jython-users

[Jython-users] Re: Q : About Jython & Applet (i'm begginer -_-)

[D-Man <ds...@ri...>]

On Fri, Feb 02, 2001 at 09:47:53PM +0900, syKim wrote:
| 
| Thank you for your reply again..

You're welcome.

| 
| I tested that two way..
| 
| first : same your code.
| 
| second : I attached some code behind that like 
| 
| if __name__ == '__main__':
|     import pawt
|     pawt.test(HelloApplet(), size=(500, 120))

I'm not familiar with the "pawt" module.

| 
| I compiled that several ways.
| (just -w . or  --core -d or --core -d --jar HelloApplet.jar)
| 
| however, the applet doesn't work.
| (in addition, jython should have org folder with java files --> you can know if you test with appletviewer
|  then, I copied the folder from jython folder to testing folder.)
| 
| when I execute appletviewer, some error occured like that :
| 
| java.lang.NullPointerException 
| 
|     at org.python.core.PyJavaClass.lookup (PyJavaClass.java:39)
|     ...

In PyJavaClass.java, on line 39, the Jython runtime is trying to
dereference a null pointer.  I don't know right now what is causing
this.

| 
| hmm.. How can I solve this problem?
| 
| and, Is not exist another way to implement web-browser-based application with python? 

You could tell users to use the "Grail" browser ;-),  it can execute
"Python Applets".  The basic problem with web-browser-based
applications is your users (web browsers) must have the required
interpreter/libraries available.  Sun did a good job selling java, so
now all browsers include a java interpreter which allows them to run
java applets.  Browsers aren't including a python interpreter, which
makes it harder to run python code.  I would expect that, since Jython
is written entirely in Java, and it outputs java code that any JVM can
run stuff made with jython.  Now we just have to solve all the java
dependencies the browsers have.

I did a bit more testing:

I put my html file and the class files on a web server and tried to
load them.  I got NoClassDefFound errors for org/python/* classes.
Ok, so the jython.jar file is needed in the class path.  I ran jythonc
with the --jar and --all options.  This put my .class files and the
jython .class files nicely into a single jar file.  Trying again with
  codebase="myapplet"  in the html file (I named the jar file
  myapplet.jar).  Now I'm getting a
ClassFormatError: HelloApplet (Bad magic number)
error.  I think this is related to compiler/interpreter versions.

I have to do some work now, but I will try again later.

I'm cc'ing the list in case anyone else can shed some light on the
issue.

-D

[Jython-users] RE: Q : About Jython & Applet (i'm begginer -_-)

[syKim <re...@ne...>]
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==

[Jython-users] About grail..

[syKim <re...@ne...>]
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Re: [Jython-users] About grail..

[D-Man <ds...@ri...>]

On Sat, Feb 03, 2001 at 07:19:12AM +0900, syKim wrote:
| 
| -You could tell users to use the "Grail" browser ;-),  it can execute
| -"Python Applets".  The basic problem with web-browser-based
| -applications is your users (web browsers) must have the required
| -interpreter/libraries available.  Sun did a good job selling java, so
| -now all browsers include a java interpreter which allows them to run
| -java applets.  Browsers aren't including a python interpreter, which
| -makes it harder to run python code.  I would expect that, since Jython
| -is written entirely in Java, and it outputs java code that any JVM can
| -run stuff made with jython.  Now we just have to solve all the java
| -dependencies the browsers have.
| 
| I don't know both  "Grail" & python applets.
| 
| How it works?
| 
| How can I get more information about it?
| 

Grail is a web browser written in python.  You can find it on the
python web site, maybe in the Vaults of Parnassus, and I think it is
actually located on sourceforge (try http://grail.sourceforge.net).

I don't think it is being actively maintained anymore though.  Since
Grail is written in python, it was made with the ability to run python
applets.  I don't know if they would need to be put in a zip file or
what for the browser to get them. 

I think that using jython is the best solution for you since (almost)
everybody has a web browser that can run java applets.

-D

Re: [Jython-users] About grail..

[Mats W. <ma...@la...>]

 >
 >Grail is a web browser written in python.  You can find it on the
 >python web site, maybe in the Vaults of Parnassus, and I think it is
 >actually located on sourceforge (try http://grail.sourceforge.net).
 >
 >I don't think it is being actively maintained anymore though.  Since
 >Grail is written in python, it was made with the ability to run python
 >applets.  I don't know if they would need to be put in a zip file or
 >what for the browser to get them.

Grail was a CNRI special, made particularly to demonstrate one of
their particular concepts.  You can get it by following the links
on python.org, but be warned:  it's very fragile, and there are
no plans that I've heard of for anyone to fix it.  I played with
it for a while and concluded it was unusable.

Mats