Recipes for LoopBack Models, part 4 of 5: Models by Instance Introspection

Last time, we looked at using LoopBack with relational databases, allowing you to consume existing data. This time around, we are looking at your options when the data does not have a schema.

I have JSON documents from REST services and NoSQL databases. Can LoopBack get my models from them?

Yes, certainly! Here is an example:


Now we understand that we can define the models from scratch, or discover them from relational databases or JSON documents. How can we make sure that the database models are in sync with LoopBack if some of the database models don’t exist or are different? LoopBack has APIs to facilitate the synchronization. We will demonstrate how next time, in the final part of this series.

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Recipes for LoopBack Models, part 3 of 5: Model Discovery with Relational Databases

In the prior part of this 5-part series, we looked at schema definitions and defined a model using an in-memory source to mock up the data access. This time around, we are looking at model discovery with existing  relational databases or JSON documents.

I have data in an Oracle database. Can LoopBack figure out the models and expose them as APIs to my mobile applications?

LoopBack makes it surprisingly simple to create models from existing data, as illustrated below for an Oracle database. First, the code sets up the Oracle data source. Then the call to discoverAndBuildModels() creates models from the database tables. Calling it with associations: true makes the discovery follow primary/foreign key relations.

For more information, please check out:

Discovery from relational databases is a quick way to consume existing data with well-defined schemas. However, some data stores don’t have schemas; for example, MongoDB or REST services. LoopBack has another option here. Find out more next time, when we will take a look at models by instance introspection in part 4 of this series.

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Recipes for LoopBack Models, part 2 of 5: Models with Schema Definitions

Last time, we looked at how you can mobilize data through LoopBack with open models, which works well for free-form style data.  This time around, we are looking at models with schema definitions.

I want to build a mobile application that will interact with some backend data. I would love to see a working REST API and mobile SDK before I implement the server side logic.

In this case, we’ll define a model first and use an in-memory data source to mock up the data access. You’ll get a fully-fledged REST API without writing a lot of server side code.

The snippet above creates a ‘Customer’ model with a numeric id, a string name, an array of string emails, and a numeric age. Please also note we set the ‘strict’ option to be true for the settings object so that LoopBack will enforce the schema and ignore unknown ones.

For more information about the syntax and apis to define a data model, check out:

You can now test the CRUD operations on the server side. The following code creates two customers, finds a customer by ID, and then finds customers by name to return up to three customer records.

To expose the model as a REST API, use the following:

Until now the data access has been backed by an in-memory store. To make your data persistent, simply replace it with a MongoDB database by changing the data source configuration:

For more information about data sources and connectors, please check out:

When defining a model, it may be troublesome to define all the properties from scratch. Fortunately, LoopBack can discover a model definition from existing systems such as relational databases or JSON documents, as we’ll show in part 3 next week.

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Recipes for LoopBack Models, Part 1 of 5: Open Models

Rich mobile applications are driven by data. Data can be produced and consumed by mobile devices, browsers, cloud services, legacy applications, databases, and other backend systems.

LoopBack mobilizes data through models that represent business data and behavior. LoopBack exposes models to mobile apps through REST APIs and client SDKs. You need to interact with the model differently, depending on the location and type of data. In this 5-part blog series, I’ll explain some of the most important recipes for working with LoopBack models:

  • Part 1: Open models – for free-form data.

  • Part 2: Models with schema definitions such as relational databases.

  • Part 3: Model discovery with relational databases – consuming existing data from a relational database.

  • Part 4: Models by instance introspection – Consuming JSON data from NoSQL databases or REST APIs.

  • Part 5: Model synchronization with relational databases – keeping your model synchronized with the database.

The source code is available at

Let’s start with the simplest one: open models.

I’m mobile developer. Can LoopBack help me save and load data transparently? I don’t need to worry about the backend or define the model up front, because my data are free-form.

For free-form data, use an open model that allows you to set any properties on model instances.

The following code creates an open model and exposes it as a REST API:

Notice the call to ds.createModel() with only a name to create an open model.

To try it out, enter the following command:

This command POSTs some simple JSON data to the LoopBack /forms URI.

The output that the app returns is a JSON object for the newly-created instance.

The id field is a unique identifier you can use to retrieve the instance:

Note: Your ID will be different as it is generated by the database. Please copy it from the POST response.

Try submitting a different form:

Now you see the newly created instance as follows:

For the complete list of REST APIs that LoopBack scaffolds for a model, please read:

If you have StrongLoop Suite (  installed, you can build and run this project from scratch in 5 commands:

Now open a browser and point it to http://localhost:3000/explorer.

You get an explorer to try the forms APIs right away. The UI is pretty straghtforward, feel free to play with it. For more information, check out:

The open model is simple and flexible. It works well for free-form style data because the model doesn’t constrain the properties and their types. But for other scenarios, a predefined model is preferred to validate the data and ensure it can be exchanged among multiple systems.

