[IronPython] IronPython to JavaScript
Jimmy Schementi
Jimmy.Schementi at microsoft.com
Wed Jan 14 20:08:22 CET 2009
A MINIMAL reproduction of the error would be appropriate =)
> -----Original Message-----
> From: users-bounces at lists.ironpython.com [mailto:users-
> bounces at lists.ironpython.com] On Behalf Of Kristian Jaksch
> Sent: Wednesday, January 14, 2009 4:15 AM
> To: Discussion of IronPython
> Subject: Re: [IronPython] IronPython to JavaScript
>
> Thanks again for the reply.
>
> I must be getting something seriously wrong. I did what you said and I
> don't get any Javascript error but I still get the same error as
> before from Ironpython:
>
> "SystemError: Object reference not set to an instance of an object."
>
> I looked at the source code of your Web IDE and tried to understand
> how you did it there. You are hooking up a button click with the
> SetExample() function and that works just fine but if I try to call
> the SetExample() directly from the "_method()" function in the
> RefreshExamples class, then I get the same error as above. Below I
> show what I mean (it's your code a bit modified):
>
>
> setCode = ScriptableEvent()
> load = Load()
>
>
> def SetExample(name):
> args = ScriptableEventArgs()
> args.code = 'TESTING'
> setCode.OnEvent(args) #SystemError: Object reference not set to
> an instance of an object.
>
>
> class RefreshExamples(Scriptable):
> def _method(self):
> SetExample('browserDOM') #THIS DOESN'T WORK (It makes the
> call but gives the error above)
>
>
> refresh = RefreshExamples()
>
> HtmlPage.RegisterScriptableObject("codeChange", codeChange)
> HtmlPage.RegisterScriptableObject("refresh", refresh)
> HtmlPage.RegisterScriptableObject("load", load)
> HtmlPage.RegisterScriptableObject("setCode", setCode)
>
> # Default example
> HtmlPage.Document.code.value = examples.browserDOM
>
> root = Canvas()
> refresh._method()
>
>
> Application.Current.RootVisual = root
>
>
> Have I misunderstood this completely or shouldn't it be possible to
> directly call the SetExample()? Please bear in mind that I've only
> been programming Ironpython a couple of months :-)
>
> Mustn't these errors only depend on IronPython and have nothing to do
> with the JavaScript? I mean, first is the Silverlight app built, and
> this error occurs at that time so Javascript can't have any part in
> the errors?
>
> I know it's much to ask for but would it be possible for me to send
> you the minimalistic test website I have so you maybe can have a quick
> look at it? Or if you maybe have a as small as possible project I can
> have a look at.
>
> Again, thanks for all your help!
>
>
>
> 2009/1/14 Michael Foord <fuzzyman at voidspace.org.uk>:
> > Ahhh... there is a detail I missed out in that article. You can only
> hook up
> > the Javascript function after the Silverlight control has loaded.
> This is
> > *possibly* the cause of your problems.
> >
> > I do the hooking up in an onload function:
> >
> >
> > function onload() {
> > control =
> document.getElementById('SilverlightPlugin');
> > control.Content.setCode.Event = setCode;
> > }
> >
> > You pass this function in the online parameter in the Silverlight
> object
> > element:
> >
> > <object id="SilverlightPlugin"
> > data="data:application/x-silverlight," type="application/x-
> silverlight-2"
> > width="450" height="540">
> > <param name="source" value="app.xap"/>
> > <param name="onerror" value="onSilverlightError" />
> > <param name="onload" value="onload" />
> >
> > Hopefully this sorts out the problem for you.
> >
> > Michael Foord
> >
> > Kristian Jaksch wrote:
> >>
> >> Thanks for the reply!
> >>
> >> No, I can't get it to work with Javascript either. I added the
> script
> >> below to my page:
> >>
> >> <script type="text/javascript">
> >> function some_function(sender, args) {
> >> value = args.val;
> >> alert(value);
> >> }
> >>
> >> control = document.getElementById("sl2");
> >> control.Content.event.Event = some_function; // THIS
> >> LINE GIVES AN ERROR
> >> </script>
> >>
> >> I'm not sure about the exact translation of the error message (It's
> in
> >> swedish) but it's something like:
> >>
> >> "Error: Invalid pointer"
> >>
> >> I guess it has something to do with the error I receive in my
> "app.py"
> >> file as I described previously.
