Handlebars.java is a Java implementation of Mustache. You can use Handlebars.java in any Java environment, but especially in web applications that make heavy use of JavaScript.

So, what make Handlebars.java special for web development?

Beside Handlebars.java is a multi-purpose template engine, one of the reason that makes Handlebars.java special, is that you can use the same template engine in the browser.

• Mustache.js
• Hogan.js
• Handlebars.js

Of course that Handlebars.js is what makes more sense to use, but you can also choose between any other existing implementations of Mustache.

Getting Mustache

The best way of getting started is by reading the Mustache documentation. You will find it very easy to follow and understand.

Then you might want to read the Handlebars.js documentation for a better understanding of how Handlebars.js extends Mustache through the use of helpers.

Hello Handlebars.java!

Handlebars handlebars = new Handlebars();
Template template = handlebars.compileInline("Hello {{this}}!");
System.out.println(template.apply("Handlebars.java"));

Print out:

Hello Handlebars.java!

Mustache is very simply template engine with just a few constructions. In the example above, "{{this}}" get resolved to "Handlebars.java".

Built-in helpers:

• with

  The with helper let you switch/change the current context to something else. For example:

  Model:

  {
    title: {
      story: {
        name: "Handlebars.java rocks!"
      }
    }
  }
  

  Template:

  Support by: Handlebars.js

  <h1>{{title}}</h1>
  {{#with story}}
    <span>{{name}}</span>
  {{/with}}
  

  Or in plain Mustache:

  Support by: Handlebars.js Mustache.js Hogan.js

  <h1>{{title}}</h1>
  {{#story}}
    <span>{{name}}</span>
  {{/story}}
  

• each

  The each helper let you iterate over collections, arrays and objects. For example:

  Model:

  {
    blogs: [
      title: {
        story: {
          name: "Handlebars.java rocks!"
        }
      }
    ]
  }
  

  Template:

  Support by: Handlebars.js

  {{#each blogs}}
    <h1>{{title}}</h1>
    {{#with story}}
      <span>{{name}}</span>
    {{/with}}
  {{/each}}
  

  Or in plain Mustache:

  Support by: Handlebars.js Mustache.js Hogan.js

  {{#blogs}}
    <h1>{{title}}</h1>
    {{#story}}
      <span>{{name}}</span>
    {{/story}}
  {{/blogs}}
  

• if

  The if helper evaluate a context value as true. For example:

  Template:

  Support by: Handlebars.js

  Is Active?
  {{#if active}}
    Yes
  {{/if}}
  

  Or in plain Mustache:

  Support by: Handlebars.js Mustache.js Hogan.js

  Is Active?
  {{#active}}
    Yes
  {{/active}}
  

  You can add an elsebranch using the else keyword or the ^ character:

  Template:

  Support by: Handlebars.js

  Is Active?
  {{#if active}}
    Yes
  {{else}}
    No
  {{/if}}
  

  Template:

  Support by: Handlebars.js

  Is Active?
  {{#if active}}
    Yes
  {{^}}
    No
  {{/if}}
  

• unless

  The unless helper evaluate a context value as false. For example:

  Template:

  Support by: Handlebars.js

  Is Active?
  {{#unless active}}
    No
  {{/unless}}
  

  Or in plain Mustache:

  Support by: Handlebars.js Mustache.js Hogan.js

  Is Active?
  {{^active}}
    No
  {{/active}}
  

Want to contribute?

• Fork the project on Github.
• Create an issue or fix one from the issues list.
• Share your ideas or ask questions on mailing list - don't hesitate to write a reply - that helps us improve javadocs/FAQ.
• If you miss a particular feature - browse or ask on the mailing list - don't hesitate to write a reply, show us a sample code and describe the problem.
• Write a blog post about how you use or extend Handlebars.java.
• Please suggest changes to javadoc/exception messages when you find something unclear.
• If you have problems with documentation, find it non intuitive or hard to follow - let us know about it, we'll try to make it better according to your suggestions. Any constructive critique is greatly appreciated. Don't forget that this is an open source project developed and documented in spare time.

Thank you, for reading the Handlebars.java blog.