The first step was to implement a dataengine, which would be used to make API calls to the build service API. For a long time, this remained the bottleneck for the project. The implementation was done with C++, and using the Qt Libraries. I used the Qt Network Libraries instead of the KDE Libraries, simply as I am more comfortable with them. Till very recently, I was not sure on how to pass parameters to the dataengine, but with help from #plasma, this is now resolved. The dataengine for displaying the build results of a package is complete, though I still cant test it, as it does not show up on the list of installed dataengines. I am yet to resolve this issue.
Link to Project:https://gitorious.org/build-service-plasma-widgets