The easiest starting point is to get Clojure up and running with Leiningen. Leiningen is an essential Clojure tool that can create projects, resolve library dependencies, compile your code, run your tests, fire up a REPL and a whole lot more. You need Leiningen - and you can get away with just that and a text editor if your tooling needs are simple! Cake is another Clojure build tool, very similar to Leiningen, that uses the same project file format and offers a lot of the same functionality. Whilst Leinin[...]

Like many companies, we send HTML emails. This has always been extremely easy in CFML because it has a cfmail tag built-in which allows you to put HTML directly inline inside it - which in turn can include CFML code so the HTML can be dynamically generated on the fly. As we unravel parts of our application model and make them reusable from both CFML and Clojure code, we have to replace low-level CFML code with Clojure because, right now, CFML cannot be easily called from Java code, especially outside the S[...]

As mentioned earlier in this series, we have a process written in Clojure that reads updated member profiles from our MySQL database, converts them to XML and posts them to our search engine. XML generation in Clojure is made very easy by using a library called hiccup. For example, the following XML: <items> <item id="Clojure" type="language"> <emotion>Joyful!</emotion> </item> </items></pre> <p>is represented to hiccup as the following data structure:</p> <pre>[:items [:item {:id "Clojure" :type[...]

Our platform uses some minimal per-environment configuration to determine on which tier it is running: dev, CI, QA, production. We have a fairly large number of application settings which vary by tier, such as data sources, ports and hostnames for external services, email addresses to be used for error reporting and so on. We also toggle features on and off in different environments so we can always have working builds for deployment to production (feature toggles allow us to develop and test features as t[...]

I've touched on this in an earlier blog post about parsing PowerMTA accounting files but I wanted to cover it again as part of this blog series and go into a bit more depth. In that earlier post, I showed an outline for processing the large CSV files produced by PowerMTA but there are some interesting smaller pieces of the puzzle that warrant coverage too. The log files are sync'd from the PowerMTA Windows server to a directory on one of our Linux servers. The first part of the task is to get a list of jus[...]