C# Shorthand LINQ .Where statement

Question

Just a little confused how to achieve this.

I have categories generated by the site and by the user and I want to return items where the associated user generated category if there is one is active. So I have this which works fine if a category is selected but if the category is null it obviously fails as theres no object to get the isActive property.

var item = User.Items.Where(x => x.Categoires.FirstOrDefault(s => !s.isSystem).isActive)

So I just need a check if the first or default is null, any help would be much appreciated.

Thanks

Answer 1

Perhaps:

var item = User.Items
   .Where(ui => ui.Categoires.Any(uic => !uic.isSystem && uic.isActive));

This returns user-items with at least one active non-system-category.

A category is an optional field on item, and a category has a state of isActive, so if the item has an associated category which it doesnt have to, then that category must be active.

Then you have to include items without a category (i assume it cannot be null):

var item = User.Items
   .Where(ui => !ui.Categoires.Any() || ui.Categoires.Any(uic => !uic.isSystem && uic.isActive));