rubycocoa-talk

[Rubycocoa-talk] Calling Ruby from existing Cocoa App

[David <dba...@gm...>]

Hello.   I am looking into using Ruby to manipulate some data in my  
Cocoa-based application.  I found the excellent documentation written  
by Tom Burks but it is not detailed enough on how to add this  
functionality to an existing Cocoa app in XCode.

What I am looking for is the necessary changes needed to my project  
to allow my Cocoa app based on XCode 2.2 running on Tiger to call  
Ruby routines passing in NSArray objects with the minimum amount of  
changes to my project.


I assume I need to at least add the RubyCocoa framework.  After doing  
this and importing "RubyCocoa/RubyCocoa.h" I get an error:
/Library/Frameworks/RubyCocoa.framework/Headers/osx_ruby.h:21:20:  
error: config.h: No such file or directory

I also looked at the HybridLangApp sample but it is based on  
RBApplicationMain instead of NSApplicationMain.

Thanks for any assistance.

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[Tim B. <tim...@gm...>]

Hi David,

Thanks for your comments on the documentation.

I too have wanted to mix RubyCocoa into an existing application, but I
hadn't tried it until this evening, when I successfully converted one
of my pure Objective-C Cocoa projects to RubyCocoa.  Here's my story:

First I added the RubyCocoa framework to the project in Xcode. In my
case, I right-clicked on the project name in the Groups & Files panel
in Xcode, then selected Add->Existing Frameworks... and navigated to
/Library/Frameworks/RubyCocoa.framework.

Next I replaced the contents of main.m with the following, taken from
the RubyCocoa Xcode templates:
---
#import <RubyCocoa/RBRuntime.h>

int main(int argc, const char *argv[])
{
    return RBApplicationMain("rb_main.rb", argc, argv);
}
---
This is necessary to make sure that Ruby is properly initialized and
it also gives you a way to run some Ruby code when your  program
starts.   As far as I know, you *must* replace your main() to use
RubyCocoa, but you probably didn't have anything special there anyway
-- just a call to NSApplicationMain, which your converted app will
make with Ruby.

Then I added rb_main.rb to my project using Add->Existing Files... and
then finding and selecting one from a template-based RubyCocoa
application.  For reference, this short file contains the following
Ruby code:
---
require 'osx/cocoa'

def rb_main_init
  path =3D OSX::NSBundle.mainBundle.resourcePath.to_s
  rbfiles =3D Dir.entries(path).select {|x| /\.rb\z/ =3D~ x}
  rbfiles -=3D [ File.basename(__FILE__) ]
  rbfiles.each do |path|
    require( File.basename(path) )
    OSX::NSLog "require #{File.basename(path)}"
  end
end

if $0 =3D=3D __FILE__ then
  rb_main_init
  OSX.NSApplicationMain(0, nil)
end
---
It loads any ruby files in your application's resource directory and
then calls NSApplicationMain.

Then I built and tested my application.  Everything seemed to work
just as before, but now my formerly mild-mannered Objective-C program
can speak Ruby.

From here forward, you can add Ruby files to your application and know
that all inline code in them will get executed when rb_main_init loads
the files during startup.

In my case, I added a console object that I've been writing/debugging
that let's me run irb inside a Cocoa app.  Accessing my Objective-C
objects was a puzzle at first, but I managed to get to my top-level
document object (a game) from the NSDocumentController:
> game_controller =3D OSX::NSDocumentController.sharedDocumentController
> game =3D game_controller.documents.objectAtIndex(0)

From there, I could directly call the methods of my object from Ruby:
> game.start
> game.sendEvent_forPlayer(10, 0)
> game.stop

I'll test it more in the next few days, but as far as I can tell, the
transplant went smoothly.

