wicket-mustache

Provides a specialized panel and some related utilities that enables users to work with Mustache and Apache Wicket.

Current build status:

wicket-mustache dependes on mustache.java.

Documentation:

• Mustache.js manual
• Mustache.java manual
• Passes all of the mustache specification tests modulo whitespace differences

Add maven dependency:

<dependency>
  <groupId>de.agilecoders.wicket.mustache</groupId>
  <artifactId>wicket-mustache</artifactId>
  <version>0.1.0</version>
</dependency>

Installation:

    /**
     * @see org.apache.wicket.Application#init()
     */
    @Override
    public void init() {
        super.init();

        WicketMustache.install(this);
    }

Usage

Example template file:

{{#items}}
Name: {{name}}
Price: {{price}}
  {{#features}}
  Feature: {{description}}
  {{/features}}
{{/items}}

Might be powered by some backing code:

public class Context implements IScope {
  List<Item> items() {
    return Arrays.asList(
      new Item("Item 1", "$19.99", Arrays.asList(new Feature("New!"), new Feature("Awesome!"))),
      new Item("Item 2", "$29.99", Arrays.asList(new Feature("Old."), new Feature("Ugly.")))
    );
  }

  static class Item {
    Item(String name, String price, List<Feature> features) {
      this.name = name;
      this.price = price;
      this.features = features;
    }
    String name, price;
    List<Feature> features;
  }

  static class Feature {
    Feature(String description) {
       this.description = description;
    }
    String description;
  }
}

And would result in:

Name: Item 1
Price: $19.99
  Feature: New!
  Feature: Awesome!
Name: Item 2
Price: $29.99
  Feature: Old.
  Feature: Ugly.

Evaluation of the template proceeds serially. For instance, if you have blocking code within one of your callbacks you the system will pause while executing them:

static class Feature {
  Feature(String description) {
    this.description = description;
  }

  String description() throws InterruptedException {
    Thread.sleep(1000);
    return description;
  }
}

If you change description to return a Callable instead it will automatically be executed in a separate thread if you have provided an ExecutorService when you created your MustacheFactory.

Callable<String> description() throws InterruptedException {
  return new Callable<String>() {

    @Override
    public String call() throws Exception {
      Thread.sleep(1000);
      return description;
    }
  };
}

This enables scheduled tasks, streaming behavior and asynchronous i/o. Check out the samples module in order to see a complete end-to-end example:

package de.agilecoders.wicket;

import de.agilecoders.wicket.mustache.IScope;
import de.agilecoders.wicket.mustache.MustachePanel;
import org.apache.wicket.core.util.resource.PackageResourceStream;
import org.apache.wicket.markup.html.WebPage;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.LoadableDetachableModel;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.util.resource.IResourceStream;

import java.util.Arrays;
import java.util.List;

public class HomePage extends WebPage {
    private static final long serialVersionUID = 1L;

    public HomePage(final PageParameters parameters) {
        super(parameters);

        IModel<IScope> scopeModel = new LoadableDetachableModel<IScope>() {
            @Override
            public IScope load() {
                return new Example();
            }
        };

        add(new MustachePanel("template", scopeModel) {
            @Override
            protected IResourceStream newTemplateResourceStream() {
                return new PackageResourceStream(HomePage.class, "template.mustache");
            }
        });
    }

    public static class Example implements IScope {

        public List<Item> items() {
            return Arrays.asList(
                    new Item("Item 1", "$19.99", Arrays.asList(new Feature("New!"), new Feature("Awesome!"))),
                    new Item("Item 2", "$29.99", Arrays.asList(new Feature("Old."), new Feature("Ugly.")))
            );
        }

        static class Item {
            Item(String name, String price, List<Feature> features) {
                this.name = name;
                this.price = price;
                this.features = features;
            }

            String name, price;
            List<Feature> features;
        }

        static class Feature {
            Feature(String description) {
                this.description = description;
            }

            String description;
        }
    }
}

Client Side Rendering

If you want to render your mustache template on client side you have two options: ClientSideMustachePanel and LazyLoadingClientSideMustachePanel.

add(new ClientSideMustachePanel("template-client", scopeModel) {
    @Override
    protected IResourceStream newTemplateResourceStream() {
        return new PackageResourceStream(HomePage.class, "template.mustache");
    }
});

add(new LazyLoadingClientSideMustachePanel("template-lazy", scopeModel) {
    @Override
    protected IResourceStream newTemplateResourceStream() {
        return new PackageResourceStream(HomePage.class, "template.mustache");
    }

    @Override
    protected CharSequence loading() {
        return "please wait...";
    }

    @Override
    protected Duration delay() {
        return Duration.seconds(5);
    }
});