I did some investigation into building the RESTful API for the software licensing system using wicket. At first I was encouraged that URL management was so easy (nevermind that really old article I just linked to). Wicket Not Ideal for RESTful APIs In the end I decided that wicket was not a good choice for the RESTful API. The crux came in treating HTTP methods differently. In other words, for a given resource URI, I want to do something different for GET, POST, PUT and DELETE. That’s not one of wicket’s strengths, so......
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I’m starting to build out the RESTful API for the software licensing system. The first api call to implement is this http://mysite/api/sitelicenses/?apikey=KEYVAL That came from the initial design documents and implicitly suggests that there is a difference between the resource and parameters passed in when asking for the resource. This distinction is important and came up today when I was thinking about pagination. As the API is defined currently, the above URI would return all site licenses associated with an apikey. The first thought that came to mind was that the number of......
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In the current series of articles I’ve been talking about development of a system to enable premium wordpress plugins to be protected by licenses. While working on the design and going through a brain storming session yesterday with a colleague I had two small realizations. The first is that from the beginning I have planned to keep the WordPress coupling separate from the main licensing API. In fact, I haven’t planned to include any WordPress specific or shopcart type features in the API. This provides me with some benefits. One is that it......
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For the user interface layer of the licensing system I was interested in using a framework like Wicket. It was a lot of work to setup. The process was made somewhat frustrating by the fact that most of Google’s results are a few years old and deal with older versions. I did finally get it working and here’s the process. Other articles take the default Google App Engine project and modify it to accommodate wicket. I decided to go the other direction and start with the wicket quickstart. This is the process I......
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In the first article in this series, I sketched out some of the basic design ideas for the wordpress plugin licensing system. The next step is to come up with some more concrete details about how the application will work, what information it will manage and what the interfaces will look like when accessing it. I really like using the UML as I flesh out a design. In particular I find the class diagram and activity diagram useful. I frequently make use of stereotypes to extend the meaning of my classes. I’m not......
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How frameworks came to be Engineers have a few potentially conflicting tendencies that can become very pronounced in the software they write. One tendency is that we’re empire builders. In other words, we build, enhance, improve and in other ways expand the scope of our software solutions over time. Not to mention that we want our solution to be accepted, embraced and adored as the best possible solution for the problem we set out to solve. The result of this tendency can be seen in the ever growing, ever more complex frameworks available......
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Having chosen Google App Engine and Java as the target for initial development it’s time to setup a development environment. Google provides a plugin to Eclipse that makes this easy. They do a great job explaining how to setup the environment at this URL: http://code.google.com/appengine/docs/java/tools/eclipse.html Setup problems One hang up I had was an error when first trying to install the plugin in eclipse. It complained about “An error occurred while collecting items to be installed”. Several files came back saying “Unable to read repository” and “Read timed out”. It was possible to......
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In the introduction to this series, I outlined some of the requirements for the WordPress plugin licensing platform: Speed, reliability and scalability. These are critical. Just imagine what would happen if any of those were missing. Requirements Justification A slow platform might result in significantly fewer sales. One of our use cases is to provide a free, limited time trial, and poor performance when installing or using a plugin would almost certainly decrease sales conversions. Reliability issues would, at a minimum, reduce developer confidence when coupling a new plugin to the licensing platform.......
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The market for premium wordpress plugins is very active these days. Despite the disagreement over GPL specifics, there are an increasing number of extremely skilled software developers that create high quality plugins for WordPress. One problem that they all have is a licensing mechanism that will allow them to distribute their software plugin freely, but restrict its use to those who have paid. In some cases it is desirable to provide a free limited time trail. In this series of articles I’m going to show you how I develop a licensing system for......
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MongoDB implements a form of replication they call replica sets. Referring to a repica set instead of just calling it replication is a helpful distinction that becomes more obviously useful when you are introduced to sharding in MongoDB since each shard should be comprised of a set of replicas unique to that shard, but we’ll get to that later. For now, I want to show you how easy it is to setup and use replica sets. The setup and initial ‘recovery’ of data to all replicas in the set is quite simple. In......
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