Next week, we’ll talk about models with schema definitions.

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Deploying LoopBack mBaaS on Rackspace

Fanatical Support Meets Strong Node

Fanatical Support has made Rackspace the leader in enterprise hosting. The Fanatical Support mantra, support for open source products, and strong SLA has made them the preferred vendor for IT ops in companies large and small. StrongLoop is excited to be one of the first available Node providers for their new Deployments service, which allows you to create and configure your multi machine Node topology in minutes.  StrongLoop Suite integration in the Control Panel means you’re 3 clicks from Strong Node, Strong-Ops, and LoopBack.

Push button, receive server

The easiest way for Rackspace customers to start using Node is via the Rackspace Control Panel. Log into your console at and select “Deployments” view on the right of the control panel.  The Rackspace Deployment Service is a new offering that makes it easy to automate the launching of your app in the Rackspace cloud. It works great with the StrongLoop Suite by automating an application and resource deployment in a best practice configuration.

To Startup a Rackspace hosted StrongLoop Application, login into your control panel and select  ‘Deployments’ on the right side of the Servers bar.


From the Rackspace “Create Deployment” panel insert your deployments name and select your region. Click the “StrongLoop LoopBack” Blueprint.


Then configure your StrongLoop server deployment options: Site Address, Admin settings and application name.ConfigurationOptions

Select your Deployment machine options.


Click the “Create Deployment” button to provision your server.

Fortunately the StrongLoop install pack is very lightweight so your newly configured StrongLoop Node server will be ready in a few minutes.  When you see the Server Status “go Green” you know your server is up and waiting for you.


Start Server, receive Open Node MBaaS

Now that you’re newly created StrongLoop server is up.  Lets take a look at what you get.

The StrongLoop Suite has three main components:  StrongNode, StrongOps and – most important for this posting – LoopBack.  LoopBack is an open source Mobile API tier.  The rest of this post will show you how to configure your loopback server and connect it to a Native iOS mobile application.

First take note of the public IP address that is presented to you once your server is activated.

We will use this IP address to configure the native mobile adapter allowing the iOS LoopBack SDK to connect to your mobile backend.  Let’s download the iOS example apps from the Github repo.  The LoopBack examples Repo has sample code to show you how to connect your mobile application to the LoopBack server using the native LoopBack SDK.  You can find additional documentation about LoopBack and the iOS SDK at the StrongLoop docs site .  This article will show you how to connect to the UITableView example, however configuring the MapView and custom remote method sample can easily be configured.


Once you have the repository cloned to your iOS development machine.

$git clone

Open the tableview-example.xcodeproj located at ‘loopback-examples-ios/ios-tableview-simple-example/tableview-example.xcodeproj’

The loopback-examples-ios applications has a LoopBack mobile server bundled with the repo ‘/loopback-examples-ios/loopback-nodejs-server’ that can be run on the developers host machine by calling ‘slc run app.js’ from within the server folder.  However, for this demo we will be leveraging our newly-provisioned LoopBack instance on the RackSpace cloud infrastructure.

Verify the Loopback server is running on the rackspace installation and the ‘products’ endpoint is available.  Open a web browser and point it to the LoopBack API explorer that come pre-configured with your LoopBack instance http://HOST-IP-ADDRESS:3000/explorer/.


Now that you have your StrongLoop Suite (Strong-Node, Strong-Ops and LoopBack) up and configured in your Rackspace environment, you can simply configure the native iOS application to point to the mobile API.

From within XCode project open the AppDelegate.m file and configure the adapter URL to “http://RACKSPACE_IP_ADDRESS”.


Run the Application in the XCode iOS simulator with by Pressing the Run button in the top left or using the hotkey combination (?+R) . From the simulator Click the ‘Inject Data’ button in the top left to insert 3 ‘product’ model instances into the LoopBack server.  Naturally you will see the Records appear on the mobile device, but you can also verify the server content by opening the API Explorer http://localhost:3000/explorer/#!/products/products_find_get_4  to the Get Request and pressing the ‘Try it out’ button.

Screen Shot 2013-09-17 at 7.51.47 AM

Additionally, you can add data to the backend from the API Explorer as well from the ‘POST’ button by inserting the model JSON data { “name”: “Matts Product”, “inventory” : 22 }  in the ‘Value’ field. Pressing Refresh on the mobile client will sync the tableView.

Notice the model definition is dynamic, allowing the mobile developer to dynamically add parameters to the ‘product’ mobile model type; allowing the mobile developer to quickly extend and configure the Mobile Object to fit the applications need.  LoopBack also supports static schema configuration for situations where the model data may be directly bound to a traditional static data stores such as Oracle or MySql.

Take some time and explore the mobile application as well as the LoopBack Node server. You can find more detailed information on how LoopBack handles both static and dynamic model types at ,and make and try give the integration a run on Rackspace


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