If its part of DataTemple how to handle?

I have TileManager having ItemeTemplate InfragisticChart which has variable ScatterSeries.I have used the code.I get error 

 SeriesType type = (SeriesType)seriesSource.GetType().GetProperty(TypePath).GetValue(seriesSource, null);

TypePath null exception.

<ig:XamTileManager
TileCloseAction="RemoveItem"
Grid.Row="0"
Name="XamTileManager1"
Margin="10,0,0,0" HeaderPath="Name" ItemsSource="{Binding Spectrums}"
>

<ig:XamTileManager.NormalModeSettings>
<ig:NormalModeSettings AllowTileDragging="Swap"
AllowTileSizing="Individual"
HorizontalTileAreaAlignment="Stretch"
ShowAllTiles="True"
TileLayoutOrder="UseExplicitRowColumnOnTile"
VerticalTileAreaAlignment="Stretch" />
</ig:XamTileManager.NormalModeSettings>
<ig:XamTileManager.MaximizedModeSettings>

<ig:MaximizedModeSettings AllowTileDragging="Slide"
HorizontalTileAreaAlignment="Stretch"
MaximizedTileLocation="Left"
MinimizedTileExpandButtonVisibility="Visible"
MinimizedTileExpansionMode="AllowOne"
ShowAllMinimizedTiles="True"
ShowTileAreaSplitter="True"
VerticalTileAreaAlignment="Stretch" >
</ig:MaximizedModeSettings>
</ig:XamTileManager.MaximizedModeSettings>

<!--Start of the normal item template-->
<ig:XamTileManager.ItemTemplate>
<DataTemplate>
<ig:XamDataChart x:Name="MainPlot"
Background="White"
PlotAreaMargin="5"
DefaultAxisStroke="Black"
DefaultInteraction="DragZoom"
FontWeight="Normal"
Foreground="Black"
HorizontalZoomable="True"
TitleHorizontalAlignment="Center"
VerticalZoomable="True">
<local:SeriesBinderBehavior.SeriesBinder>
<local:SeriesBinderInfo
ItemsSourcePath="Source"
XMemberPath="XPath"
YMemberPath="YPath"
TypePath="Type"
SeriesSource="{Binding SeriesSource}"/>
</local:SeriesBinderBehavior.SeriesBinder>
</ig:XamDataChart>
</DataTemplate>
</ig:XamTileManager.ItemTemplate>
<!--End of the maximized template-->
</ig:XamTileManager>

Thanks Stefan its solved my problem.

Hello Stefan,

Thanks for support, I know very well how to handle events in MVVM, I was solved the legend title issue through LegendItemTemplate, and its look good i need only tooltip of every auto generated series, i didn't find any solution of auto generated series tooltip I was attached the modified sample with snapshot (red circled tooltip)  in sample project folder, can you modified my attached sample with tooltip that i was shown in snapshot ? modified sample is really very helpful for me.