Question

I have an XmlElement with several attributes

xeObject = <Object Name="Object1" Site="Site1" ... />

I also have a list of XmlElements with several (possibly different) attributes

l_xeObject = <Object ... /><Object ... /> ... <Object ... />

I would like a function call like

FindMatchingElements(xeObject, l_xeObject, "Name", "Site")

where any elements in l_xeObject that have the same values as xeObject.Name and xeObject.Site are returned!

Can i do this with Linq?

… I already have the following function

public static List<XmlElement> GetXmlElementsFromListWithMatchingAttribute
    (XmlElement xeMatchOn, string sMatchingAttributeName, List<XmlElement> l_xeSearchIn)
{
    return (l_xeSearchIn
        .Where(xe => xe.Attributes[sMatchingAttributeName].Value
            == xeMatchOn.Attributes[sMatchingAttributeName].Value)
        ).ToList();
}

but it only uses one attribute.

Thanks to Frédéric for the answer i needed.

Answer 1

You can use All() to match several attributes and GetAttribute() to avoid having to check for null:

public static IEnumerable<XmlElement> FindMatchingElements(XmlElement match,
    IEnumerable<XmlElement> elements, params string[] attributeNames)
{
    // Argument validation omitted for brevity.

    return elements.Where(
        element => attributeNames.All(
            name => element.GetAttribute(name) == match.GetAttribute(name)));
}

That said, if you really want to parse or generate XML markup with LINQ, consider using LINQ to XML instead of the DOM classes.