<tab name="Xamarin">
<source lang = "xml">
<controls:EvalExpression x:Key="EvaluatorFilterExpression" Expression="(P1==null||P1=="")?"true":P0" Context="{Binding}">
<controls:EvalExpressionParameter Name="P0" Value="{Binding Path=Text, Source={x:Reference Filter_Input}, Converter={StaticResource Formatter}, ConverterParameter='Item.Values["NAME"].ToLower().Contains("{0}".ToLower())==true'}" />
<controls:EvalExpressionParameter Name="P1" Value="{Binding Path=Text, Source={x:Reference Filter_Input}}" />