shobhitratan / oo-relationships-astronaut-review

Review Lecture for OO Relationships [Mod 1 Review]

OO Relationships Review in Ruby

In this repo, we will be reviewing object relationships in Ruby, specifically the has_many through relationship (aka: many-to-many).

Introduction

You've just been hired by NASA to create an app that tracks all of their missions to Mars. The application needs to be aware of the astronauts, the shuttles, and each mission to the Red Planet.

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Setup (Code Overview)

Before you begin, first run the following command in your terminal to install the dependencies required for this lab:

bundle install

You can now add all of your Ruby files for your models in the app/models folder. You do not need to require them. They will be automagically required for you so long as you use the tools/console.rb file to run your code.

Through this file, we've provided to you a console that you can use to test your code. To enter a console session, run ruby tools/console.rb from the command line. You'll be able to test out the methods that you write here. Take a look at that file to see how you can pre-define variables and create object instances, rather than manually doing it in every single console session.

Your Job

Your goal is to build out all of the methods listed in the deliverables. Do your best to follow Ruby best practices. For example, use higher-level array methods such as map, select, and find when appropriate in place of each.

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Deliverables

Domain Modeling

First step is to model the domain you are building out. As a tracking application for all of NASA, Shuttles will have many Astronauts while Astronauts will be selected to ride on many Shuttles. How do they keep track of this? Individual Missions, of course! You cannot join a Shuttle without being selected for a Mission.

• What are your models?
• What does your schema look like?
• What are the relationships between your models?

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Basic Class Attributes and Methods

With your domain modeled, you now need to build out some basic functionality so that NASA HQ can create Missions for both Shuttles and Astronauts. So general searching type functionality.

Questions you should ask yourself:

• Do I need any other attributes?
• Should I write any other methods?
• Am I following Single Source of Truth?

SHUTTLE

• Shuttle#model
  • returns a String that is the model number of the shuttle
• Shuttle#capacity
  • returns a Fixnum that is the total number of astronauts that the shuttle can host
• Shuttle#add_astronaut
  • takes in an argument of an Astronaut instance and a launch date, and adds them to this shuttle's list of astronauts as long as it doesn't exceed the shuttle's capacity.
• Shuttle#current_astronauts
  • returns an Array of all the astronauts on this shuttle
• Shuttle.all
  • returns an Array of all of NASA's currently running shuttles
• Shuttle.find_by_model
  • takes a String argument of a model number and returns a Shuttle instance that matches that argument

ASTRONAUT

• Astronaut#name
  • returns a String that is the astronaut's name
• Astronaut#age
  • returns a Fixnum that is the age of the astronaut
• Astronaut#specialty
  • returns a String that is the astronaut's focus of study on Mars
• Astronaut#shuttles
  • returns an Array of this astronaut's shuttles
• Astronaut#join_shuttle
  • takes in an argument of a Shuttle instance and a launch date, and adds this astronaut to the shuttle's list of astronauts if it doesn't exceed that shuttle's capacity. If the shuttle is already full, print the following message: This shuttle is at capacity!.
• Astronaut.all
  • returns an Array of all the astronauts
• Astronaut.most_missions
  • returns an instance of an astronaut who has been to Mars the most times

MISSION

• Mission#launch_date
  • returns a Fixnum that is the launch year of this mission to Mars.
• Mission.all
  • returns an Array of all the missions

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Advanced Methods - Analytics!

Our tracking application has some basic functionality. Let's first make a commit!

git add .
git commit -m "can create shuttles astronauts and missions"
git push

Now we want to build out some useful features so Shuttles and Astronauts can get more value out of our app.

SHUTTLE

• Shuttle#average_age
  • returns a Float that is the average age of this shuttle's astronauts
• Shuttle#astronauts_specialties
  • prints out all of the specialties for this shuttle's astronauts
• Shuttle.smallest_mission
  • returns the Shuttle instance which has the least number of astronauts
• Shuttle.most_common_model
  • returns a String that is the most popular model number

ASTRONAUT

• Astronaut.top_three
  • returns an Array of astronauts; they are the three most active astronauts

MISSION

• Mission.first_launch
  • returns the Astronaut instances for the astronauts that were selected for the first mission to Mars

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BONUS!

Our platform is done! Let's commit our code again!

Now NASA wants to release this app so that their astronauts can use it to see their fellow shuttle members in advance of a mission. See if you can implement this method.

• Astronaut#fellow_mission_members
  • returns a unique Array of astronauts who have been on the same shuttle as you

A highly requested feature is to restrict ages for astronauts-- they need to be at least 25. See if you can implement this functionality.

• Shuttle#minimum_age
  • returns a Fixnum that is the minimum age required for astronauts
• Edit Shuttle#add_astronaut
  • takes in an argument of an Astronaut instance and adds them to this shuttle's list of astronauts
  • NOW this should function so that if the given Astronaut instance is not of age:
    • do not let them join the mission
    • print out a friendly message informing them that they are too young
    • don't forget that an astronaut cannot join a shuttle that is at capacity
• Edit Astronaut#join_shuttle
  • takes in an argument of a Shuttle instance and adds this astronaut to the shuttle's list of astronauts
  • NOW this should function so that if you don't meet the minimum age requirement of the given Shuttle instance:
    • do not let them join the mission
    • print out a friendly message informing them that they are too young
    • don't forget that an astronaut cannot join a shuttle that is at capacity

Congrats on finishing NASA's mission tracking app for Mars. Let's jump on a shuttle and make the first step towards exploring our solar system.