Selecting Items from a List
Problem
Selecting items from dynamic lists can be tricky, especially when using paginated data. Doing it manually often adds extra code and makes things more complicated.
Solution
Uno.Extensions.MVUX makes item selection easier by offering a built-in Selection method. This lets you manage the selected items with less code and better structure.
Using Selection
As an example, in Chefs, it is possible to create and edit Cookbooks that are a list of recipes. On the Favorites page, under the My Cookbooks tab, there is a list of existing Cookbooks, and the recipes associated with the Cookbook are represented by the Recipes ListFeed:
public IListFeed<Recipe> Recipes => ListFeed
.PaginatedAsync(
async (PageRequest pageRequest, CancellationToken ct) =>
await _recipeService.GetFavoritedWithPagination(pageRequest.DesiredSize ?? DefaultPageSize, pageRequest.CurrentCount, ct)
)
.Selection(SelectedRecipes);
When creating or editing a Cookbook, we need to have access to the selected recipes that will be linked to the Cookbook. In order to dynamically access it, we use the .Selection() method to link the selected recipes to the SelectedRecipes property. Now, when saving the changes, we can dynamically access the selected recipes:
public async ValueTask Submit(CancellationToken ct)
{
var selectedRecipes = await SelectedRecipes;
var cookbook = await Cookbook;
if (selectedRecipes is { Count: > 0 } && cookbook is not null && cookbook.Name.HasValueTrimmed())
{
var response = IsCreate
? await _cookbookService.Create(cookbook.Name!, selectedRecipes.ToImmutableList(), ct)
: await _cookbookService.Update(cookbook, selectedRecipes, ct);
if (IsCreate)
{
await _cookbookService.Save(response!, ct);
}
await _navigator.NavigateBackAsync(this);
}
else
{
await _navigator.ShowDialog(this, new DialogInfo("Error", "Please write a cookbook name and select one recipe."), ct);
}
}