Creating interactive web data applications with spreadsheets

While more and more data are available through web services, it remains difficult for end-users to create web applications that make use of these data without having to write complex code. We present Gneiss, a live programming environment that extends the spreadsheet metaphor to support creating interactive web applications that dynamically use local or web data from multiple sources. Gneiss closely integrates a spreadsheet editor with a web interface builder to let users demonstrate bindings between properties of web GUI elements and cells in the spreadsheet while working with real web service data. The spreadsheet editor provides two-way connections to web services, to both visualize and retrieve different data based on the user input in the web interface. Gneiss achieves rich interactivity without the need for event-based programming by extending the 'pull model' of formulas that is familiar to the spreadsheet users. We use a series of examples to demonstrate Gneiss's ability to create a variety of interactive web data applications.