Repository

A base class to structure the service layer in a resource-based app architecture

A what?

The Repository class is just an "interface" with common methods that allow actions to be taken on a resource:

find()
save()
remove()

Calling those methods won't do anything. You need to implement an adapter, which actually performs these actions. Each repository instance must have an adapter attached to it.

Usage

To create a new repository, you must give it a configuration.

Use Repository.new(config) to extend the default interface.

For example, let's create a resource that handles User entities.

const config = {
    name: 'User',
    adapter: restAdapter,   // any adapter that implements the interface
    options: {
        endpoint: '/users'
    }
};

class UserRepository extends Repository.new(config) {}

export { UserRepository };

Now you can create a new User in your app:

const user = {
    name: 'John Doe',
    email: '[email protected]'
};

const repository = new UserRepository();
repository.save(user);

Adapter

Since our config determined that a RestAdapter will be used in the user repository, the save method will send the user object to the adapter.

The repository name is passed as an argument to the adapter to make it easier to write a single adapter to handle all the requests.

An adapter method would look like this:

// any hypotetical service that handles HTTP requests
import { http } from 'http-service';

class RestAdapter {
    // ...

    /**
     * @param {String} repositoryName       Here called "User"
     * @param {*} data                      The object to save, i.e., user object
     * @param {Object} options              Repository configuration
     */
    save(repositoryName, data, options) {
        const endpoint = options.endpoint;

        if (data.id) {
            return http.patch(endpoint, data);
        }

        return http.post(endpoint, data);
    }
}

Extending the repository methods

You can add new methods on a repository if you need. They are just a regular JS class.

const config = {
    name: 'User',
    adapter: restAdapter
};

class UserRepository extends Repository.new(config) {

    blockUser: function(id) {
        // the repository instance and its methods are available here
        return this.save({
            id: id,
            active: false
        });
    }

    customAdapterMethod(entity, options) {
        return this.__call__('customMethod', entity, options);
    }
}