[IronPython] Databinding a color in the datagrid in Silverlight

[Michael Foord]

On 09/02/2010 03:07, Dino Viehland wrote:
>
> On the IValueConverter side of things: I haven't debugged through this 
> but I have a guess as to what could be going on.  When we emit a type 
> via reflection I don't believe it's available via Type.GetType -- 
> which is the way types usually get loaded by name.  If you attach a 
> debugger I think you'd probably see an exception when trying to load 
> the type.
>
Thanks for the reply. Looks like an IValueConverter based solution is 
doomed to failure with IronPython and Silverlight.

> The usual solution for this would be to combine pre-compiled subtypes 
> and then save the generated type to disk and re-load it.  You need the 
> pre-compiled subtypes because you can't reference a transient assembly 
> (which our in-memory subtypes are) from a non-transient one.  But 
> that's not going to be immediately viable in Silverlight because the 
> pre-compiled type will be a desktop CLR type.  So you could use 
> pre-compiled types on the desktop and try to re-write the generated 
> assembly but it seems like that's never worked for anyone in the past.
>
> I have no clue on the PARSER_BAD_PROPERTY_VALUE error.
>

I asked this same question on Stack Overflow [1]  and someone said that 
you can't bind to a Color at all until Silverlight 4. Maybe that is the 
reason for the parser error. My colleague is suggesting that maybe we 
can use the new Silverlight 3 Feature "Element to Element Binding" [2], 
so I will look into that.

All the best,


Michael

[1] 
http://stackoverflow.com/questions/2224805/silverlight-databinding-with-ironpython-and-datagrid
[2] 
http://weblogs.asp.net/dwahlin/archive/2009/07/13/using-element-to-element-binding-for-tooltips-in-silverlight-3.aspx
>
> *From:* users-bounces at lists.ironpython.com 
> [mailto:users-bounces at lists.ironpython.com] *On Behalf Of *Michael Foord
> *Sent:* Monday, February 08, 2010 12:21 PM
> *To:* Discussion of IronPython
> *Subject:* [IronPython] Databinding a color in the datagrid in Silverlight
>
> Hello all,
>
> We've been successfully using clrtype with IronPython 2.6 and 
> Silverlight for databinding, based on the example provided by Lukáš:
>
> http://gui-at.blogspot.com/2009/11/inotifypropertychanged-and-databinding.html
>
> We create the binding when we create the datagrid columns programatically.
>
> Today I've been trying (and failing) to get a column in the grid show 
> different colors based on databinding.
>
> I've got the colored bubble *showing* in the grid, but can't get 
> databinding to the color to work.  First the basics.
>
> This is the xaml for the bubble with a fixed color:
>
> <DataTemplate xmlns='http://schemas.microsoft.com/client/2007'
>  xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
> <Ellipse Stroke="#FF222222" Height="15" Width="15">
> <Ellipse.Fill>
> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
> <GradientStop x:Name="bubbleColor" Offset="0.694"
>                Color="#FF00FF40" />
> <GradientStop Color="#FFE6E6E6"/>
> </LinearGradientBrush>
> </Ellipse.Fill>
> </Ellipse>
> </DataTemplate>
>
> I can add a column based on this template very simply:
>
>         from com_modules.loadxaml import loadXaml
>         from System.Windows.Controls import DataGridTemplateColumn
>         column = DataGridTemplateColumn()
>         column.CellTemplate = loadXaml('templatecolumn')
>         column.Header = 'Bubble'
>
>         grid.Columns.Add(column)
>
> If I try to naively specify a binding in the xaml then I get a 
> PARSER_BAD_PROPERTY_VALUE when I attempt to load the xaml (so no hope 
> of setting up the binding after load):
>
> <GradientStop x:Name="bubbleColor" Offset="0.694" Color="{Binding 
> color}" />
>
>
> One approach I tried was to create a ValueConverter. Here is the 
> skeleton of the class I created:
>
> from System import Type
> from System.Globalization import CultureInfo
> from System.Windows.Data import IValueConverter
>
> class ColorConverter(IValueConverter):
>     _clrnamespace = "Converters"
>     __metaclass__ = clrtype.ClrClass
>
>     @clrtype.accepts(object, Type, object, CultureInfo)
>     @clrtype.returns(object)
>     def Convert(self, value, targetType, parameter, culture):
>         pass
>
>     @clrtype.accepts(object, Type, object, CultureInfo)
>     @clrtype.returns(object)
>     def ConvertBack(self, value, targetType, parameter, culture):
>         pass
>
> As there is a _clrnamespace specified I thought I might then be able 
> to use this converter in xaml. Trying to reference the ColorConverter 
> class in the Converters namespace in a resources dictionary again 
> causes blow ups when loading the xaml.
>
> Setting this up programatically would be ideal. Anyone got any ideas?
>
> All the best,
>
> Michael
>
>
> -- 
> http://www.ironpythoninaction.com/
> http://www.voidspace.org.uk/blog
>   
> READ CAREFULLY. By accepting and reading this email you agree, on behalf of your employer, to release me from all obligations and waivers arising from any and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap, clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and acceptable use policies ("BOGUS AGREEMENTS") that I have entered into with your employer, its partners, licensors, agents and assigns, in perpetuity, without prejudice to my ongoing rights and privileges. You further represent that you have the authority to release me from any BOGUS AGREEMENTS on behalf of your employer.
>   
>
>
>
> -- 
> http://www.ironpythoninaction.com/
> http://www.voidspace.org.uk/blog
>   
> READ CAREFULLY. By accepting and reading this email you agree, on behalf of your employer, to release me from all obligations and waivers arising from any and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap, clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and acceptable use policies ("BOGUS AGREEMENTS") that I have entered into with your employer, its partners, licensors, agents and assigns, in perpetuity, without prejudice to my ongoing rights and privileges. You further represent that you have the authority to release me from any BOGUS AGREEMENTS on behalf of your employer.
>   
>
>
> _______________________________________________
> Users mailing list
> Users at lists.ironpython.com
> http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
>    


-- 
http://www.ironpythoninaction.com/
http://www.voidspace.org.uk/blog

READ CAREFULLY. By accepting and reading this email you agree, on behalf of your employer, to release me from all obligations and waivers arising from any and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap, clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and acceptable use policies ("BOGUS AGREEMENTS") that I have entered into with your employer, its partners, licensors, agents and assigns, in perpetuity, without prejudice to my ongoing rights and privileges. You further represent that you have the authority to release me from any BOGUS AGREEMENTS on behalf of your employer.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/ironpython-users/attachments/20100209/a679ffaf/attachment.html>