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Means of generating an editable form from XML

<press_limits value="1055" label="Press Limits" type="single 317" format="object">
<projected_area value="0.052944637336319995" label="Projected area of part" type="real(m*m)"/>
<press_tonnage value="500.0" label="Press tonnage" type="real(g)" units="0Ton"/>
<within_press_limit value="1" label="within limits of press" type="boolean"/>
From XML like the above, the XAML below will generate a form that displays the values, with appropriate controls and value formats. But I can't get the stuff converted back. I fail to see a simple change that will meet the requirements of Binding. Perhaps fixing this requires an architecture change. How can I do this differently?
The magic starts here. Bind this ItemsControl to an XmlElement, and it builds a ControlChooser for each subelement.
<ItemsControl ItemsSource="{Binding XPath=*}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate><WrapPanel/></ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<W3V:ControlChooser Content="{Binding}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
The ControlChooser triggers on the format attribute:
<Style.Triggers>
<DataTrigger Binding="{Binding XPath=#format}" Value="spin">
<Setter Property="ContentTemplate" Value="{StaticResource combo}" />
</DataTrigger>
to pick a DataTemplate:
<DataTemplate x:Key="combo" > <W3V:ComboView /> </DataTemplate>
which instatiates the following control:
<ComboBox Style="{StaticResource ComboButtonStyle}" Width="200"
Text="{Binding Path=., ## PROBLEM, BUT HOW TO AVOID?
Converter={StaticResource valueFormattingConverter },
IsEditable="True" />
valueFormattingConverter uses the #units, #type, and #value attributes to produce properly formatted text. The trouble is, this doesn't convert back. I asked here: TextBox ConvertBack event doesn't fire for XML element, and learned that it is impossible for Path=. to be used as '.' is an object but not a dependency property.
So then, I need a way to provide a DependencyProperty for Binding. So ComboView needs to receive an object that has a property which is or has the XmlElement I want. I think this means I really need to change things around but haven't the slightest idea how. Maybe there's an MVVM approach to doing this??? Any insights will be appreciated.
An upcoming issue is a need to validate the data typed in and process the information.

The MVVM method: pull the data out of the XML file, and put it a class which is the ViewModel. Each property in the ViewModel corresponds to an item of data in the XML file. Then use a custom DataTemplate to render the contents of the ViewModel to the screen.
We can extend this to render a list of items. Each item in the list is a ViewModel. A DataTemplate always renders based on the type of the property it is attached to. So you can have a list of objects, and a custom DataTemplate for each item in the list. Of course, all of the items in the list would have to inherit from the same type.
This means you can have a list of items, and each item can render differently depending on the type of data in the XML file. This means that each item in the list can have a custom look and feel with different number of decimal places, colors, etc.
I've used this technique before, and it works well.
Update
For examples, see:
http://www.wpftutorial.net/datatemplates.html
http://www.stackoverflow.com/questions/3400532/display-multiple-types-from-a-single-list-in-a-wpf-listbox.

If I was solving this, I would look at generating C# on the fly. Here is how I would do it:
All XAML compiles to a series of C# commands.
I would set the XAML to format things the way I like it.
I would find the equivalent C# code.
I would then insert the appropriate if/else statements to alter the C# to suit.
Another method that I would try:
Its possible to render custom XAML into an area on the screen.
I would edit the XAML, based on the XML, then display this custom XAML on the screen.
I'd be curious to know if either of these methods work in practice, or if there is a better method that would work.

Difference between PATH= and PATH=. on DataBinding

I have just succeeded to use, on c#, the property Binding, I saw two ways to do this:
Binding="{Binding Path=DataBinded}" and Binding="{Binding Path=.DataBinded}"
They are both working, but if there is two ways to write, it's for a reason...What's the difference between Path= and Path=. ?

usually . refers to the preceding object and allow you to point to the sub properties, you may consider it as a separator as well. as mentioned in the question there is no preceding object so in this case the . refers to the DataContext itself and so Binding="{Binding Path=DataBinded}" and Binding="{Binding Path=.DataBinded}" are equal
you may consider the following example when you want to bind some text value directly
<TextBlock Text="{Binding}" />
or
<TextBlock Text="{Binding Path=.}" />
both of the example above points to the DataContext of the TextBlock and will bind to the same.

Using a period path ("Path=.") will bind to the current source :)
You can read the docs here under remarks seccion (last point)

Passing DataGridRow as Object to a Converter

Once again I have a little problem with WPF, XAML and probably my own stupidity ;)
I have a DataGrid which is bound to the DataContext. The DataContext is an array of Objects from a Class I made myself (something simple like class Employee with Properties like FirstName, LastName, etc... really nothing special.)
I wanted to create a ToolTip for the rows, so I made a RowStyle where I assigned the ToolTip. It was first bound to a Property named 'Status'. The following code worked fine:
<DataGrid.RowStyle>
<Style TargetType="DataGridRow">
<Setter Property="ToolTip">
<Setter.Value>
<TextBlock Text="{Binding Status Converter={StaticResource StatusToolTipConverter}}"/>
</Setter.Value>
</Setter>
</Style>
</DataGrid.RowStyle>
But then I changed my mind. I don't want to pass only the "Status" Property, now I want to pass the whole Object (Remember: one row = one object). Or in other words: I want to Pass the DataContext of the row to my converter. Since the Object that I want to pass is the DataContext itself, there shouldn't be much to change. So I changed it to:
<TextBlock Text="{Binding Converter={StaticResource StatusToolTipConverter}}"/>
Now here is where things start to go wrong. The converter gets 'null' as value. So I deleted the converter and tried it again. The ToolTip was correctly bound to the Object in the Row. I could proof that to myself because the correct Object name was shown in the tooltip. I even overwrote the .ToString() so that the Name of the Employee gets shown as Object name, which it did correctly without the converter.
so TL;DR: Why does the Converter get 'null' as Value, when the Object is bound correctly WITHOUT the converter?

