loopback-example-app

Prerequisites

You must have already installed Node.js.

Install StrongLoop:

$ npm install -g strongloop

If you run into any issues, see Installing StrongLoop for more information.

i-Car Rentals Corp

i-Car is an (imaginary) car rental dealer with locations in major cities around the world. They need to replace their existing desktop reservation system with a new mobile app.

This application was created using LoopBack tools. See Building from scratch below for more details.

Run the application

Start the application back-end by running the following command:

$ node . 

Now open your browser and point it to http://127.0.0.1:3000 to access the application UI.

End user experience

The app enables customers to find the closest available cars using the i-Car app on a smartphone. The app shows a map of nearby rental locations and lists available cars in the area shown on the map. In addition, the customer can filter the list of cars by make, model, class, year and color. The customer can then select the desired car and reserve it via the app. If not logged in the app prompts the customer to login or register. The app indicates if the desired car is available and if so, confirms the reservation.

Features

• Authenticates and verifies customers' identities.
• Securely exposes inventory data to mobile applications.
• Allow customers to find cars available within a specific area.
• Allow customers to reserve cars for rental.

REST APIs

• /cars exposes a queryable (filter, sort) collection of available cars over HTTP / JSON
• /cars/nearby?&lat=...&long=... or ?zip=... returns a filtered set of available cars nearby the requesting user
• /cars/nearby?id=24&zip=94555 returns nearby cars of id 24.
• /cars/:id returns a specific car from the inventory, with specific pricing and images
• /users/login allows a customer to login
• /users/logout allows a customer to logout

Configuring the data source

By default, the sample application uses the memory connector and listens on the port 3000 on all network interfaces.

You can configure other data sources by adding a new key to DATASTORES object in rest/datasources.local.js:

var DATASTORES = {
  custom: {
    connector: 'my-custom-connector',
    // configuration for the custom connector
  },
  memory: {
  },
  // etc.
};

The sample can be configured using the following environment variables:

• DB: The db type, use memory, mongodb or oracle
• IP: The http server listener ip address or hostname, default to 0.0.0.0 (any address)
• PORT: The http server listener port number, default to 3000

For example,

• To run the application at port 3001 with MongoDB:

  $ DB=mongodb PORT=3001 node .
  

• To run the application at port 3002 with Oracle:

 $ DB=oracle PORT=3002 node .

Schema and specifications

Customer Database

The app will get all customer information from the SalesForce API.

Inventory Database

All car inventory is already available in an existing Oracle X3-8 Exadata database.

The Inventory DB schema looks like this:

Customers

• id string
• name string
• username string
• email string
• password string
• realm string
• emailverified boolean
• verificationtoken string
• credentials string[]
• challenges string[]
• status string
• created date
• lastupdated date

Reservations

• id string
• product_id string
• location_id string
• customer_id string
• qty number
• status string
• reserve_date date
• pickup_date date
• return_date date

Inventory_Levels

• id string
• product_id string
• location_id string
• available number
• total number

Car

• id string
• vin string
• year number
• make string
• model string
• image string
• carClass string
• color string

Location

• id string
• street string
• city string
• zipcode string
• name string
• geo GeoPoint

Inventory_View

View to return qty of available products for the given city.

• product (product name)
• location (location name)
• available (qty available)

Geo Lookup

Google's location API is used to return the users city from a given zip or lat/long.

Project files

The project is composed from multiple components.

• models/ contains definition of models and implementation of custom model methods.

• rest/ contains the REST API server, it exposes the shared models via REST API.

• website/ contains a simple single-page-application that is served when users open the project in the browser.

• server/ is the main HTTP server that brings together all other components.

• sample-data/ contains a set of sample models that are used to initialize the database with some data.

• test/ provides few basic unit-tests to verify that the server provides the expected API.

Refer to Creating an application for more information.

Building from scratch

You can create most of the sample application using LoopBack's Yeoman generators. See the slc loopback command-line reference for more information.

Install StrongLoop with npm install -g strongloop to install the LoopBack generators.

Once you have the generators installed, run the following command to recreate the sample app from scratch:

$ slc loopback:example example-app -l

This will call other generators like slc loopback and slc loopback:model to scaffold the application. You can learn more about these generators in the slc command-line reference.

When run with the -l option, the example generator prints a detailed list of steps that are executed to walk you trough the scaffolding process. You can re-run the steps manually yourself to get a better understanding of how the loopback generators work.

This is how the output looks like:

Create initial project scaffolding
  $ slc loopback:app loopback-example
    [?] Enter a directory name where to create the project: .
    [?] What's the name of your application? loopback-example


I'm all done. Just run npm install to install the required dependencies.


Add datasource geo
  $ slc loopback:datasource geo
    [?] Select the connector for geo: rest
  Set datasource options: operations
Add model Car
  $ slc loopback:model Car
    [?] Select the data-source to attach Car to: db
    [?] Expose Car via the REST API?
    [?] Property name:
  $ slc loopback:property
    [?] Select the model: Car
    [?] Enter the property name: id
    [?] Property type: string
    [?] Required? false
  Set property options: id
  (more properties follow in the output)
  Add relation Car hasMany Reservation
  Set model options: mysql mongodb oracle
Add model Customer
(and so on)

The first step is to prepare the project infrastructure by running slc loopback:app, which is an alias for slc loopback.

Then there is a geo datasource added by running slc loopback:datasource geo. When prompted for the connector to use, the rest is selected. After the datasource was created, the REST operations are added to the generated file datasources.json manually.

The next step is to create all application models. The generator slc loopback:model is called to define a new model, slc loopback:property to add a property definition to the new model. Some property options like "id": true are not supported by the generator, they are added manually.

Also model relations and per-datasource model configurations are not supported by the generator yet, as can be seen from these two lines:

  Add relation Car hasMany Reservation
  Set model options: mysql mongodb oracle

Open the file models/car.json too see what has been added by the generator.

When all models are defined, the example generator performs steps that you would do manually when working on a new application: add more dependencies to package.json, extend the models with custom behaviour, implement unit-tests, etc.