A 
Data Connector provides a reusable API that can be used by server-side events to interact with an external web service.
They can be created by right-clicking in the Entites tree and selecting New > Data Connector. In the resulting Create New Data Connector dialog you can create a new Data Connector or download one from the Resource Hub.
Newly created Data Connectors contain an initial code template that can be used as a starting point to interact with a RESTful web service. Downloaded Data Connectors are fully-functional Data Connectors that connect to a specific web service and instructions for how to use them can be found on the Resource Hub.
Data Connectors can be added to a 
Form by dragging it from the Entites Tree into the Form's Data Connectors View. Once added, any server-side event in the Form, its 
Pages and their 
Controls, can call any function in the Data Connector via the Verj.io JavaScript API's connectors interface. For example, to call myFunction() in a Data Connector called myDataConnector the following code could be used:
// call myFunction() in myDataConnector
connectors.dataconnectors.myDataConnector.myFunction();