Simple grails controller action to evaluate groovy script for debugging

XyzController.groovy

    def eval = {
        def binding = new Binding(app:grailsApplication,request:request,session:session,controller:this)
        def result
        try { result = params.script ? new GroovyShell(binding).evaluate(params.script) : '(no script)' }
        catch (e) { result = e.message }
        result = result instanceof Map ? result.collect{"$it.key: $it.value"}.join('\n') :
                 result instanceof Iterable ? result.join('\n') : result
        render """${g.form(action:'eval',method:'POST') {
            "${g.textArea(name:'script',value:params.script,cols:80,rows:10)}${g.submitButton(name:'Submit')}"}}
            <hr/><pre>${result}</pre>"""
    }