application/collection+json

app.rb

require 'sinatra'
require 'rack/cache'
require 'sequel'
require 'sqlite3'
require 'yajl'

DB = Sequel.sqlite

DB.instance_eval do
  create_table :tasks do
    primary_key :id
    
    String      :description
    FalseClass  :completed, default: false
    
    DateTime    :created_at
    DateTime    :required_at
    
    Integer     :lock_version
  end
end

class Task < Sequel::Model
  plugin :optimistic_locking
  plugin :timestamps, update: nil
  plugin :boolean_readers
  
  alias :dateDue  :required_at
  alias :dateDue= :required_at=
  
  def_dataset_method(:date_range) do |start,stop|
    filter required_at: start..stop
  end
end

Task.create description: 'This is my first task', required_at: '2011-12-31'

Task.create description: 'This is my second task', required_at: '2011-12-29'

Task.create description: 'This is my third task', required_at: '2011-11-30'

use Rack::Cache

before do
  content_type 'application/collection+json'
end

get '/' do
  yajl :collection, locals: { items: Task.order(:required_at) }
end

post '/' do
  @task = Task.new.set_only Yajl::Parser.parse(request.body.read), [:description, :completed, :dateDue]
  @task.save
  
  redirect to '/'
end

get '/;queries' do
  yajl :queries
end

get '/;template' do
  yajl :template
end

get '/;all' do
  yajl :collection, locals: { items: Task }
end

get '/;open' do
  yajl :collection, locals: { items: Task.filter(completed: false) }
end

get '/;closed' do
  yajl :collection, locals: { items: Task.filter(completed: true) }
end

get '/;date-range' do
  yajl :collection, locals: { items: Task.date_range(params[:'date-start'], params[:'date-stop']) }
end

before %r{^/(?<id>\d+)} do
  @task = Task[params[:id]] || not_found
  
  etag @task.lock_version
end

get %r{^/\d+} do
  yajl :item, locals: { item: @task }
end

put %r{^/\d+} do
  @task.update_only Yajl::Parser.parse(request.body.read), [:description, :completed, :dateDue]
  
  redirect to '/'
end

delete %r{^/\d+} do
  @task.destroy
  204
end

error Sequel::ValidationFailed, Sequel::HookFailed do
  redirect back
end

__END__
@@item
json = {
  collection: {
    href: url('/'),
    version: '1.0',
    
    links: [
      { rel: 'author', href: 'mailto:mamund@yahoo.com', prompt: 'Author' },
      { rel: 'profile', href: 'http://amundsen.com/media-types/collection/profiles/tasks/', prompt: 'Profile' },
      { rel: 'queries', href: url('/;queries'), prompt: 'Queries' },
      { rel: 'template', href: url('/;template'), prompt: 'Template' }
    ],
    
    items:
      [
        {
          href: url("/#{item.id}"),
          data: [
            { name: 'description', value: item.description, prompt: 'Description' },
            { name: 'completed', value: item.completed?, prompt: 'Completed' },
            { name: 'dateDue', value: item.dateDue, prompt: 'Date Due' }
          ]
        }
        
      ]
  }
}
  
@@collection
json = {
  collection: {
    href: url('/'),
    version: '1.0',
    
    links: [
      { rel: 'author', href: 'mailto:mamund@yahoo.com', prompt: 'Author' },
      { rel: 'profile', href: 'http://amundsen.com/media-types/collection/profiles/tasks/', prompt: 'Profile' }
    ],
    
    queries: [
      { rel: 'all', href: url("/;all"), prompt: 'All tasks' },
      { rel: 'open', href: url("/;open"), prompt: 'Open tasks' },
      { rel: 'closed', href: url("/;closed"), prompt: 'Closed tasks' },
      { rel: 'data-range', href: url("/;date-range"), prompt: 'Date Range',
        data: [
          { name: 'date-start', value: '', prompt: 'Start Date' },
          { name: 'date-stop', value: '', prompt: 'Stop Date' }
        ]
      }
    ],
    
    template: {
      data: [
        { name: 'description', value: '', prompt: 'Description' },
        { name: 'dateDue', value: '', prompt: 'Date Due (yyyy-mm-dd)' },
        { name: 'completed', value: '', prompt: 'Completed (true/false)?' }
      ]
    },
    
    items:
      items.map do |item|
        {
          href: url("/#{item.id}"),
          data: [
            { name: 'description', value: item.description, prompt: 'Description' },
            { name: 'completed', value: item.completed?, prompt: 'Completed' },
            { name: 'dateDue', value: item.dateDue, prompt: 'Date Due' }
          ]
        }
      end
  }
}

@@queries
json = {
  collection: {
    href: url('/'),
    version: '1.0',
    
    links: [
      { rel: 'author', href: 'mailto:mamund@yahoo.com', prompt: 'Author' },
      { rel: 'profile', href: 'http://amundsen.com/media-types/collection/profiles/tasks/', prompt: 'Profile' }
    ],
    
    queries: [
      { rel: 'all', href: url("/;all"), prompt: 'All tasks' },
      { rel: 'open', href: url("/;open"), prompt: 'Open tasks' },
      { rel: 'closed', href: url("/;closed"), prompt: 'Closed tasks' },
      { rel: 'data-range', href: url("/;date-range"), prompt: 'Date Range',
        data: [
          { name: 'date-start', value: '', prompt: 'Start Date' },
          { name: 'date-stop', value: '', prompt: 'Stop Date' }
        ]
      }
    ]
  }
}

@@template
json = {
  collection: {
    href: url('/'),
    version: '1.0',
    
    links: [
      { rel: 'author', href: 'mailto:mamund@yahoo.com', prompt: 'Author' },
      { rel: 'profile', href: 'http://amundsen.com/media-types/collection/profiles/tasks/', prompt: 'Profile' }
    ],
    
    template: {
      data: [
        { name: 'description', value: '', prompt: 'Description' },
        { name: 'dateDue', value: '', prompt: 'Date Due (yyyy-mm-dd)' },
        { name: 'completed', value: '', prompt: 'Completed (true/false)?' }
      ]
    }
  }
}