ema

Ema provides a simple and easy abstraction to build REST service.

Ema is a very little library built on top of Liberator.

The main idea is too provide a simple and yet powerful abstraction over Liberator itself.

Dependencies

Maturity

The project has just started thus it is not mature enough for any use.

Implemented

• MongoDB layer
• bidi (routing) layer

To Be Implemented

• Authentication
• Manage Middleware
• GET search
• SQL layer

Usage

The project is still unusable for any non-trivial project.

However you can already have an idea of the way to use Ema

Create a new clojure project

lein new awesome-name

Make the project.clj look like this.

(defproject awesome-name "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.6.0"]
                 [ema "0.0.3"]] ;; added
  :ring {:handler awesome-name.core/app}) ;;added

Note that I have added the dependecies and a ring handler.

At this point we need to generate our handler.

(ns awesome-name.core
  (:require [ema.core :refer [ema]]))

(def setting
  {:handler :bidi
   :uri "mongodb://localhost:27017"
   :database "ema"
   :resources [{:key :mongo
	            :name "user"
				:authentication :second
				:item-entries [:get :patch :delete] ;; miss put
                :collection-entries [:post :get]}
               {:key :mongo
			    :database "session" ;; attention here
				:name "session"
                :item-entries [:put] ;; miss get patch delete
                :collection-entries [:get :post]}]
   :authentication {:second {:key :basic
                             :uri "https://www.auth.com/awesome-app"
                             :collection "user"
                             :username "username"
                             :password "password"}}})

(def app
  (ema setting))

Now you need to run an instance of MongoDB in your machine, or just change the uri key in something more appropriate, like the url of a cloud instance of MongoDB.

Now, if everything went smootly you are serving two REST resource, user and session.

Please note the configuration: you won't be able to put on user nor you will be able to get, patch and delete a single session.

Of course you can change that.

Also, user and session are not in the same database (in the mongodb meaning).

user is in the "ema" database while session is in the "session" database.

If you add other collections, let say author and book

{
 :name "authors"
 :collection-entries [:post :get]
 :list-entries [:get :put :patch]
}
{
 :name "book"
 :database "another-database"
 :collection-entries [:post :get]
 :list-entries [:get :put :patch]
} 

author will be under the "ema" database while book will write in the "another-database".

simo@simo:~/ema$ curl -X POST -d "{\"siscia\" : \"pass\"}" http://localhost:3000/user
{"siscia":"pass","_id":"5423934fc8300b83ff02e5fe"}
simo@simo:~/ema$ curl  http://localhost:3000/user
{"data":[{"_id":"5423934fc8300b83ff02e5fe","siscia":"pass"}]}

Contributing

As always contributing is very much welcome. Just send a Pull Request or Open an Issue.

License

Copyright © 2014 Simone Mosciatti

Distributed under the Eclipse Public License either version 1.0

Thanks

Thanks to Emanuela Furfaro for being my muse.