https://github.com/hackvan/objects-has-many-through

https://github.com/hackvan/objects-has-many-through

Last synced: 3 months ago
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• Host: GitHub
• URL: https://github.com/hackvan/objects-has-many-through
• Owner: hackvan
• License: other
• Created: 2018-07-07T01:56:32.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-07-07T02:34:35.000Z (almost 7 years ago)
• Last Synced: 2025-01-05T17:13:22.362Z (5 months ago)
• Language: Ruby
• Size: 7.81 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE.md

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README

        
# Ruby Object Relations: Has-Many-Through Lab

## Objectives

1. Write classes that are related to each other via the "has-many-through" relationship.

2. Write methods that use the "has-many-through" relationship to deliver information on related objects.

## Overview

In this lab, we'll be dealing with two sets of three classes.

We have a `Song`, `Artist` and `Genre` class. Songs belong to an artist and belong to a genre. A genre has many songs and an artist has many songs. An artist has many genres through its songs and a genre has many artists through its songs.

We also have an `Appointment`, `Doctor` and `Patient` class. Appointments belong to a patient and to a doctor. A doctor has many appointments and a patient has many appointments. A doctor has many patients through its appointments and a patient has many doctor's through its appointments.

## Instructions

Start with the `Artist`/`Song`/`Genre` domain.

**The `Artist` model:**

* The `Artist` class needs a class variable `@@all` that begins as an empty array

* The `Artist` class needs a class method `.all` that lists each artist in the class variable

* An artist is initialized with a name and is saved in the `@@all` array.

* The `Artist` class needs an instance method, `#new_song`, that takes in an argument of a name and genre creates a new song. That song should know that it belongs to the artist.

* The `Artist` class needs an instance method, `#songs`, that iterates through all songs and finds the songs that belong to that artist. Try using `select` to achieve this.

* The `Artist` class needs an instance method, `#genres` that iterates over that artist's songs and collects the genre of each song.

**The `Song` model:**

* The `Song` class needs a class variable `@@all` that begins as an empty array.

* The `Song` class needs a class method `.all` that lists each artist in the class variable.

* A song should be initialized with a name, an artist, and a genre, and be saved in the `@@all` array.

**The `Genre` model:**

* The `Genre` class needs a class variable `@@all` that begins as an empty array.

* The `Genre` class needs a class method `.all` that lists each artist in the class variable.

* A genre should be initialized with a name and be saved in the `@@all` array.

* The `Genre` class needs an instance method, `#new_song`, that takes in an argument of a name and an artist and creates a new song. That song should know that it belongs to the genre.

* The `Genre` class needs an instance method, `#songs`, that iterates through all songs and finds the songs that belong to that genre.

* The `Genre` class needs an instance method, `#artists`, that iterates over the genre's collection of songs and collects the artist that owns each song.

Now let's move on to our `Doctor`/`Appointment`/`Patient` domain model.

**The `Doctor` model:**

* The `Doctor` class needs a class variable `@@all` that begins as an empty array.

* The `Doctor` class needs a class method `.all` that lists each artist in the class variable.

* A doctor should be initialized with a name and be saved in the `@@all` array.

* The `Doctor` class needs an instance method, `#new_appointment`, that takes in a date and an instance of the `Patient` class and creates a new appointment. That appointment should know that it belongs to the doctor

* The `Doctor` class needs an instance method, `#appointments`, that iterates through all appointments and finds those belonging to this doctor.

* The `Doctor` class needs an instance method, `#patients`, that iterates over that doctor's appointments and collects the patient that belongs to each appointment.

**The `Appointment` model:**

* The `Appointment` class needs a class variable `@@all` that begins as an empty array.

* The `Appointment` class needs a class method `.all` that lists each artist in the class variable.

* An appointment should be initialized with a date (as a string, like `"Monday, August 1st"`), a patient, and a doctor. The appointment should be saved in the `@@all` array.

**The `Patient` model:**

* The `Patient` class needs a class variable `@@all` that begins as an empty array.

* The `Patient` class needs a class method `.all` that lists each artist in the class variable.

* A patient is instantiated with a name and be saved in the `@@all` array.

* The `Patient` class needs an instance method, `#new_appointment`, that takes in an argument of a doctor and a date and creates a new appointment. The appointment should know that it belongs to the patient.

* The `Patient` class needs an instance method, `#appointments`, that iterates through the appointments array and returns appointments that belong to the patient.

* The `Patient` class needs an instance method, `#doctors`, that iterates over that patient's appointments and collects the doctor that belongs to each appointment.

View Ruby Object Relations: Has-Many-Through Lab on Learn.co and start learning to code for free.


View Has Many Objects Through Lab on Learn.co and start learning to code for free.