C# find a specific element with two or more xml files?

Question

I try to explain my problem:

Okay, I need the KSCHL and the Info. I need the KSCHL from the result file and then I want to search after the KSCHL in the other file "Data".

In the first file I have all KSCHL.

var kschlResultList = docResult.SelectNodes(...);
var kschlDataList = docData.SelectNodes(...);
var infoDataList = docData.SelectNodes(...);

for (int i = 0; i < kschlResultList.Count; i++)
{
    string kschlResult = kschlResultList[i].InnerText;

    for (int x = 0; x < kschlDataList.Count; x++)
    {
        string kschlData = kschlDataList[x].InnerText;

        if (kschlData == kschlResult)
        {
            for (int y = 0; y < infoDataList.Count; y++)
            {
                string infoData = infoDataList[y].InnerText;

                if (infoData == kschlResult)
                {   
                    //I know the If is false 
                    string infoFromKschl = infoData;
                }
            }
        }
    }
}

The problem is now to find the KSCHL (from the first file) in the second file and then to search after the "info".

So if I have the KSCHL "KVZ1" in the first file, then I want to search this KSCHL in the second file and the associated Info for it.

Hope you understand :)

Answer 1

You don't have to loop quite so much. :-)

Using XPath - the special strings inside SelectNodes() or SelectSingleNode(), you can go pretty directly to what you want.

You can see a great basic example - several really - of how to select an XML node based on another node at the same level here:
How to select a node using XPath if sibling node has a specific value?

In your case, we can get to a list of the INFO values more simply by looping just through the KSCHL values. I use them as text, because I want to make a new XPath string with them.

I'm not clear exactly what format you want the results in, so I'm simply pushing them into a SortedDictionary for now.

At that last step, you could do other things as is most useful to you..... such as push them into a database, dump them in a file, send them to another function.

    /***************************************************************
     *I'm not sure how you want to use the results still, 
     *  so I'll just stick them in a Dictionary for this example.
     *  ***********************************************************/
    SortedDictionary<string, string> objLookupResults = new SortedDictionary<string, string>();

    // --- note how I added  /text()... doesn't change much, but being specific  <<<<<<
    var kschlResultList = docresult.SelectNodes("//root/CalculationLogCompact/CalculationLogRowCompact/KSCHL/text()");

    foreach (System.Xml.XmlText objNextTextNode in kschlResultList) {

        // get the actual text from the XML text node
        string strNextKSCHL = objNextTextNode.InnerText;

        // use it to make the XPath to get the INFO  ---  see the [KSCHL/text()= ...
        string strNextXPath = "//SNW5_Pricing_JKV-Q10_full/PricingProcedure[KSCHL/text()=\"" + strNextKSCHL + "\" and PRICE>0]/INFO/text()";

        // and get that INFO text!  I use SelectSingleNode here, assuming only one INFO for each KSCHL.....  if there can be more than one INFO for each KSCHL, then we'd need another loop here
        string strNextINFO = docdata.SelectSingleNode(strNextXPath)?.InnerText;  // <<< note I added the ? because now there may be no result with the rule PRICE>0.


        // --- then you need to put this result somewhere useful to you.
        //      I'm not sure what that is, so I'll stick it in the Dictionary object.  
        if (strNextINFO != null) {
            objLookupResults.Add(strNextKSCHL, strNextINFO);
        }

    }