Reloading Scripts in groovy, Erlang style

README.md

This script demonstrates reloading a script. So if you're running something in a loop, and want the ability to modify the code at runtime, this is your best bet.

I still have to figure out how to make it an annotation that you apply at the top of the script and have the whole script run in a loop.

<script src="https://gist.github.com/3145120.js?file=Foo.groovy"></script>

Foo.groovy

public class ReloadingScript {

  /**
   * The Class of the script
   */
  Class clazz

  /**
   * Runs the script in a Erlang-ish loop
   *
   * @param methodName The method in the script to run
   * @param loops The number of times to run it. -1 for infinite loop.
   * @param sleep The number of seconds to sleep between runs. >= 0.
   */
  public void runInLoop(String methodName, int loops, int sleep) {
    assert sleep >= 0
    String scriptFullName = clazz.protectionDomain.codeSource.location.path
    def scriptDir = new File(scriptFullName).parent
    def scriptName = new File(scriptFullName).name
    def engine = new GroovyScriptEngine(scriptDir)
    engine.config.minimumRecompilationInterval = 0

    if (loops >= 0) {
      loops.times {
        executeScript(engine, scriptName, methodName, sleep)
      }
    } else if (loops < 0) {
      while (true) {
        executeScript(engine, scriptName, methodName, sleep)
      }
    }
  }

  private void executeScript(engine, String scriptName, String methodName, int sleep) {
    clazz = engine.loadScriptByName(scriptName)
    def scriptInstance = (GroovyObject) clazz.newInstance()

    scriptInstance.invokeMethod(methodName, [] as Object[])
    Thread.sleep(sleep)
  }
}

void foo() {
  println "K"
}

new ReloadingScript(clazz: getClass()).runInLoop('foo', 20, 2000)