The IListFeed<T> is feed specialized for handling collections. It allows the declaration of an operator directly on items instead of dealing with the list itself. A list feed goes in None if the list does not have any elements.


ListFeed<T> is using the key equality to track multiple version of a same entity whitin different messages of the ListFeed<T>. (Read more about key equality.)[../KeyEquality/]

Sources: How to create a list feed

To create an IListFeed<T>, on the ListFeed class, the same Async, AsyncEnumerable and Create methods found on Feed can be used.

There are also 2 helpers that allow you to convert from/to a feed to/from a list feed.


This allows the creation of a feed of a paginated list. The pagination can be made by cursor (cf. ListFeed<T>.AsyncPaginatedByCursor), or using a simple page index with ListFeed.AsyncPaginated. Used among the generated view models and a ListView, when the user scroll and reach the end of the list, a PageRequest will be sent to the ListFeed, which will trigger the load of the next page using the delegate that you provided.

public IListFeed<City> Cities => ListFeed.AsyncPaginated(async (page, ct) => _service.GetCities(pageIndex: page.Index, perPage: 20));


On the Page struct you have a DesiredSize property. This is the number of items the view is requesting to properly fill its "viewport", BUT there is no garantee that this value remains the same between multi pages, espcially if the user resize the app. As a consequency, it must not be used with Index for a "skip/take" pattern like source.Skip(page.Index * page.DesiredSize).Take(page.DesiredSize). For such patterns, you can either just hard-code your page size (e.g. source.Skip(page.Index * 20).Take(20), either use the page.TotalCount property (e.g. source.Skip(page.TotalCount).Take(page.DesiredSize)).


This allows the creation of a list feed from a feed of list.

public IListFeed<WeatherInfo> Forecast => Feed
	.Async(async ct => new []
		await _weatherService.GetWeatherForecast(DateTime.Today.AddDays(1), ct),
		await _weatherService.GetWeatherForecast(DateTime.Today.AddDays(2), ct),
	.Select(list => list.ToImmutableList())


This does the opposite of AsListFeed and converts a list feed to a feed of list.

public IFeed<IImmutableList<WeatherInfo>> ForecastFeed => Forecast.AsFeed();

Operators: How to interact with a list feed

Unlike a Feed<List<T>> operators on a list feed are directly interacting with items instead of the list itself.


This operator allows the filtering of items.


If all items of the collection are filtered out, the resulting feed will go in none state.

public IListFeed<WeatherInfo> HighTempDays => ForecastFeed.Where(weather => weather.Temperature >= 28);