# sails-util-micro-apps

[![NPM](https://nodei.co/npm/sails-util-micro-apps.png?downloads=true&downloadRank=true&stars=true)](https://nodei.co/npm/sails-util-micro-apps/)

Inject self-contained Micro-Apps into your Sails App using a hook. Each micro-app is a mini sails app that you can develop decoupled from your main apps, which you then inject using this util.

>You can use [Micro App Generator: sails-generator-micro-app](https://npmjs.com/package/sails-generator-micro-app) to quickly generate an installable Micro-App.

This approach allows you to make mini app's that you can reuse in larger apps, thereby adopting a micro-services architecture in Sails.

## Features & Recommendations
- Create micro-apps and use hooks to inject them into your main Sails app via this util
- Each micro-app can contain:
  - models
  - controllers (both traditional and standalone actions)
  - helpers
  - services
  - configs
  - policies
  - routes
  - hooks (yes you can inject hooks into hooks)
  - micro-apps that can contain all of the above
- You can even extend existing modules in your main Sails app with specific methods/properties from your micro-app *
- Reuse code with confidence as you can test it in a self-contained micro-app before integrating it into larger totally unrelated multiple apps
- Since a micro-app can be carried in an installable hook, it can have other hooks and micro-apps that it depends on and carries. When the micro-app is injected via the hook
  the whole shebang is injected into the main app and this means a micro-app can inject other micro-apps that can inject their own micro-apps and so on,
  building more like a dependency tree of micro-apps
- A single hook can inject multiple micro-apps
- Share micro-apps with other engineers
- Supports and written for Sails v1
- Simple intuitive injecter interface

NB: * take with a grain of salt

## Installation

You have to install it in the project you intend to inject the micro-apps.

Run this command to install and add the package as a dependency in your package.json :

```cli
npm install --save sails-util-micro-apps
```

## How to use it

You can find a complete hook example below or see tests [test folder](https://github.com/emahuni/sails-util-micro-apps/tree/master/test), [see below](#testing) for explanation.

Using this module is pretty easy.

In your hook's `index.js` file (`parentModule`), require this module and pass your Sails app as first argument. The second argument is the api dir, which is the micro-app's root directory (`microAppRootDir`), which defaults to: `parentModule.__dirname`:
```js
    module.exports = function(sails) {
        var loader = require('sails-util-micro-apps')(sails, 'path/to/micro-app/rootdir/');

        // or
        // var loader = require('sails-util-micro-apps')(sails); /* defaults to this __dirname */

        //... do other stuff

        return {
            initialize: function (next) {
                // ... do other stuff
            }
        };
    };
```

### Injecting hooks, config and policies

You can inject hooks, configs and policies with the `configure` method.
This method is synchronous and MUST be called before the hook initialisation, outside the initialize method.
If you don't want/need to inject hooks, configs or policies, you don't have to call this method.

Use it like this (complete hook example below):
```js
    // Automatically inject hooks, policies and configuration under microAppRootDir's ./config/ and hooks sources
    loader.configure();
```
Or like this if you want to inject from specific directories:
```js
    loader.configure({
        hooks:  '/absolute/path/to/hooks/',  // Path to the hooks to inject, it must be absolute
        policies:  '/absolute/path/to/policies/',  // Path to the policies to inject, it must be absolute
        config: '/absolute/path/to/config/' // Path to the config to inject, it must be absolute
    });
```

### Injecting models, controllers, helpers and services

To inject models, controllers, helpers and services, call the `inject` method also alised as adapt.
This method is asynchronous and must be called after the `configure` method.

Use it like this (complete example below):
```js
    /*
       Automatically inject:
        - models under microAppRootDir's ./api/models
        - controllers under microAppRootDir's ./api/controllers
        - helpers under microAppRootDir's ./api/helpers
        - services under microAppRootDir's ./api/services
    */
    loader.inject(function (err) {
        return next(err);
    });
```
Or like this if you want to inject from specific directories:
```js
    loader.inject({
        controllers: '/absolute/path/to/controllers', // Path to the controllers to inject, it must be absolute
        models: '/absolute/path/to/models', // Path to the models to inject, it must be absolute
        helpers: '/absolute/path/to/helpers' // Path to the helpers to inject, it must be absolute
        services: '/absolute/path/to/services' // Path to the services to inject, it must be absolute
    }, function (err) {
        return next(err);
    });
```

