Jtalk

By Nicolas Petton petton.nicolas@gmail.com

Jtalk is an implementation of the Smalltalk language that runs on top of the JavaScript runtime. It is designed to make client-side development faster and easier.

Overview

Jtalk is written in itself, including the parser and compiler. Jtalk compiles into efficient JavaScript, mapping one-to-one with the equivalent JavaScript. There is no interpretation at runtime.

Some highlights:

• Jtalk features an IDE with a Class browser, Workspace, Transcript, a ReferencesBrowser supporting senders/implementors and class references, basic Inspector and even a beginning of a Debugger and a unit TestRunner.
• Pharo Smalltalk is considered as the reference implementation.
• Jtalk includes a canvas to generate HTML, like Seaside
• Jtalk can use Javascript libraries and the current IDE is built on jQuery
• You can inline Javascript code and there are many ways to interact between Jtalk and Javascript

How to commit changes from the web-based IDE

The Jtalk class browser is able to commit changes to disk. The "commit category" button will send a PUT request with the JS code of all classes in the selected class category in a file named js/CATEGORY.js and also send the corresponding .st files to the st directory.

The easiest way to enable committing is probably to setup a webdav with Apache.

The following steps explain how to setup a webdav for Jtalk with Debian, but the setup on OSX and other Linux distros should be similar.

Install Apache and enable the dav module

apt-get install apache2
a2enmod dav
a2enmod dav_fs

Create a password for the webdav

htpasswd -c /etc/apache2/htpasswd-webdav USERNAME

Setup the webdav for Jtalk

Add the following lines to the default vhost (in /etc/apache2/sites-available/default):

Alias /jtalk/ "/path/to/jtalk/"
    <Directory "/path/to/jtalk/">
        Options Indexes MultiViews FollowSymLinks
    DirectoryIndex index.html
    AllowOverride None
	    Order allow,deny
    allow from all

    Dav on

    AuthType Basic
        AuthName "jtalk"
        AuthUserFile /etc/apache2/htpasswd-webdav
    <LimitExcept GET OPTIONS>
            Require valid-user
    </LimitExcept>

    </Directory>

Make sure the group www-data has required rights to modify files in the webdav directory.

Restart Apache

/etc/init.d/apache2 restart

License

Jtalk is released under the MIT license. All contributions made for inclusion are considered to be under MIT.

More infos

More on the project page