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JSON API full CRUD

If you want to configure a full crud JSON API, you will need to first generate a model with the following command (for this example we will use the model Post with title and body attributes):

amber generate model Post title body

This will generate a database migration and a Post model file in models/post.cr.

src/models/post.cr

class Post < Granite::Base
  connection pg
  table posts
column id : Int64, primary: true
column title : String?
column body : String?
end

Then in your controller:

src/controllers/post_controller.cr

class PostController < ApplicationController
  def index
    posts = Post.all
    respond_with 200 do
      json posts.to_json
    end
  end
def show
if post = Post.find params["id"]
respond_with 200 do
json post.to_json
end
else
results = {status: "not found"}
respond_with 404 do
json results.to_json
end
end
end
def create
post = Post.new(post_params.validate!)
if post.valid? &amp;&amp; post.save
  respond_with 201 do
    json post.to_json
  end
else
  results = {status: &quot;invalid&quot;}
  respond_with 422 do
    json results.to_json
  end
end


end
def update
if post = Post.find(params["id"])
post.set_attributes(post_params.validate!)
if post.valid? && post.save
respond_with 200 do
json post.to_json
end
else
results = {status: "invalid"}
respond_with 422 do
json results.to_json
end
end
else
results = {status: "not found"}
respond_with 404 do
json results.to_json
end
end
end
def destroy
if post = Post.find params["id"]
post.destroy
respond_with 204 do
json ""
end
else
results = {status: "not found"}
respond_with 404 do
json results.to_json
end
end
end

def post_params params.validation do required(:title, msg: nil, allow_blank: true) required(:body, msg: nil, allow_blank: true) end end end

And your routes file:

config/routes.cr

Amber::Server.configure do |app| pipeline :api do # pipelines... end

routes :api do # other routes,,, resources "/posts", PostController, except: [:edit, :new] end end