VTL Tools

Introduction and use case

Insee’s questionnaire factory overview

Specifying questions requires some script language (logic flow, variables)

Example of a question specification and rendering:

Example of complex questionnaire with controls.

Controls are currently specified in a custom XPath-like language that we want to replace by VTL. We need:

• JavaScript VTL editor to include in Pogues for the specification of controls
• A JavaScript VTL interpretor for the rendering next generation of CAPI questionnaires

For the transition:

• Eno needs to translate XPath controls into VTL for Lunatic
• We might need to translate from VTL to XPath for the current XFomrs platform

Nota bene: our needs are limited to simple validation expressions on scalars.

VTL Tools in JavaScript

• Leverage on components generated from the formal grammar by Antlr
• Open source on Insee’s GitHub repository
• Integration pipeline with Travis-CI and Coveralls

The editor

Inclusion of VTL in the Lunatic editor.

The interpretor

• Functional coverage