public static XmlElement SelectOrAppendElement(this XmlNode parentNode, XPathLocationStep locationStep)
{
Arguments.Validation.Constraints
.IsNotNull(parentNode, nameof(parentNode))
.Check();
return((XmlElement)parentNode.SelectSingleNode(locationStep.Value) ?? parentNode.AppendElement(locationStep));
}
private static XmlElement AppendElement(this XmlNode parentNode, XPathLocationStep locationStep)
{
if (!locationStep.IsValid)
{
throw new InvalidOperationException($"The XPath location step '{locationStep.Value}' is not valid.");
}
var element = (parentNode.OwnerDocument ?? (XmlDocument)parentNode).CreateElement(locationStep.ElementName);
parentNode.AppendChild(element);
if (locationStep.AttributeSpecifications.Any())
{
foreach (var attributeSpecification in locationStep.AttributeSpecifications)
{
attributeSpecification.Execute(element);
}
element.AppendAttribute(
XmlAttributeNames.DISCRIMINANT,
Constants.NAMESPACE_URI,
Constants.NAMESPACE_URI_PREFIX,
string.Join(Constants.DISCRIMINANT_SEPARATOR.ToString(), locationStep.AttributeSpecifications.Select(specification => specification.Name)));
}
return(element);
}
