Class Set Up

3:37 with Jason Seifer

Now that we now how modules work, we’re going to write a simple program that simulates keeping inventory at a small retail store. The store sells shirts, pants, and accessories. We’re going to put everything together using modules, include, extend, and friends. Make sure to follow along using Workspaces.

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First, we'll create our module that will hold our inventory methods

module Inventoryable
end

class Shirt
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
  end
end

class Pant
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
  end
end

class Accessory
  attr_accessor :attributes

  def initialize(attributes)
    @attributes = attributes
  end
end

shirt1 = Shirt.new(name: "MTF", size: "L")
shirt2 = Shirt.new(name: "MTF", size: "M")

[MUSIC]. 0:00 Now that we know how modules work, we're going to write a simple program that 0:04 simulates keeping inventory at a small retail store. 0:08 The store sells shirts, pants and accessories. 0:13 We're going to put everything together using modules, include extend and 0:16 their friends. 0:21 Make sure to follow along now using Work Spaces. 0:23 Okay so let's go ahead and create our store. 0:27 So first what we're going to do is create a new file, and 0:31 we're just going to call this Store.rb. 0:35 Now our store is going to sell shirts, pants and accessories. 0:41 So let's go ahead and create a class for our shirts. 0:47 And the shirt is going to have an attribute accessor. 0:53 Called attributes. 0:59 And that's going to hold stuff like the name of the shirt, the size and 1:01 maybe whether or not it's in stock. 1:06 So when we instantiate an instance of the shirt class, 1:14 we're going to internally set the attributes, 1:20 [SOUND] to the attributes that are passed in. 1:25 So now let's go ahead and initialize a shirt, 1:30 we'll say shirt.new, name MTF for Mike the Frog. 1:35 And this comes in a size large. 1:41 And we can also say shirt 2, we'll change that to shirt 1, shirt.new name 1:47 Mike the Frog, and that comes in size medium. 1:53 Okay. 2:01 Well that looks fine. 2:02 I mean, this is something that we've already seen before. 2:03 Let's go ahead and make sure that we have pants too. 2:07 And actually, pants are going to do the same thing. 2:13 So we can copy that. 2:18 And paste it there. 2:22 So now what we want to do is create the pattern that we saw before 2:24 over in our tracking class here, where we had this tracking module, 2:29 we can create, access the instances, and find them as well. 2:35 So we want to do the same thing for our store. 2:42 Now we're gonna initialize pants and 2:45 also create the accessories class a little bit later. 2:47 Accessory we'll do now. 2:51 [SOUND] Okay, so 2:52 we have our three different classes, shirts, pants and accessories. 2:57 But what we wanna do is be able to track all these in inventory. 3:03 So, we're gonna make a module for that. 3:09 And the module is called Inventoryable. 3:12 Which just says that whatever class 3:17 this module is included in is going to be able to have something. 3:20 In inventory. 3:23 Now we'll get to that in just a moment. 3:26 In our next video we're going to start including different class methods and 3:28 writing those in our inventoryable module. 3:34

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Ruby Modules

Class Set Up

Code Samples