Now, let's look at a few new aspects! An order is of two types; either a lease or a purchase. The Order model can be written as follows:
# app/models/order.rb class Order include Mongoid::Document field :created_at, type: DateTime field :type, type: String # Lease, Purchase belongs_to :book belongs_to :member embeds_one :lease embeds_one :purchase end
The Purchase model can be written as follows:
# app/models/purchase.rb class Purchase include Mongoid::Document field :quantity, type: Integer field :price, type: Float embedded_in :order end
The Lease model can be written as follows:
# app/models/lease.rb class Lease include Mongoid::Document field :from, type: DateTime field :till, type: DateTime embedded_in :order end
Here we are following the standard paradigm for a type field. If the type is :lease, we shall look up the Lease embedded object. If it's :purchase, we shall look up the Purchase embedded object. We could have made this polymorphic, but then how will we learn the different ways of coding?
What are routes, did you say? They are the URLs that we shall use to access the application from the web browser. Rails goes one step further and sets up RESTful routes by default.
RESTful interfaces are the definition of resources from which the URLs are generated. We can understand this better from the following table:
|
HTTP Verb |
Author Resource URL |
Controller Action |
Description |
|---|---|---|---|
|
|
|
|
List all Authors |
|
|
|
|
Show Author details |
|
|
|
|
Show the edit Author form |
|
|
|
|
Update Author |
|
|
|
|
Create Author |
|
|
|
|
Show the new author form |
|
|
|
|
Delete an Author |