Advanced Binding (first to xml then to something else)

Question

first of all sorry for the title. I know this is not so clear but i cannot think of anything else. If someone wants me to change it, give your suggestions please (and please note that downvoting is not the right solution here) thanks. Now my problem. I have an xml that look like this:

<scenarios-list>


<scenario name="Fuori casa" value="fuori-casa">
    <lights>
        <lights-group name="soggiorno">
          <lights-item name="portone" outputChannelName="Luci|Appartamento|Portone|DO_Stato" inputChannelName="Luci|Appartamento|Portone|DI_On_Off">off</lights-item>
          <lights-item name="soggiorno-principale" outputChannelName="Luci|Appartamento|Soggiorno_Principale|DO_Stato" inputChannelName="Luci|Appartamento|Soggiorno_Principale|DI_On_Off">off</lights-item>
          <lights-item name="soggiorno-secondario" outputChannelName="Luci|Appartamento|Soggiorno_Secondario|DO_Stato" inputChannelName="Luci|Appartamento|Soggiorno_Secondario|DI_On_Off">off</lights-item>
          <lights-item name="parete-zona-cucina" outputChannelName="Luci|Appartamento|Parete_Zona_Cucina|DO_Stato" inputChannelName="Luci|Appartamento|Parete_Zona_Cucina|DI_On_Off">off</lights-item>
          <lights-item name="finestra-soggiorno" outputChannelName="Luci|Appartamento|Finestra_Soggiorno|DO_Stato" inputChannelName="Luci|Appartamento|Finestra_Soggiorno|DI_On_Off">off</lights-item>
        </lights-group>

        ... (lots of <lights-group> here)

    </lights>

    ... (lots of <lights> here)

</scenario>

...(lots of <scenario> here)

</scenarios-list>

I have a usercontrol in which the user can see and edit this scenarios:

<Grid Name="BaseGrid">

        <Grid.Resources>
            <XmlDataProvider **x:Name="ScenesXmlName"** x:Key="ScenesXml" XPath="scenari-list/scenario" Source="C:\Users\andrea\RSSReaderSubscriptions-5.xml"/>
        </Grid.Resources>

        <ComboBox Name="ScenariCombo"
                  **ItemsSource="{Binding Source={StaticResource ScenesXml}}" DisplayMemberPath="@name"**/>


        <StackPanel>
                <ListBox Name="LightsList" **ItemsSource="{Binding Source={StaticResource ScenesXml}, XPath=lights/lights-group}**">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Expander Name="LightsExpander" **Header="{Binding XPath=@name}"** >
                                <ListBox>
                                    <ListBox.ItemTemplate>
                                        <DataTemplate>
                                            <StackPanel Orientation="Horizontal">
                                                <Label **Content="{Binding XPath=ligths-item@name}"** />
                                                <CheckBox />
                                            </StackPanel>
                                        </DataTemplate>
                                    </ListBox.ItemTemplate>
                                </ListBox>
                            </Expander>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </StackPanel>
    </Grid>

So basically i want to:

• load the <scenarios-list> into the combobox (displaying just the scenario's name) [My code already does this]
• load the <lights-group> list into the listbox basing on the selected combobox item (display only the name of the lights-group) [My code already does this even if i get this error:

System.Windows.Data Error: 43 : BindingExpression with XPath cannot bind to non-XML object.; XPath='lights/lights-group' BindingExpression:Path=; DataItem='XmlDataCollection' (HashCode=56809051); target element is 'ListBox' (Name='LightsList'); target property is 'ItemsSource' (type 'IEnumerable') XmlDataCollection:'MS.Internal.Data.XmlDataCollection'

• inside every Expander load all <lights-item> that are included into the <lights-group> [I don't have the faintest idea on how to do this]

Can you help me please?

Answer 1

I managed to get i tworking with this code:

<Grid Name="BaseGrid">

    <Grid.Resources>
        <XmlDataProvider x:Name="ScenesXmlName" x:Key="ScenesXml" XPath="scenari-list/scenario" Source="myPath"/>
    </Grid.Resources>

    <ComboBox Grid.Column="0" Grid.Row="1" Name="ScenariCombo" IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding Source={StaticResource ScenesXml}}" DisplayMemberPath="@name"/>


<StackPanel>
<ListBox Name="LightsList" ItemsSource="{Binding Source={StaticResource ScenesXml}, XPath=lights/lights-group}">
                        <ListBox.ItemTemplate>
                            <DataTemplate>
                                <Expander Header="{Binding XPath=@name}" HorizontalAlignment="Stretch">
                                    <ListBox IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding XPath=lights-item}">
                                        <ListBox.ItemTemplate>
                                            <DataTemplate>
                                                <Grid>
                                                    <Grid.ColumnDefinitions>
                                                        <ColumnDefinition Width="*" />
                                                        <ColumnDefinition Width="150" />
                                                    </Grid.ColumnDefinitions>
                                                    <Label Content="{Binding XPath=@name}" Grid.Column="0"/>
                                                    <CheckBox Grid.Column="1" IsChecked="{Binding XPath=., Converter={StaticResource myStateToBoolConverter}}"/>
                                                </Grid>
                                            </DataTemplate>
                                        </ListBox.ItemTemplate>
                                    </ListBox>
                                </Expander>
                            </DataTemplate>
                        </ListBox.ItemTemplate>
                    </ListBox>
    </StackPanel>


</Grid>

So the key seems to be IsSynchronized="true". Hope this is useful for other people.