loopback-boot/docs/migrating-from-1x-to-2x.md

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);

App settings

The files with applications settings were renamed from app.* to config.*. Rename the following files to upgrade a 1.x project for loopback-boot 2.x:

• app.json to config.json
• app.local.json to config.local.json
• app.local.js to config.local.js
• etc.

Data sources

The configuration of data sources remains the same in both 1.x and 2.x versions.

Models

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();
    };
  };

3. If your model definitions are not in ./models, then add an entry to models.json to specify the paths where to look for model definitions.

models.json

{
    "_meta": {
      "sources": ["./custom/path/to/models"]
    },
    "Car": {
      "dataSource": "db"
    }
}

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" }
}