CHEM100 is a Clojure wrapper for the Apache Chemistry Client API. The name is a knock-off from Chemistry classes in college. The "100" refers to the 1.00 version of the CMIS Specification. Currently, there is CMIS for Java, Python, PHP, .Net and Objective-C. The marriage of a REPL (Read Evaluate Print Loop) and the CMIS API is a natural fit for live coding and interacting with a Content Management System (CMS).
Work in Progress
This API is very much a work in progress. I started working on this while working through the CMIS and Apache Chemistry in Action book. So, the amount of the wrapper that is completed varies based on the book and my own uses. However, it is possible to use the API with the current code. There are examples in Midje unit tests.
Why Clojure?
There are several advantages to using Clojure. First, it is a Lisp and of course it has a REPL. This gives us a shell out of the box. And while there are many Lisps available, Clojure interops with Java, which enables the devloper to rs-use all the existing Java Libraries. Some would say, "a better java than java". The other reason for Clojure is wrapping the CMIS API is almost trivial. There are a few "gotchas" when trying to create the parameters necessary to talk to the CMIS API, but nothing too difficult so far.
However, I admit, the most an important reason to use Clojure is that it is FUN. And it is amazing to execute code in the REPL and to see the effects inside of a CMS.
Clojure has a highly active group of supporters. Next Steps For the Developer, the next steps are dependent on how familiar you are with Clojure and Lisp's in general. There is good support for Clojure in Eclipse, IntelliJ, Vim and of course Emacs. Over time, I am adding Unit Tests using Midje. I am trying to include tests for each function.
For my testing, I have been using the "inmemory-cmis server", which is comes with the book "CMIS and Apache Chemistry in Action", which I recommend. And since I will be running my tests against the supplied Content Model/Content, it would make sense to have it handy. However, you don't have to have it available. In fact, all you need is CHEM100 and a Clojure REPL to get started.
Architecture A lot of the CMIS API functionality is in the Session Object. It is a very large object with a lot of methods. I have broken that up into individual Clojure Namespaces. And while this isn't absolutely necessary, it does present a more cohesive view of the API.
The other option was to create a single namespace with all the functions in it. So, most of the Namespaces correspond to logical groups of the Session Object methods. Some are artifacts of my development process. I started with running all my tests in core.clj, I am in the process of moving all of those to the Midje Unit Tests. So, eventually, core.clj will probably go away.
The "demo" namespace is the home of an interactive Demo I am creating, so it has a bunch of hard-coded values to speed up the demo process. And temp.clj is just a place to store code that I may or may not need in the future. I had to make a choice between having a single session and have all the functions use that one session or to pass the session into each function as a parameter. There are pros and cons to each method and I chose to pass the session in as a parameter.
Enterprise Content Management Systems I am currently working with the Inmemory CMIS Server for most of my testing. However, I will be actively testing with Alfresco in the near future. Content Management Interoperability Services (CMIS) Version 1.1 The 1.1 version of the specification was released on May 23, 2013. At this point in time, I don't think there is much support for it. However, at some point we will need a CHEM110.
