Question

In many Umbraco examples i see two different approaches for the same types of work. Sometimes people select, query and return INode. Other people do everything with Node.

Can anyone tell me which is the preferred way of working?

Answer 1

I’m not familiar with Umbraco, but I don’t think that the answer has to be specific to it.

If you return INode, it gives you flexibility in the future in that you can return (internally) any class that extends from INode. if INode contains all properties and methods of Node, then no functionality is lost from doing this.

Take for example, the opportunity of using IEnumerable vs List

IEnumerable<int> x = MyClass.MyMethod();

Both the following definitions of MyMethod would be valid in this class example.

public static IEnumerable<int> MyMethod()
{
    return new List<int>() { 1, 2, 3 };
}

....

public static IEnumerable<int> MyMethod()
{
    return new int[] {1, 2, 3};
}

This lets you change the implementation of MyMethod without having to modify each caller.

For your methods, you should return the simplest type that gives all the functionality relavant to its context. Say if you need to modify the list that MyMethod returns, then returning IEnumerable is a bad choice (as it’s immutable).