4.15 AutoExpand attribute

In OData WebApi 5.7, we can put AutoExpand attribute on navigation property to make it automatically expand without expand query option, or can put this attribute on class to make all Navigation Property on this class automatically expand.

Model

public class Product
{
    public int Id { get; set; }
    [AutoExpand]
    public Category Category { get; set; }
}

public class Category
{
    public int Id { get; set; }
    [AutoExpand]
    public Customer Customer{ get; set; }
}

Result

If you call return Product in response, Category will automatically expand and Customer will expand too. It works the same if you put [AutoExpand]on Class if you have more navigation properties to expand.