Drag and Drop Visual Programming

2 main conclusions resulted from examining the history of end-user computing :-

• Research that created prototype systems for specialist users, school children, and other researchers and programmers, but failed to take make headway in the mass market can be reused with more up to date technology to assist development.

• More pragmatic research that involved creation of tools for the mass market, but which avoided more long term research issues can now be extended.

One mechanism for applying new technologies for use in end-user programming is drag and drop programming.

Repenning (2007) explains the need for enhancements to UML to aid end-user programming. Repenning also argues that "Visual programming languages using drag and drop mechanisms as the programming approach makes it virtually impossible to create syntactic errors." So "With the syntactic challenge being - more or less - out of the way we can focus on the semantic level of End-User Programming." This can make a high level model driven approach to production of better models possible. Rosson (2007) also explains about creation of a web-based drag and drop interface.

Ways that research is pursued in this thesis in order to make User Driven Programming possible are:-

1. Semantic Web and Web 2.0 approach to enabling User Generated Content.

2. User Centric Extensions to UML (Unified Modelling Language) e.g. (Vernazza, 2007) this approach also ventures into 1 and 3).

3. Visual Programming Extensions to spreadsheet type formulae based modelling enabled using approach 1.

Approach 1 is illustrated by Yahoo Pipes (2008) which provides for drag and drop editing of visual components that can combine, sort, and filter RSS data sources in order to automate web application development. This enables modelling of information, and using such diagrammatic programming combined with enabling of calculations would combine these three ways of producing applications. Yahoo Pipes enables creation of modelling applications with Semantic Web information, so this could assist in providing more incentive for provision of Semantic Web information and applications to use it.

So there is considerable overlap between these three approaches and they must be integrated within interdisciplinary research to enable user driven programming. One approach to this is a Semantic User Interface; this is explained in Vernazza (2007). This can enable Drag and Drop programming that combines the benefits of all three research approaches. The important factor is to connect the user interface with the underlying code, so the two share the same structure and users can properly see how their actions can change the actual code. This enables collaborative User-Driven programming.

References

Pipes and Filters for the Internet - http://radar.oreilly.com/archives/2007/02/pipes-and-filters-for-the-inte.html - O'Reilly - Feb 7 2007 - Yahoo!'s new Pipes service is a milestone in the history of the internet. It's a service that generalizes the idea of the mashup, providing a drag and drop editor that allows you to connect internet data sources, process them, and redirect the output.

Repenning, A., 2007. End-User Design. In: End-User Software Engineering Dagstuhl Seminar.

Rosson, M. B., 2007. Position paper for EUSE 2007 at Dagstuhl. In: End-User Software Engineering Dagstuhl Seminar.

Vernazza, L., 2007. Himalia: Model-Driven User Interfaces Using Hypermedia, Controls and Patterns In: IFAC/IFIP/IFORS IEA Symposium - Analysis, Design, and Evaluation of Human-Machine Systems Seoul, Korea - September 4-6th 2007 - International Federation of Automatic Control.

Yahoo Pipes [online]. Available from: http://pipes.yahoo.com/pipes/ [Accessed May 22nd 2008].

This is a Yahoo Pipes example created for the subject of Web 2.0/AJAX -

Yahoo Pipes RSS Feed for Web 2.0 - http://pipes.yahoo.com/pipes/pipe.info?_id=3e30625ebd44f24ff969ae5eef724425

An explanation of how to access and use the pipe created from a web page is at - Code Explanataion/Tutorial Freshblog - Blogger Hacks, Categories, Tips & Tricks - http://blogfresh.blogspot.com/2007/03/pipes-json-and-code-for-your-website.html.

Another article I wrote on Drag and Drop programming is at http://ezinearticles.com/?Drag-and-Drop-Programming&id=671578 and information and examples at http://www.cems.uwe.ac.uk/amrc/seeds/Ajax/ajax.htm#DragandDropProgramming