Property Based Content Filters

A collection of property-based content filtering criteria can be applied to child object lists. Some common use cases are as follows.

• A user can enter a text to reduce the entire child list to a sub list of those whose certain property display values contain that text;
• A customizer can create UI that presents several text input fields serving as such filters, with each applied to a different property.

For example. One can customize the ChildArea template to include the following.

    <Grid>
      <Border Background="#8000488E" Visibility="{Binding Children.Filters[SomePropertyName], Converter={StaticResource NullObjOrEmptyStrColConverter}}" />
      <Border Background="#90707070" Visibility="{Binding Children.Filters[SomePropertyName], Converter={StaticResource NullObjOrEmptyStrVisConverter}}" />
      <TextBox Text="{Binding Children.Filters[SomePropertyName], Mode=TwoWay, Converter={StaticResource FilterCriterionToValueConverter}}"
               PlaceholderText="SomePropertyName" BorderThickness="0" Foreground="White" Background="Transparent" />
    </Grid>

This is shown as a single text box. The two way binding on Text allows the entered text (case insensitive) to be used as the filter value on property "SomePropertyName" (case sensitive).

For performance/usability reasons, the result list is not immediately refreshed as one types in the text box. Instead, it only happens after the ReloadChildListCommand is triggered.

The Borders in the example are not mandatory. They serve as indicators of whether a filter is currently applied on the result list. The PlaceHolderText is optional as well.