Mittwoch, 25. Mai 2011

RemoteRunner for JTalk Server

As announced in an earlier blog-post, i implemented a RemoteRunner for the jtalk-server (based on the jtalk-project). It's very simple: if you implement a Method runRemote in your class, e.g. RemoteTest, then by executing:
RemoteRunner new runClass: RemoteTest
will execute the Smalltalk-Code implemented in the runRemote-Method on the server. The example prints out the date and time of the server.
To see how the results can be transferred back to the client-caller, just look at the example-class.
The jtalk.js on the server-side is exactly the same as the one on the client-side. So if you make changes, don't forget to press the button "Export & Save JTalk to DB".
If you like to play around with this new feature and you played around with jtalk-server before (and pressed the save-button), you need to reset the jtalk.js by pressing the button. This is because, the jtalk.js will be saved to the database for every user (identified by his/ her google-id). So changes made to the jtalk.js, which is located in the server-filesystem won't get executed, because on startup (page-load) a jtalk.js in the DB, associated with the current google-user, has priority.
The JVM of the JDK/ JRE 6 is packaged with a ScriptEngine for executing Javascript. This feature is currently not supported on the Google App Engine, so i needed to use the "external" Rhino-jar, and a slightly different mechanism. Here is some work needed on optimizing the server-execution. So, the jtalk.js on the server should get reduced to the classes that are needed on the server (no canvas etc.) and most imported, the precompiled jtalk.js should get persisted somehow. Currently the complete javascript-source of the Smalltalk-System is executed/ interpreted for every call on the server.
But the next step will be to use the GAE persistence-layer via java-calls from Smalltalk/ Javascript to the google-api. Calling java is already possible and i think this is where the fun begins ...

Dienstag, 10. Mai 2011

Smalltalk & Java: JTalk Server

Recently I was playing around with the amazing Jtalk Project. It's a Smalltalk-System running on top of Javascript - completly in your browser!
I have some far away goals for software development in mind:
1. develop Software from within a Browser
2. use Smalltalk as primary Language, because it's the best programming language ever :-)
3. have interfaces to the JVM, so i can use sophisticated and reliable frameworks
There are a few Projects i know of, that address the goal of integrating Smalltalk with the Java (redline, Athena) but none of them seems to be very stable.
Now i found out, that Jtalk could do the job! So i spend a little time to set up a project hosted on the google app engine that serves as a development home for Jtalk Projects, where you have the possibility to save the current "state" (the complete source) to a database and resume developing anywhere anytime. You need a google-account to use it.
In this thread on the jtalk-discussion-group, i showed that it is possible to run Jtalk on top of the JVM and execute Smalltalk-Code. The way back - calling Java-Classes from Smalltalk is shown also.
At the moment my project only uses Jtalk on the client-side, the next step will be, make it run on the server-side.
Here's the link to where you can test JTalk Server: and the code is here:
Any help, tipps or comments are welcome!