From Groovy 2.3, there is a new innovate template engine. Is a very nice feature in the server side, but what happens in the client side? You can’t use that templates in javascript, and you have to call server to render templates. But, wait, mmm…​ sure? No! Grooscript to the rescue.

What do you need?

You have to use grooscript gradle plugin, so you need also gradle. To get more info about the plugin you can read getting started guide. Let’s take a look to build.gradle file:

plugins {
  id "org.grooscript.conversion" version "1.2.3" (1)

task templates(type: org.grooscript.gradle.TemplatesTask) { (2)
    templatesPath = 'tpls' (3)
    templates = ['one.gtpl', 'three.gtpl'] (4)
    destinationFile = 'js/Templates.js' (5)
1 Add grooscript gradle plugin
2 Create a templates task
3 Folder where templates are
4 Templates you want to include in the javascript file
5 Javascript file with the groovy templates

Each time you run this task templates, groovy templates ('one.gtpl' and 'three.gtpl') will be converted to javascript, and are available in the file js/Templates.js.

Using it

To use this file in your javascript project, you have to add grooscript.js and grooscript-tools.js as dependencies. You can get that files from bower package or download from website. Now, in javascript you can use the groovy templates with any javascript object, for example we have this two templates:

h1 model.title
ul {
	model.books.each {
		p "Title: ${it.title} Author: ${}"

def groovyTimes = { number ->
	'Groovy' * number

model.each {
	p groovyTimes(it)

For apply the template with a model, just call Templates.applyTemplate(templateName, data); to get html code.

Unresolved directive in templating.adoc - include::../src/test/resources/gs/index.html[]

We will get in console:

	<p>Title: Book 1 Author: Author 1</p>
	<p>Title: Book 2 Author: Author 2</p>
You can use groovy code supported by grooscript in your groovy templates.

Don’t forget

  • You can’t use import’s or any code out of the template.

  • You can use other templates with include template: 'one.gtpl', but you can’t include any other files.

  • Internationalization not supported.

  • You have to use model to access the model data.

  • Generated html code doesn’t have any TAB or CR.

  • Available groovy templates functions: yield, comment, yieldUnescaped, newLine and include(template).


Use groovy, use everywhere, even in your templates in the client side. Don’t repeat yourself, use the same templates in the client and in the server. You can tests your client templates in the server side, yeah!

You can explore deeper in plugin tasks to discover more things. For example you can type check your groovy templates, or to have a daemon listening changes in groovy templates and generating javascript file itself.

Groovy templates are very fast in the server, but also in the client. Apply templates are faster that handlebar’s, but only first executions, later handlebar’s are faster because they optimize / cache them.

Please, if you have comments, suggestions, problems,…​ don’t hesitate to contact me at, or open an issue or feature in Github. This is an open source project and your feedback is more than welcome to improve it. More guides come in the future, also can find more documentation in grooscript site.