Hope that helps,

Tim

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[Jonathan P. <jp...@dc...>]

On 31 Jan 2006, at 6:46, Tim Burks wrote:

>> game_controller = OSX::NSDocumentController.sharedDocumentController
>> game = game_controller.documents.objectAtIndex(0)
>
> From there, I could directly call the methods of my object from Ruby:
>> game.start
>> game.sendEvent_forPlayer(10, 0)
>> game.stop

The same should work in the other direction too: assuming you can get  
a reference in objc to one of your ruby objects, you should be able  
to call methods on it. e.g.:

In ruby:

   game.setRubyObject(someobj)

Then in objc:

   [rubyObject someMethod: anArgument];

.. assuming you've got an instance variable called 'rubyObject' of  
type 'id' that has a setter method like:

-(void)setRubyObject:(id)obj
{
    [obj retain];
    [rubyObject autorelease];
    rubyObject = obj;
}


Another, possibly simpler, solution is to define an ObjC class in Ruby:

   class Foo < OSX::NSObject
      # ...
      def myMethod(arg1)
        puts arg1
      end
   end

Then, in objc:

   Class fooClass = NSClassFromString(@"Foo");
   id fooInstance = [[fooClass alloc] init];
   [fooInstance myMethod: @"hello"];
[the above code is untested - I think the idea is right though]



I imagine there'll be various compiler warnings since there are no  
prototypes for the messages being sent to the 'id' variable type. An  
objc interface declaration should fix that.



Cheers,

Jonathan

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[David <dba...@gm...>]

I had came to this solution as well when testing and it does work.  I  
would have thought though that this could be encapsulated into an  
RBObject class so that you can hide some of this and do some sanity  
checks as well?  There is a initWithRubyObject in RBObject but would  
it be useful to have a initWithRubyObjectName?

I was also thinking that with XCode it should be possible to write a  
script that will read your ruby files and generate an objc interface  
file for them each time you build..  that would be cool..




> Another, possibly simpler, solution is to define an ObjC class in  
> Ruby:
>
>   class Foo < OSX::NSObject
>      # ...
>      def myMethod(arg1)
>        puts arg1
>      end
>   end
>
> Then, in objc:
>
>   Class fooClass = NSClassFromString(@"Foo");
>   id fooInstance = [[fooClass alloc] init];
>   [fooInstance myMethod: @"hello"];
> [the above code is untested - I think the idea is right though]
>
>
>
> I imagine there'll be various compiler warnings since there are no  
> prototypes for the messages being sent to the 'id' variable type.  
> An objc interface declaration should fix that.
>
>
>
> Cheers,
>
> Jonathan
>
>

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[Jonathan P. <jp...@dc...>]

On 31 Jan 2006, at 17:26, David wrote:

> I had came to this solution as well when testing and it does work.   
> I would have thought though that this could be encapsulated into an  
> RBObject class so that you can hide some of this and do some sanity  
> checks as well?  There is a initWithRubyObject in RBObject but  
> would it be useful to have a initWithRubyObjectName?

Can you give an example of how you'd like/expect things to work? I'm  
not quite clear on it yet.

> I was also thinking that with XCode it should be possible to write  
> a script that will read your ruby files and generate an objc  
> interface file for them each time you build..  that would be cool..

Certainly possible - although how useful it is depends on how broad  
your interface is going to be. If there are relatively few entry  
points into ruby then it's probably easy enough to keep two files up  
to date (as you would have to do anyway with a plain objc header and  
implementation).

Cheers,
Jonathan

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[David <dba...@gm...>]

 From my existing Cocoa app I would like to pass several NSArray's to  
Ruby, manipulate them in Ruby, serialize the arrays in JSON format,  
and return that data back to Cocoa.  Does this seem like a reasonable  
task for the RubyCocoa bridge?

I see ruby 1.8+ has a to_yaml method for objects but how do I produce  
JSON format for the arrays?

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[Jonathan P. <jp...@dc...>]

On 1 Feb 2006, at 18:51, David wrote:

> From my existing Cocoa app I would like to pass several NSArray's  
> to Ruby, manipulate them in Ruby, serialize the arrays in JSON  
> format, and return that data back to Cocoa.  Does this seem like a  
> reasonable task for the RubyCocoa bridge?
>
> I see ruby 1.8+ has a to_yaml method for objects but how do I  
> produce JSON format for the arrays?

