loopback-example-app
v3.1.0
Published
LoopBack Example Application
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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, usememory
,mongodb
ororacle
IP
: The http server listener ip address or hostname, default to0.0.0.0
(any address)PORT
: The http server listener port number, default to3000
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.