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Ruby Modules

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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.

Code Samples

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")

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    [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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