Assuming you have an NSArray instance my_array in ruby, can you just do:

   manipulate(my_array.to_a).to_yaml

i.e., convert the NSArray to a real ruby Array, do some stuff on it,  
then convert that array to yaml/json?

Re: [Rubycocoa-talk] Calling Ruby from existing Cocoa App

[David <dba...@gm...>]

Thanks for the explanation..  I also spent some time investigating it =20=

last night (probably because I'm stubborn :) ) and was able to come =20
to a similar result.  I started an entry on the RubyCocoa Wiki so =20
that it will be easier for anybody in the future to not have to spend =20=

time figuring out what to do..  Feel free to edit it or add this info =20=

to your documentation..

The easier it is for a newby to get this stuff to work the more =20
people there will be using it.  I originally tried getting PyObjc to =20
work and even asked on the mailing list but never got a =20
straightforward answer on how to make the bridge transparent..  =20
especially as transparent as the Ruby-Obj-C bridge appears to be.. :) =20=

So now I'm using Ruby instead..

David

On Jan 31, 2006, at 12:46 AM, Tim Burks wrote:

> Hi David,
>
> Thanks for your comments on the documentation.
>
> I too have wanted to mix RubyCocoa into an existing application, but I
> hadn't tried it until this evening, when I successfully converted one
> of my pure Objective-C Cocoa projects to RubyCocoa.  Here's my story:
>
> First I added the RubyCocoa framework to the project in Xcode. In my
> case, I right-clicked on the project name in the Groups & Files panel
> in Xcode, then selected Add->Existing Frameworks... and navigated to
> /Library/Frameworks/RubyCocoa.framework.
>
> Next I replaced the contents of main.m with the following, taken from
> the RubyCocoa Xcode templates:
> ---
> #import <RubyCocoa/RBRuntime.h>
>
> int main(int argc, const char *argv[])
> {
>     return RBApplicationMain("rb_main.rb", argc, argv);
> }
> ---
> This is necessary to make sure that Ruby is properly initialized and
> it also gives you a way to run some Ruby code when your  program
> starts.   As far as I know, you *must* replace your main() to use
> RubyCocoa, but you probably didn't have anything special there anyway
> -- just a call to NSApplicationMain, which your converted app will
> make with Ruby.
>
> Then I added rb_main.rb to my project using Add->Existing Files... and
> then finding and selecting one from a template-based RubyCocoa
> application.  For reference, this short file contains the following
> Ruby code:
> ---
> require 'osx/cocoa'
>
> def rb_main_init
>   path =3D OSX::NSBundle.mainBundle.resourcePath.to_s
>   rbfiles =3D Dir.entries(path).select {|x| /\.rb\z/ =3D~ x}
>   rbfiles -=3D [ File.basename(__FILE__) ]
>   rbfiles.each do |path|
>     require( File.basename(path) )
>     OSX::NSLog "require #{File.basename(path)}"
>   end
> end
>
> if $0 =3D=3D __FILE__ then
>   rb_main_init
>   OSX.NSApplicationMain(0, nil)
> end
> ---
> It loads any ruby files in your application's resource directory and
> then calls NSApplicationMain.
>
> Then I built and tested my application.  Everything seemed to work
> just as before, but now my formerly mild-mannered Objective-C program
> can speak Ruby.
>
> =46rom here forward, you can add Ruby files to your application and =
know
> that all inline code in them will get executed when rb_main_init loads
> the files during startup.
>
> In my case, I added a console object that I've been writing/debugging
> that let's me run irb inside a Cocoa app.  Accessing my Objective-C
> objects was a puzzle at first, but I managed to get to my top-level
> document object (a game) from the NSDocumentController:
>> game_controller =3D =
OSX::NSDocumentController.sharedDocumentController
>> game =3D game_controller.documents.objectAtIndex(0)
>
> =46rom there, I could directly call the methods of my object from =
Ruby:
>> game.start
>> game.sendEvent_forPlayer(10, 0)
>> game.stop
>
> I'll test it more in the next few days, but as far as I can tell, the
> transplant went smoothly.
>
> Hope that helps,
>
> Tim
>
>
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