This script creates a nice code editor thanks to the beautiful ace library for the groovy command in jenkins job configurations. The files mode-groovy.js theme-textmate.js should be in the directory jenkins/userContent The ace library itself can be set in the javascript console. This script is tested only with chrome.

jenkins-groovy-command-ace-support.js

ace.config.set("modePath", "/userContent");
ace.config.set("themePath", "/userContent");

var groovyCommand = document.getElementsByName("groovy.command")[0];
groovyCommand.setStyle('position:absolute;top:-10000px;left;-10000px;');

var editor = document.createElement('div');
editor.setAttribute('id','editor');
editor.setStyle('position:relative; width:100%; min-height:500px;');
editor.textContent = groovyCommand.textContent;


groovyCommand.parentElement.insertBefore(editor, groovyCommand);
var aceEditor = ace.edit("editor");
aceEditor.setTheme("ace/theme/textmate");
aceEditor.getSession().setMode("ace/mode/groovy");
aceEditor.getSession().on('change', function(){
  groovyCommand.textContent = aceEditor.getSession().getValue();
});