Question

How do I check to see if an element exists within a given element before trying to add it?

Background: I have an XDocument X that contains as a child element Flowers which subsequently contains a series of elements that are each named Flower. Each Flower already has 2 child elements and I would like to add a 3rd element called Price. However, I want to check and make sure there’s not already an element for Price within the Flower element. How do I do that? Do I even need to check?

Answer 1

XElement has a HasElements property, which would work if just wanted to know whether any elements existed or not.

For your case, I would use…

XNamespace ns = "http://mynamespace.com";
bool hasPrice = flowerElement.Element(ns + "Price") == null;

..to see if a the price element exists. If not, you can then add it.

Note: if you don’t have any namespace set for your XML file, you can use Namespace.None instead of ns.