loopback-boot/docs/configuration.md

Configuration and conventions

Model Definitions

The following two examples demonstrate how to define models.

models/dealership.json

{
  "name": "dealership",
  "relations": {
    "cars": {
      "type": "hasMany",
      "model": "Car",
      "foreignKey": "dealerId"
    }
  },
  "properties": {
    "id": {"id": true},
    "name": "String",
    "zip": "Number",
    "address": "String"
  }
}

models/car.json

{
  "name": "car",
  "properties": {
    "id": {
      "type": "String",
      "required": true,
      "id": true
    },
    "make": {
      "type": "String",
      "required": true
    },
    "model": {
      "type": "String",
      "required": true
    }
  }
}

To add custom methods to your models, create a .js file with the same name as the .json file:

models/car.js

module.exports = function(Car, Base) {
  // Car is the model constructor
  // Base is the parent model (e.g. loopback.PersistedModel)

  // Define a static method
  Car.customMethod = function(cb) {
    // do some work
    cb();
  };

  Car.prototype.honk = function(duration, cb) {
    // make some noise for `duration` seconds
    cb();
  };

  Car.setup = function() {
    Base.setup.call(this);

    // configure validations,
    // configure remoting for methods, etc.
  };
}

Model Configuration

The following is an example JSON configuring the models defined above for use in an loopback application.

dataSource options is a reference, by name, to a data-source defined in datasources.json.

models.json

{
  "dealership": {
    "dataSource": "my-db",
  },
  "car": {
    "dataSource": "my-db"
  }
}

Migrating from 1.x to 2.x

Starting point: a sample 1.x project

models.json

{
  "car": {
    "properties": {
      "color": "string",
    },
    "dataSource": "db"
  }
}

models/car.js

var app = require('../app');
var Car = app.models.Car;

Car.prototype.honk = function(duration, cb) {
  // make some noise for `duration` seconds
  cb();
};

app.js

var loopback = require('loopback');
var boot = require('loopback-boot');
var app = loopback();
boot(app, __dirname);

Model definitions & configurations

The 2.x version of loopback-boot no longer creates Models, it's up to the developer to create them before booting the app.

The folder models/ has a different semantincs in 2.x than in 1.x. Instead of extending Models already defined by app.boot and models.json, it provides a set of Model definitions that do not depend on any application that may use them.

Perform the following steps to update a 1.x project for loopback-boot 2.x. All code samples are referring to the sample project described above.

1. Move all Model-definition metadata from models.json to new per-model json files in models/ directory.

models/car.json

  {
    "name": "car",
    "properties": {
      "color": "string",
    }
  }

models.json

  {
    "car": {
      "dataSource": "db"
    }
  }

2. Change per-model javascript files to export a function that adds custom methods to the model class.

models/car.js

  module.exports = function(Car, Base) {
    Car.prototype.honk = function(duration, cb) {
      // make some noise for `duration` seconds
      cb();
    };
  };

4. Modify the boot configuration to list the directory containing model definitions.

   var loopback = require('loopback');
   var boot = require('loopback-boot');

   var app = loopback();
   boot(app, {
    appRootDir: __dirname,
    modelSources: ['./models']
  });

Attaching built-in models

Models provided by LoopBack, such as User or Role, are no longer automatically attached to default data-sources. The data-source configuration entry defaultForType is silently ignored.

You have to explicitly configure all built-in models used by your application in the models.json file.

{
  "Role": { "dataSource": "db" }
}