exit
  
		formatted_products = hash_hartman_startover.map do |key, value|
		"#{key},#{value.join(",")}"
		end
		formatted_products = formatted_products.join("\n")
		# $stdout << formatted_products
		
  
		files_assignment = File.open("products.txt", "w")
		files_assignment << formatted_products
		files_assignment.close
		exit
	end
 
	#This is a debugging exit, get rid of it when finished programming
	if choice == 8
		exit
	end
end

products.txt

243,tie,19.95
714,shoes,27.95
108,socks,99.99
472,hat,15.97