funzt.repl.system

[org.funzt/repl.system "0.1.0"]

Reloaded workflow development tool for systems built with component. Uses clojure.tools.namespace.repl for code reloading.

Usage

1. Invoke set-system-to-load! with a system map representing unloaded state.
2. Invoke (reset) whenever you want a full stop/code reload/start
3. Goto 1 when you need to spin up a different system

Accessing runtime instances

funzt.repl.system/system has a :system entry with a running or stopped system. This is where you access runtime instances of loaded components. Access runtime facilities for dev use via (get-in funzt.repl.system/system [:system <keyword-of-component-you-want>]). We recommend to set up little getter fn0s in your dev namespace for quicker access.

What if reset fails?

If reset fails due to bad code you should fix your code and hit reset again. If reset fails because a start method of a component has thrown, you likely have spawned headless IO facilities and should reboot the JVM.

clojure.tools.namespace.repl gotcha

Sometimes clojure.tools.namespace.repl finds too much code like generated ClojureScript source on the classpath. Use clojure.tools.namespace.repl/set-refresh-dirs to narrow down the source pathes you want reloaded.

Other features

• You may explicitly use start and stop instead of reset but usually won't have to.
• funzt.repl.system/system has a :status map with :started? and :stopped? keys. Usually you don't need it.

Similar tools

We use this tool at funzt.jetzt because it does as little as possible to provide a smooth reloaded workflow. At the time we wrote this there were no similar tools. Similar tools nowadays have features beyond our requirement and they require more work than just invoking (reset) from us.

License

Copyright © 2016 Leon Grapenthin & funzt.jetzt UG (haftungsbeschränkt)

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.