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Jemplate - JavaScript Templating with Template Toolkit


Jemplate - JavaScript Templating with Template Toolkit


    var data = Ajax.get('url/data.json');
    var elem = document.getElementById('some-div');
    elem.innerHTML = Jemplate.process('my-template.html', data);


    var data = Ajax.get('url/data.json');
    var elem = document.getElementById('some-div');
    Jemplate.process('my-template.html', data, elem);

or simply:

    Jemplate.process('my-template.html', 'url/data.json', '#some-div');

or, with jQuery.js:

    jQuery.getJSON("url/data.json", function(data) {
        Jemplate.process('my-template.html', data, '#some-div');

From the commandline:

    jemplate --runtime --compile path/to/jemplate/directory/ > jemplate.js


Jemplate is a templating framework for JavaScript that is built over Perl's Template Toolkit (TT2).

Jemplate parses TT2 templates using the TT2 Perl framework, but with a twist. Instead of compiling the templates into Perl code, it compiles them into JavaScript.

Jemplate then provides a JavaScript runtime module for processing the template code. Presto, we have full featured JavaScript templating language!

Combined with JSON and xmlHttpRequest, Jemplate provides a really simple and powerful way to do Ajax stuff.


Jemplate comes with a command line tool call jemplate that you use to precompile your templates into a JavaScript file. For example if you have a template directory called templates that contains:

    > ls templates/

You might run this command:

    > jemplate --compile template/* > js/jemplates.js

This will compile all the templates into one JavaScript file.

You also need to generate the Jemplate runtime.

    > jemplate --runtime > js/Jemplate.js

Now all you need to do is include these two files in your HTML:

    <script src="js/Jemplate.js" type="text/javascript"></script>
    <script src="js/jemplates.js" type="text/javascript"></script>

Now you have Jemplate support for these templates in your HTML document.


The Jemplate.js JavaScript runtime module has the following API method:

Jemplate.process(template-name, data, target);

The template-name is a string like 'body.html' that is the name of the top level template that you wish to process.

The optional data specifies the data object to be used by the templates. It can be an object, a function or a url. If it is an object, it is used directly. If it is a function, the function is called and the returned object is used. If it is a url, an asynchronous <Ajax.get> is performed. The result is expected to be a JSON string, which gets turned into an object.

The optional target can be an HTMLElement reference, a function or a string beginning with a # char. If the target is omitted, the template result is returned. If it is a function, the function is called with the result. If it is a string, the string is used as an id to find an HTMLElement.

If an HTMLElement is used (by id or directly) then the innerHTML property is set to the template processing result.

The Perl module has the following public class methods, although you won't likely need to use them directly. Normally, you just use the jemplate command line tool.


Take a list of template file paths and compile them into a module of functions. Returns the text of the module.

Jemplate->compile_template_content($content, $template_name);

Compile one template whose content is in memory. You must provide a unique template name. Returns the JavaScript text result of the compilation.

Jemplate->compile_module($module_path, \@template_file_paths);

Similar to `compile_template_files`, but prints to result to the $module_path. Returns 1 if successful, undef if error.

Jemplate->compile_module_cached($module_path, \@template_file_paths);

Similar to `compile_module`, but only compiles if one of the templates is newer than the module. Returns 1 if successful compile, 0 if no compile due to cache, undef if error.


Jemplate comes with builtin Ajax and JSON support.

Ajax.get(url, [callback]);

Does a GET operation to the url.

If a callback is provided, the operation is asynchronous, and the data is passed to the callback. Otherwise, the operation is synchronous and the data is returned., data, [callback]);

Does a POST operation to the url.

Same callback rules as get apply.


Return the JSON serialization of an object.


Turns a JSON string into an object and returns the object.


The goal of Jemplate is to support all of the Template Toolkit features that can possibly be supported.

Jemplate now supports almost all the TT directives, including:

  * Plain text
  * [% [GET] variable %]
  * [% CALL variable %]
  * [% [SET] variable = value %]
  * [% DEFAULT variable = value ... %]
  * [% INCLUDE [arguments] %]
  * [% PROCESS [arguments] %]
  * [% BLOCK name %]
  * [% FILTER filter %] text... [% END %]
  * [% JAVASCRIPT %] code... [% END %]
  * [% WRAPPER template [variable = value ...] %]
  * [% IF condition %]
  * [% ELSIF condition %]
  * [% ELSE %]
  * [% SWITCH variable %]
  * [% CASE [{value|DEFAULT}] %]
  * [% FOR x = y %]
  * [% WHILE expression %]
  * [% RETURN %]
  * [% THROW type message %]
  * [% STOP %]
  * [% NEXT %]
  * [% LAST %]
  * [% CLEAR %]
  * [%# this is a comment %]
  * [% MACRO name(param1, param2) BLOCK %] ... [% END %]

ALL of the string virtual functions are supported.

ALL of the array virtual functions are supported:

ALL of the hash virtual functions are supported:

MANY of the standard filters are implemented.

The remaining features will be added very soon. See the DESIGN document in the distro for a list of all features and their progress.


Tested successfully in:

    * Firefox Mac/Win32/Linux
    * IE 6.0
    * Safari
    * Opera
    * Konqueror

All tests run 100% successful in the above browsers.


The bleeding edge code is available via Git at git://

You can run the runtime tests directly from or from the corresponding CPAN or JSAN directories.

Jemplate development is being discussed at irc://

If you want a committer bit, just ask ingy on the irc channel.


This module is only possible because of Andy Wardley's mighty Template Toolkit. Thanks Andy. I will gladly give you half of any beers I receive for this work. (As long as you are in the same room when I'm drinking them ;)


Ingy döt Net <>

(Note: I had to list myself first so that this line would go into META.yml)

Jemplate is truly a community authored project:

Ingy döt Net <>

Tatsuhiko Miyagawa <>

Yann Kerherve <>

David Davis <>

Cory Bennett <>

Cees Hek <>

Christian Hansen

David A. Coffey <>

Robert Krimen <>

Nickolay Platonov <>


Copyright (c) 2006-2014. Ingy döt Net.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.