> >>
> >> I made a minimal app.py file to test it again but I still receive
> the
> >> same error. This file also test to get a string from Javascript to
> >> Ironpython and that works just fine. Below is my complete file:
> >>
> >>
> >> import clr, sys
> >>
> >> clr.AddReferenceToFile("Scriptable.dll")
> >>
> >> from System.Windows import Application
> >> from System.Windows.Browser import *
> >> from System.Windows.Controls import *
> >> from System.Windows import Input
> >> from Scriptable import *
> >>
> >>
> >> class GetFromEditor(ScriptableForString):
> >> def _method(self, string):
> >> root.message.Text = string
> >> #return new_string
> >>
> >> GetFromEditor = GetFromEditor()
> >>
> >> root = Application.Current.LoadRootVisual(UserControl(), "app.xaml")
> >>
> >> HtmlPage.RegisterScriptableObject("GetFromEditor", GetFromEditor)
> >>
> >>
> >> event = ScriptableEvent()
> >>
> >> # This must also be registered
> >> HtmlPage.RegisterScriptableObject("event", event)
> >>
> >> args = ScriptableEventArgs()
> >> args.val = 'some string'
> >> event.OnEvent(args)
> >>
> >>
> >> It must be something I'm missing but I just can't see what it could
> >> be. Do you know of any good example were this approach is used?
> >>
> >> Thanks again!
> >>
> >>
> >> 2009/1/12 Michael Foord <fuzzyman at voidspace.org.uk>:
> >>
> >>>
> >>> xkrja wrote:
> >>>
> >>>>
> >>>> I'm trying to call javascript from IronPython (via Silverlight 2)
> but I
> >>>> can'
> >>>> get it to work properly. I looked at this example:
> >>>>
> >>>>
> http://www.voidspace.org.uk/ironpython/silverlight/scriptable.shtml#id1
> 0
> >>>>
> http://www.voidspace.org.uk/ironpython/silverlight/scriptable.shtml#id1
> 0
> >>>> It's explained very clearly but when I try to run my code I get a
> System
> >>>> Error:
> >>>>
> >>>> SystemError: Object reference not set to an instance of an object.
> >>>>
> >>>> I just inserted the lines of code found on the example page in my
> >>>> IronPyton
> >>>> code:
> >>>>
> >>>> event = ScriptableEvent()
> >>>>
> >>>> # This must also be registered
> >>>> HtmlPage.RegisterScriptableObject("event", event)
> >>>>
> >>>> args = ScriptableEventArgs()
> >>>> args.val = 'some string'
> >>>> event.OnEvent(args) #This gives me a System Error
> >>>>
> >>>> I create a C# .dll as explained in the example and add a reference
> to
> >>>> it.
> >>>> The source is below:
> >>>>
> >>>> using System;
> >>>> using System.Windows.Browser;
> >>>>
> >>>> namespace Scriptable
> >>>> {
> >>>>
> >>>> [ScriptableTypeAttribute]
> >>>> public class ScriptableForString
> >>>> {
> >>>> [ScriptableMemberAttribute]
> >>>> public string method(string value)
> >>>> { return this._method(value); }
> >>>>
> >>>> public virtual string _method(string value)
> >>>> { return "override me"; }
> >>>> }
> >>>>
> >>>> [ScriptableType]
> >>>> public class ScriptableEvent
> >>>> {
> >>>> [ScriptableMember]
> >>>> public event EventHandler Event;
> >>>>
> >>>> public virtual void OnEvent(ScriptableEventArgs e)
> >>>> {
> >>>> Event(this, e);
> >>>> }
> >>>> }
> >>>>
> >>>> [ScriptableTypeAttribute]
> >>>> public class ScriptableEventArgs : EventArgs
> >>>> {
> >>>> private string _val;
> >>>>
> >>>> [ScriptableMemberAttribute]
> >>>> public string val
> >>>> {
> >>>> get { return _val; }
> >>>> set { _val = value; }
> >>>> }
> >>>> }
> >>>> }
> >>>>
> >>>> Can anyone explain what I'm doing wrong?
> >>>> Thanks for any help!
> >>>>
> >>>>
> >>>>
> >>>
> >>> Hmmm... do you have any Javascript hooking up to the event? If you
> don't,
> >>> try hooking up to it and see if it makes any difference.
> >>>
> >>> The same code works for me. :-)
> >>>
> >>> Michael
> >>>
> >>> --
> >>> http://www.ironpythoninaction.com/
> >>> http://www.voidspace.org.uk/blog
> >>>
> >>>
> >>> _______________________________________________
> >>> Users mailing list
> >>> Users at lists.ironpython.com
> >>> http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
> >>>
> >>>
> >>
> >> _______________________________________________
> >> Users mailing list
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> >> http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
> >>
> >
> >
> > --
> > http://www.ironpythoninaction.com/
> > http://www.voidspace.org.uk/blog
> >
> >
> > _______________________________________________
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> > Users at lists.ironpython.com
> > http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
> >
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