I found a little workaround. I made a property called 'Self' which returns 'this'. The ToolTip is now bound to 'Self'. It works.

How to set focus to textbox using MVVM?

How to focus a textbox from ViewModel wpf?
<TextBox Name="PropertySearch"
Text="{Binding UpdateSourceTrigger=PropertyChanged,
Mode=TwoWay, Path=PropertySearch,
ValidatesOnDataErrors=True}"
Width="110"
Height="25"
Margin="10" />

You can do this by adding a property to your ViewModel (or use an existing property) that indicates when the SetFocus should happen but the View should be responsible for actually setting the focus since that is purely View related.
You can do this with a DataTrigger.
View:
<Grid Name="LayoutRoot" DataContext="{StaticResource MyViewModelInstance}">
<Grid.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding UserShouldEditValueNow}" Value="True">
<Setter Property="FocusManager.FocusedElement" Value="{Binding ElementName=PropertySearch}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Style>
<TextBox Name="PropertySearch" Text="{Binding UpdateSourceTrigger=PropertyChanged, Mode=TwoWay, Path=PropertySearch, ValidatesOnDataErrors=True}" Width="110" Height="25" Margin="10" />
</Grid>
ViewModel:
// When you think the view should set focus on a control
this.UserShouldEditValueNow = true;
The example above is simplified by just using a boolean ViewModel property "UserShouldEditValueNow". You can add a property like this to your ViewModel or use some other exising property that indicates this state.
Note: So why is it done this way in MVVM? One reason is, suppose the View author decided to replace the TextBox with a ComboBox, or even better, suppose your property was an integer value that had both a TextBox to view/edit the number and a Slider as another way to edit the same value, both controls bound to the same property... how would the ViewModel know which control to set focus on? (when it shouldn't even know what control, or controls, are bound to it in the first place) This way the View can select which control to focus by changing the ElementName binding target in the DataTrigger Setter.
Happy coding!

The question you should be asking yourself is "why does my ViewModel need to know which control has the focus?"
I'd argue for focus being a view-only property; it's an interaction property, and has nothing to do with the conceptual state. This is akin to the background color of a control: why would you represent it in the VM? If you need to manage the focus in a custom way, it's probably better to use a view-level object to do the job.

In your parent control, add the following property:
FocusManager.FocusedElement="{Binding ElementName=PropertySearch}"

While purists may argue for leaving this out of the VM, there are cases where it may make sense to do so from the VM.
My approach has been to make the view implement an interface, pass that interface to the ViewModel, and then let the VM call methods on the interface.
Example:
public interface IFocusContainer
{
void SetFocus(string target);
}
A couple things to keep in mind:
A VM might serve more than one instance of a view, so your VM might want to have a collection of references to IFocusContainer instances, not just one.
Code the VM defensively. You don't know whether there are 0, 1 or 20 views listening.
The "target" parameter of SetFocus() should probably be "loosely" coupled to the VM. You don't want the VM caring about the exact control names in the UI. Rather, the VM should indicate a name that is defined solely for focus management. In my case, I created some attached properties that would allow me to "tag" controls with "focus names".
To implement the interface, you can:
Implement it in the code-behind
Create some behaviors that know how to attach to the ViewModel that is present in the DataContext.
There's nothing wrong with implementing it on the Code Behind, but the behavior approach does allow a XAML only hookup if that's important to you.
In the implementation of the interface, you can use the visual tree to locate the control, or you could just code up a switch statement for a known set of focusable items.

WPF ContextMenu bind some property to another property of the same control

I have a ContextMenu and a ColumnHeaderStyle defined in Window.Resource section which I use-it to a DataGrid ColumnHeader. My code is something like this:
<ContextMenu x:Key="cm_columnHeaderMenu"/>
<Style x:Key="DefaultColumnHeaderStyle" TargetType="{x:Type DataGridColumnHeader}">
<Setter Property="ContextMenu" Value="{StaticResource cm_columnHeaderMenu}" />
</Style>
<DataGrid Grid.Column="2" Grid.Row="1" x:Name="dgridFiles" IsReadOnly="True"
ColumnHeaderStyle="{StaticResource DefaultColumnHeaderStyle}">
I want to know if I can (and if the answer it true, then HOW I can I do it) bind the ContextMenu Visibility property to same control ContextMenu Items.Count > 0 property.
Initially based on some other treeView control selections made there shoud be no items in the context menu, but i wish to add dinamically items in ContextMenu based on selection in treeView. This part is done, the context has those items. On some selections there are no-items, but still on the grid it appears an empty ContextMenu. So I believe the easiest part it would be to bind the Visibility to Items.Count property of the same control.
Sorry if my english is not good enough, I'll try to explain better if i didnt make clear 1st time.

you want to bind via RelativeSource, especially the Self mode.
I think by reading this or this you will be able to achieve your goal.
Then you'll need a binding converter to convert the integer values to the matching type and values of the Visibility property. You'll find a short tutorial here.
Regards

Using this you can bind to the property in the same control
Visibility="{Binding Path=Items.Count, RelativeSource={RelativeSource Self}}"
You also have to use a converter to achieve what you want.
Just in case you need this

Try a converter to convert the value of the item count to a boolean. So you'll end up with something like
<ContextMenu Visibility={Binding RelativeSource={RelativeSource Self},
Converter={StaticResource ItemsToVisibilityConverter}, Path=Items.Count}} />
If that doesn't work, try this with data triggers (you still need a converter anyway, and this shows a converter at work):
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/a8ad8c14-95aa-4ed4-b806-d0ae874a8d26/