more_advanced_crud_rails.md

Background & Objectives

Now it's time to make a 3-model app! And you guessed it, we'll be introducing a many to many relationship (n:n). So what's the deal? Well, it's time to build a cocktail manager. We want to store our favourite cocktails, and their recipes.

Specs

Attributes

• A cocktail has a name (e.g. "Mint Julep", "Whiskey Sour", "Mojito")
• An ingredient has a name (e.g. "lemon", "ice", "mint leaves")
• A dose is the amount needed for each ingredient in a cocktail (e.g. the Mojito cocktail needs 6cl of lemon). So each dose references a cocktail, an ingredient and has a description.

Validation

• A cocktail must have a unique name.
• An ingredient must have a unique name.
• A dose must have a description, a cocktail and an ingredient, and [cocktail, ingredient] pairings should be unique.

Associations

• A cocktail has many doses
• A cocktail has many ingredients through doses
• An ingredient has many doses
• A dose belongs to an ingredient
• A dose belongs to a cocktail
• You can't delete an ingredient if it used by at least one cocktail.
• When you delete a cocktail, you should delete associated doses (but not the ingredients as they can be linked to other cocktails).

1 - Seed the ingredients

Our app will not allow users to create ingredients. Instead, we will generate a static seed of ingredients to choose from. Write this seed, for example

# db/seeds.rb
Ingredient.create(name: "lemon")
Ingredient.create(name: "ice")
Ingredient.create(name: "mint leaves")

2 - Routing, Controller, Views for Cocktails

Once again, you must have a precise idea of the features of your app in order to build your routes. Here is the list of features:

• A user can see the list of cocktails

GET "cocktails"

• A user can see the details of a given cocktail, with the dose needed for each ingredient

GET "cocktails/42"

• A user can create a new cocktail

GET "cocktails/new"
POST "cocktails"

3 - Routing, Controller, Views for Doses

• A user can add a new dose (ingredient/description pair) to an existing cocktail

GET "cocktails/42/doses/new"
POST "cocktails/42/doses"

• A user can delete a dose that belongs to an existing cocktail. How can we make a delete link again?

DELETE "doses/25"

Do we need an IngredientsController?

4 - Design as we go

Here are some great examples.

5 - New dose form on the cocktail show page (Optional)

Try to put the "New dose form" on the cocktail page, not on a separate page. What changes in the routes? And in the controllers?

6 - Let's add reviews for these awesome cocktails! (Optional)