ItemsRepeater to search DataTemplates when no ItemTemplate defined

The ItemsRepeater is inconsistent with the other Avalonia controls in that it doesn’t appear to search the DataTemplates collections of its parent controls for a matching DataTemplate for it’s items. Instead it reverts to using ToString() when no ItemTemplate is defined; e.g. <ItemsRepeater Items="{Binding Items}"/>

The similar ItemsControl works as expected using the DataTemplates of its parent controls. <ItemsControl Items="{Binding Items}"/>

I think it would make sense for ItemsRepeater to default to searching the Avalonia DataTemplates collections for a matching template.

[maxkatz6]

@nrenzoni you need to use recycle pool for items repeater https://github.com/AvaloniaUI/Avalonia/blob/master/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml#L25-L43

[nrenzoni]

This is the behavior from the upstream ItemsRepeater and I’d be hesitant to diverge from the behavior there for a few reasons:

• It would make future porting of features/fixes from upstream more difficult
• It would disable element recycling, because we we need to wrap the ItemTemplate in an ElementFactory in order to implement recycling. If we have to search DataTemplates then there can be a different data template for each element

If you want your ItemsRepeater to search DataTemplates then the simplest way is to put a ContentPresenter or ContentControl-derived control in the ItemsRepeater.ItemTemplate property, Note that you may see decreased performance however because only the ContentPresenter can be recycled in this case, and not the content itself.

I’m going to close this issue as by design but please feel free to continue discussion.

Can you share code for how to do this? I have the use case where my ItemsRepeater.Items is a collection of an abstract class type, and I’d like to have different DataTemplates per each concrete class type. I thought I could define the Data Templates in ItemsRepeater.DataTemplates, but it’s not being referenced, similar to this github issue.