Custom Freemarker configuration

Advanced usage of Freemarker

Freemarker is the templating language we are using for rendering views. It can do a lot of cool stuff, and you should refer to http://freemarker.org/ to learn more.

The Freemarker Configuration object can be accessed via your application TemplateEngineFreemarker singleton. According to the FreeMarker documentation, the configuration will be thread-safe once all settings have been set via a safe publication technique. Therefore, consider modifying it only within an extended NinjaDefault class, during the framework start.

package conf;

public class Ninja extends NinjaDefault {

	@Inject
	protected TemplateEngineFreemarker templateEngineFreemarker;

	@Override
	public void onFrameworkStart() {
		super.onFrameworkStart();

		Configuration freemarkerConfiguration = templateEngineFreemarker.getConfiguration();
		...
	}

}

Custom functions - The Java way

While you can access the Freemarker Configuration object, you can add your own custom functions using Java code:

freemarkerConfiguration.setSharedVariable("upper", new TemplateMethodModelEx() {

	@Override
	public Object exec(List args) throws TemplateModelException {
		return new SimpleScalar(args.get(0).toString().toUpperCase());
	}
});

And in your template:

${upper('Make me upper case.')}

Custom functions - The Ftl way

But for templating purpose, you can also do it by defining sets of macro functions in separate .ftl.html files.

<#macro bold>
	<b><#nested /></b>
</#macro>

And in your template :

<#import "../layout/functions.ftl.html" as f> 
<@f.bold>Make me bold</@f.bold>

This last way should help you making reusable macros when using one or another HTML/CSS framework.