Querying CIM XML in C# with LINQ

Question

I am looking for a way to query CIM XML files with LINQ, in order to speed up my analysis of data and verify the exports from a database containing the elements of electrical network. Since I am a newbie in C#, I guessed that it will be easy to load the CIM XML in console application and based on tag values filter some elements. However, all tutorials that I found so far are straight-forward where elements are named like "Student", "Purchase", etc.

My elements are named like "cim:LoadBreakSwitch", where "cim" is actual address defined in root node.

This way, when I try to select all elements named like "cim:LoadBreakSwitch", I get an exception thrown on Run Time because the name of a element cannot contain colon.

Example of element that I want to select from the CIM XML file:

<cim:LoadBreak rdf:ID="101">
    <cim:ConductingEquipment.phases>A</cim:ConductingEquipment.phases>
    <cim:IdentifiedObject.description>PoleMounted</cim:IdentifiedObject.description>
 </cim:LoadBreak>

When I print in the console the names of all elements with

IEnumerable<XElement> elements = xmlDoc.Elements();

        foreach (var item in elements)
        {
            Console.WriteLine(item.Name);
        }

I get something like "{http://[address from the root node]}LoadBreak".

I don't know if there is possibility to do it, but I am just curious did anyone who is experienced developer had need to do something similar.

`cim` and `rdf` are namespace prefixes. [Here is an example of working with namespaces](https://stackoverflow.com/questions/16018434/query-xdocument-with-xmlns-attribute-namespace) — Crowcoder, Mar 21 '21 at 11:49
Using XElement : doc.Descendants().Where(x => x.Name.LocalName == "LoadBreak").ToList(); — jdweng, Mar 21 '21 at 12:37
@jdweng that xml may be using namespaces for a reason. That will return unwanted results if element names are used in different namespaces. — Crowcoder, Mar 21 '21 at 12:39
Thans, @Crowcoder. I will take a look in the article you provided. I was not aware of namespace, even the term, to be honest. You have opened new subject for me to investigate. — Davor Cacic, Mar 21 '21 at 13:50
@jdweng agreed, but I would not suggest it without seeing a full schema of the xml. If there were collisions it could easily go unnoticed at runtime. — Crowcoder, Mar 21 '21 at 14:03
Also, thank you, @jdweng. What I was actually looking for is better understanding of the subject. However, I really appreciate code your provided and it will give me another perspective. — Davor Cacic, Mar 21 '21 at 14:03

score 0 · Accepted Answer · answered Mar 21 '21 at 15:39

Your XML is missing a root element with namespace declarations.

Here is a conceptual example for you. It shows how to handle namespaces and query XML with them.

c#

void Main()
{
    XDocument xdoc = XDocument.Parse(@"<rdf:RDF xmlns:cim='http://iec.ch/TC57/2008/CIM-schema-cim13#'
                 xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
            <cim:LoadBreak rdf:ID='101'>
                <cim:ConductingEquipment.phases>A</cim:ConductingEquipment.phases>
                <cim:IdentifiedObject.description>PoleMounted</cim:IdentifiedObject.description>
            </cim:LoadBreak>
        </rdf:RDF>");

    XNamespace cim = xdoc.Root.GetNamespaceOfPrefix("cim");
    XNamespace rdf = xdoc.Root.GetNamespaceOfPrefix("rdf");

    foreach (XElement xelem in xdoc.Descendants(cim + "LoadBreak").Elements())
    {
        Console.WriteLine("{0}: {1}"
            , xelem.Name.LocalName
            , xelem.Value);
    } 
}

Output

ConductingEquipment.phases: A
IdentifiedObject.description: PoleMounted

Thank you for you example and clarification. It helps a lot! — Davor Cacic, Mar 21 '21 at 19:02

Querying CIM XML in C# with LINQ

1 Answers1