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Cannot use Ruby Math library with Opal

Is there a way to use the ruby Math library in Opal ?

I got the following error message Uncaught NameError: uninitialized constant Object::Math when using Math::PI in my ruby method.

The ruby code :

class Numeric
  def degrees
    self * Math::PI / 180 
  end
end

The generated javascript by Opal :

/* Generated by Opal 0.6.3 */
(function($opal) {
  var self = $opal.top, $scope = $opal, nil = $opal.nil, $breaker = $opal.breaker, $slice = $opal.slice, $klass = $opal.klass;

  $opal.add_stubs(['$/', '$*']);
  return (function($base, $super) {
    function $Numeric(){};
    var self = $Numeric = $klass($base, $super, 'Numeric', $Numeric);

    var def = self._proto, $scope = self._scope;

    return (def.$degrees = function() {
      var $a, $b, self = this;

      return self['$*']((($a = ((($b = $scope.Math) == null ? $opal.cm('Math') : $b))._scope).PI == null ? $a.cm('PI') : $a.PI))['$/'](180);
    }, nil) && 'degrees'
  })(self, null)
})(Opal);

//# sourceMappingURL=/__opal_source_maps__/game_engine/numeric.js.map
;

Thanks ;)

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Porting wxPython to SWT/JFace

I use some nice controls/widgets in a simple wxPython app I developed taking inspiration from the sample demo. Call it my prototype.

I am now ready to migrate my prototype to Java/SWT.

Some controls are just not there.. or.. at least.. I could not find them.

Is there anything else in the FOSS world of SWT apart from the usual:

• SWT/JFace
• Nebula
• Opal

For a while I did not know about Nebula nor Opal at all. Now I do. At least you know I have done some legwork before coming here. Could it be that I am still oblivious to some fundamental set of extensions to the core SWT?

What I am doing right now is building a table, on the left - controls I use from wxPython, on the right - equivalent controls I'll use in Java/SWT.

The right column still has some gaping blanks..

Opal is completely broken?

I've been totally unsuccessful in getting Opal to work.

When I try to embed it in a Sinatra server using the tutorial here or the example code here, I get undefined method 'source_maps' for #<Opal::Server:0x8b11540>. When I use the updated code linked at the bottom of this post, I get uninitialized constant Opal::Sprockets::SourceMapHeaderPatch.

So, I abandon Sinatra and try using Opal in a Rack app instead, using their own example here. And I get a totally blank webpage.

Finally, I follow the tutorial here to the letter, and again all I get is a blank page in my browser.

So, what am I doing wrong? Or is Opal really as broken as it appears?

(oh, and that's not even mentioning the two serious out-of-bounds bugs in the rescue block in parse() in opal/parser.rb that completely kill any chance of debugging an error)

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I am working on a project that handles multiple jQuery events in succession using the opal-jquery wrapper. jQuery has very effective callback functionality and I am wondering if it is possible to do this in pure ruby with Opal.

Opal rails not able to compile source at runtime

I am trying to compile ruby source at run time in a browser. Earlier I used opal version 0.6.3 in which I get compile method and used to compile my source at run time in a javascript. But there are some problem with opal 0.6.3 so I want to upgrade it to 0.7.0 or higher. For this I use opal-rails gem but now I am no longer able to compile my ruby source at run time via javascript as compile method is no longer available.

Requests for a form that submits through ajax multiply with each subsequent submit

I have a form that makes an ajax request, the problem is that every time I click on it, the amount of times it makes that request multiplies.

Now I'm sure it's because of the way I've set up submit-intercept but I don't know how else to do it whilst still encapsulating it as a single component.

I'm using react as my view layer and I've attached a function that contains code to intercept the request and this function is called in both the afterMount callback and the after_update callback; if I don't do this then either the form submit is never intercepted or it only intercepts it once and then just does a normal submit.

Now obviously it's multiplying because those events fire and add an extra submit-handler.

I'm using opal and react.rb so the code might look a little odd.

Here's my function that intercepts the submit action on the form

def set_up_login_form
    puts 'setting up form'
    login_form = Element["#login_form"]
    login_form.on :submit do |event|
        unless login_state == :processing
            event.prevent_default
            username = login_form.find('#username').value
            password = login_form.find('#password').value
            login!
            self.username = username
            self.handle_login_submit({username: username , password: password})
        end 
    end
end

Here are my call backs:

after_mount do
    fix_button #untill materialize.js gets fixed
    set_up_login_form
end

after_update do
    set_up_login_form
end

I was able to reduce the amount of requests made by checking if the component state was already in the middle of a request, whilst this doesn't reduce the amount of submit handlers being added it does stop a good amount from doing anything, but it doesn't stop the actual multiplying of handlers being added.

Can't create variable on base object in 'self.included' hook in Opal

It's as the question title says, I have an included hook in a module:

def self.included(base)
    puts 'included'
    base.extend API
end

My API requires certain variables on the object to exists but none of them are being created.

I've tried:

1. base.variable_name = []
2. %x|#{base}.variable_name = []|
3. base.instance_variable_set(:@variable_name,[])
4. base.instance_exec{@variable_name = []}
5. 1-2 inside of base.instance_exec but using self instead of base

Yet none of them work, the console just complains that variable_name= doesn't exist.

What.the.hell?

How do I get the variable to exist on the base object inside of the included hook?