When I was learning to play the piano, I remember wanting to jump right into Billy Joel. “Hot Cross Buns” and “Mary Had a Little Lamb” were boring and very uncool for an eight year old boy to be learning.
I have had the same feeling while learning to code. I spent a lot of time doing methods, objects and classes never really getting to use them as I would in the real world.
There is one question I wanted to be able answer since the day I started programming: “How the hell do I interact with a program?”
Today, I figured that out. The code below is from the main program file for the game I created in the Pragmatic Studios course. In it, there are two examples of some of ruby’s basic input functions.
knuckleheads = StudioGame::Game.new("Knuckleheads") default_player_file = File.join(File.dirname(__FILE__), 'players.csv') knuckleheads.load_players(ARGV.shift || default_player_file) loop do puts "\nHow many game rounds do you want to play?" answer = gets.downcase.chomp case answer when /^\d+$/ knuckleheads.play(answer.to_i) when 'quit','exit' knuckleheads.print_stats break else puts "Please enter a number or 'quit'" end end knuckleheads.save_high_scores
The first input I learned was the “gets” method. Here, the program prompts the user to provide a number, the code checks that it is in fact a number (or a quit command) and then uses the number as an argument for the method.
loop do puts "\nHow many game rounds do you want to play?" answer = gets.downcase.chomp case answer when /^\d+$/ knuckleheads.play(answer.to_i) when 'quit','exit' knuckleheads.print_stats break else puts "Please enter a number or 'quit'" end
The next one is a little more complicated so I will try to break it up into pieces.
What I am trying to accomplish is to allow non-programmers to add players to my game using a csv file and no code. They should be able to simply input the name of a player and the program automatically adds a Player object to the game.
To do this I created a player.csv file (in the above code a person could theoretically create their own file and load it in) with a series of players each on their own line. Then I included the following code in my Game class:
def load_players (filename="players.csv") CSV.foreach(filename) do |line| player = Player.new(line, line.to_i) add_player(player) end end
This takes a file (defaulted with my players.csv) and goes through each line of the file, creating a Player object for each one.
Then, I included this in the main program file:
default_player_file = File.join(File.dirname(__FILE__), 'players.csv') knuckleheads.load_players(ARGV.shift || default_player_file)
This loaded the players from the file given by the user or my default file if none is give and then runs the program as normal.
So, after two months of hard work and a steep learning curve I have completed my first gem! w00t! You can download it if you want:
$gem install blam_and_woot
If you want to peek at the source code you can find ithere
I will be writing about packaging the gem and some issues I ran into with that later. For now, I am celebrating!