Traim is a microframework for building a RESTful API service from your existing Active Record models.
gem install traimHere's a simple application:
# cat hello_traim.rb
Traim.config do |app|
app.logger = Logger.new(STDOUT)
end
class User < ActiveRecord::Base
end
Traim.application do
resource :users do
# Inject user model
model User
# Response json: {id: 1, name: “example"}
attribute :id
attribute :name
# POST /users
action :create
# GET /users/:id
action :show
# PUT /users/:id
action :update
# DELETE /users/:id
action :destroy
end
endPut your Active Record configuration in
config/database.yml
To run it, you can create a config.ru file
# cat config.ru
require 'hello_traim.rb'
run TraimThen run rackup.
Now, you already get a basic CRUD RESTful API from the User ActiveRecord model.
By default, action can be easily used to create an endpoint for CRUD operations. You can write your own endpoint as well.
Traim.application do
resources :users do
model User
attribute :id
action :show do
# attribute for single action
attribute :name
user = model.find_by_email params["email"]
user.name = "[admin] #{user.name}"
user
end
action :create
end
endResponse
{"id": 1, "name": "[admin] travis"}Create a nested JSON reponse with an Active Record association
class User < ActiveRecord::Base
has_many :books
end
class Book < ActiveRecord::Base
belongs_to :user
end
Traim.application do
resources :users do
model User
attribute :id
attribute :name
action :show
has_many: books
end
resources :books do
model Book
attribute :isbn
end
endResponse
{
"id": 1,
"name": "travis",
"books": [
{"isbn": "978-1-61-729109-8"},
{"isbn": "561-6-28-209847-7"},
{"isbn": "527-3-83-394862-5"}
]
}Member block can add actions to a specific record with id
Traim.application do
resources :users do
model User
attribute :id
attribute :name
member :blurred do
# GET /users/1/blurred
show do
record.name[1..2] = 'xx'
record
end
end
end
endCollection block can add actions to operate resources
Traim.application do
resources :users do
model User
attribute :id
attribute :name
collection :admin do
# GET /users/admin
show do
model.all
end
# POST /users/admin
create do
model.create(params)
end
end
end
endOrganize groups of resources under a namespace. Most commonly, you might arrange resources for versioning.
Traim.application do
namespace :api do
namespace :v1 do
resources :users do
model User
attribute :id
attribute :name
# endpoint: /api/v1/users
action :show
end
end
namespace :v2 do
resources :users do
model User
attribute :id
attribute :name
# endpoint: /api/v2/users
action :show
end
end
end
endYou can define helper methods that your endpoints can use with the helpers to deal with some common flow controls, like authentication or authorization.
Traim.application do
resources :users do
helpers do
def auth(user_id)
raise BadRequestError.new(message: "unauthenticated request") unless model.exists?(id: user_id)
# attribute can be added in helpers as well
attribute :name
end
end
model User
attribute :id
action :show do
auth(params["id"])
record
end
end
endBuilt-in attribute is generate response fields from model. Visual can help you present fields outside of model attributes.
Traim.application do
resources :users do
model User
attribute :id
attribute :name
attribute :vattr do |record|
"#{record.id} : #{record.email}"
end
action :show
end
endResponse
{"id": 1, "name": "travis", "vattr": "1 : travis"}Built-in model operations are using mass assignment. For security concern, Parameters can be whitelisted with permit option.
Traim.application do
resources :users do
model User
attribute :id
attribute :name
action :create, permit: ["name"]
end
end