Creating Your Own Data Connector

New Data Connectors are created with an initial code template to connect to a REST web service.

The template:

Adds the Data Connector to the connectors.dataconnectors JavaScript API, using its name.
Loads the Data Connector's Data Connector Configuration from the Verj.io Runtime Environment, using its name.
Initialises a Verj.io REST Data Connector object, passing in the base URI for the web service from the loaded Configuration.
Provides an example function that performs a GET on the web service.

The Verj.io REST Data Connector, restDataConnector, is the core component of a Data Connector and performs the communication with the web service by providing get(), put(), post(), delete(), patch() and head() functions.

Extending the Data Connector

A Data Connector is extended by adding functions to it that use restDataConnector to interact with one or more endpoints on the web service.

Any number of functions can be created in a Data Connector. It is useful to consider the actions your application may want to perform against the web service and combine several calls to the web service in one function.

Request headers, including authentication headers, can be configured in the restDataConnector, as can error handling functions.

Once a Data Connector is added to a Form (see Using a Data Connector), any server event from that Form, its Pages and their Controls can use your functions.

Steps

Step number

We are going to create a Data Connector that connects to a REST web service that simulates a coin toss.

The REST Service has an endpoint called flip that returns 'Heads' or 'Tails' depending on the result of the simulated coin toss.

If you haven't already, complete the Steps in the Workspace Basics Tutorial before starting these Steps.

Switch to your verjioTutorials Workspace if you haven’t already:

Click File > Switch Workspace.
Select verjioTutorials
Click OK.

Create a new Project called dataConnectorBasics, if it doesn't already exist:

Click New .
Select Project.
Name your project dataConnectorBasics
Click Finish.

Create a new Data Connector in a creatingDataConnectors Folder in this Project:

Right-click on the dataConnectorBasics Project and select New > Folder.
Name the Folder creatingDataConnectors.
Right click on the the creatingDataConnectors Folder and select New > Data Connector.
Name the Data Connector coinToss.
Click OK.

Add a flip() function to make a coin toss:

Double-click on coinToss to open the Data Connector.

Replace the example function with the following code:

	/**
	 * Performs a GET on an endpoint of the coin Web Service to perform a flip.
	 * 
	 * Example use:
	 * 	var result = connectors.dataconnectors.coinToss.flip();
	 * 
	 * @return 'Heads' or 'Tails' depending on the web service. 
	*/
	this.flip = function() {
		
		// Construct a URL to the endpoint to call. 
		const uri = restDataConnector.getUri('flip');

		// Perform a GET request on that endpoint.
		return restDataConnector.get(uri).flip;
	}

Save the Data Connector.

To see how to configure this Data Connector follow the steps in the Configuring a Data Connector Tutorial.

More samples, tutorials and demos