### Complete hook example

Here is a complete hook example. It's the `index.js` file of a Sails hook.
```js
    module.exports = function(sails) {
        var loader = require('sails-util-micro-apps')(sails); // infere the root micro-app dir automatically

        // Automatically inject hooks, policies and configs
        loader.configure();

        /*
            OR if you want to set a custom path :

            loader.configure({
                hooks: __dirname,// custom Path to hooks, usually the root of the micro-app
                policies: __dirname + '/api/policies',// custom Path to policies
                config: __dirname + '/config'// custom Path to config
            });
         */

         // ... do other stuff

        return {
            initialize: function (next) {
                /*
                    Automatically inject:
                     - models under hook's ./api/models
                     - controllers under hook's ./api/controllers
                     - helpers under hook's ./api/helpers
                     - services under hook's ./api/services
                */
                loader.inject(function (err) {
                    return next(err);
                });

                /*
                    OR if you want to set a custom path :

                    loader.inject({
                        controllers: __dirname + '/controllers', // custom path to controllers
                        models: __dirname + '/models', // custom path to models
                        helpers: __dirname + '/helpers' // custom path to helpers
                        services: __dirname + '/services' // custom path to services
                    }, function (err) {
                        return next(err);
                    });
                 */

                 // ... do other stuff
            }
        };
    }
```

#### Directory Structure

The micro-app hook should have a normal Sails app dir structure when used with the default path:
```
sails-hook-example-micro-app/
  |_index.js                                                <-- hook entry point (example file is above)
  |_package.json                                            <-- for installable hooks (other hooks or micro-apps
  | |_"sails-hook-example-inner-micro-app": "0.1.0"             installed as dependencies; sails convention)
  |_api/                                                    <-- api dir
  | |_hooks/
  | | |_...                                                 <-- this can be other micro-app hooks dependancies
  | |_controllers/
  | | |_...
  | |_models/
  | | |_...
  | |_helpers/
  | | |_...
  | |_services/
  | | |_...
  | |_policies/
  |   |_...
  |_config/
  | |_route.js
  | |_policies.js
  | |_...
  |_node_modules/
    |_sails-hook-example-inner-micro-app/                   <-- a dependency for the micro app being injected
    | |_...                                                 <-- all will be injected as above into main app
    |_...
```

## Development

Any suggestions, PRs, bug fixes, reports etc are welcome.

### Testing

Complete usage can be found in [`test` dir](https://github.com/emahuni/sails-util-micro-apps/tree/master/test). In a nutshell:
- Tests use mocha and chai, therefore run mocha (globally installed) from the project dir
- Tests Bootstrap (`test/helpers/bootstrap.js`) loads a normal sails app: `test/fixtures/app/` that loads a hook micro-app that loads a dependant micro-app
- Bootstrap loads 2 hooks around the ORM:
  - BeforeORM - `test/fixtures/sails-hook-before-orm/`
    - loads a dependant micro-app `BeforeHook`
  - AfterORM - `test/fixtures/sails-hook-after-orm/`
    - loads a dependant micro-app `AfterHook`
- Each of these hooks inject it's own micro-app using this module in its `index.js` file
- The tests assert the injected app as a tests control and micro-apps as the tests

You can learn usage example from there.

### Contributing

Please follow the [Felix's Node.js Style Guide](https://github.com/felixge/node-style-guide).

We use [semantic versioning](https://docs.npmjs.com/getting-started/semantic-versioning) for the NPM package.

### Author

- [Emmanuel Mahuni](https://github.com/emahuni)


### Attributions

Hard forked from [sails-util-mvcsloader](https://github.com/leeroybrun/sails-util-mvcsloader) by:

- [Leeroy Brun](https://github.com/leeroybrun)
- [Jimmy Aumard](https://github.com/jaumard)

no maintenance so had to redo it for sails 1 and a lot of new features and bug fixes

Sails internal hooks loading mechanisms, thanks Balderdashy

- [Sails](https://github.com/balderdashy/sails)


### TODO
- Add support for injecting :
    - Views
    - Assets
- Add Grunt for auto-JSHint & tests