How to retrieve XML nodes with specific content?

Question

I am building a service who receive xml payload and after treating my internal request respond a new xml response to the caller

Now to facilitate the work i created a XML template where i have put all my template in xml files.

below is the content of my xml template.

<?xml version="1.0" encoding="utf-8" ?>
<FPEnvelope xmlns="namespace1"
xmlns:document="namespace2"
xmlns:header="namespace3">
  <header:AppHdr>
    <header:Fr>
      <header:FIId>
        <header:FinInstnId>
          <header:Othr>
            <header:Id>{{SWITCH}}</header:Id>
          </header:Othr>
        </header:FinInstnId>
      </header:FIId>
    </header:Fr>
    <header:To>
      <header:FIId>
        <header:FinInstnId>
          <header:Othr>
            <header:Id>{{BIC2}}</header:Id>
          </header:Othr>
        </header:FinInstnId>
      </header:FIId>
    </header:To>
    <header:BizMsgIdr>{{BizMsgIdr}}</header:BizMsgIdr>
    <header:MsgDefIdr>pacs.002.001.12</header:MsgDefIdr>
    <header:CreDt>{{CreDt}}</header:CreDt>
    <header:Rltd>
      <header:Fr>
        <header:FIId>
          <header:FinInstnId>
            <header:Othr>
              <header:Id>{{BIC2}}</header:Id>
            </header:Othr>
          </header:FinInstnId>
        </header:FIId>
      </header:Fr>
      <header:To>
        <header:FIId>
          <header:FinInstnId>
            <header:Othr>
              <header:Id>{{SWITCH}}</header:Id>
            </header:Othr>
          </header:FinInstnId>
        </header:FIId>
      </header:To>
      <header:BizMsgIdr>{{BizMsgIdr}}</header:BizMsgIdr>
      <header:MsgDefIdr>pacs.002.001.12</header:MsgDefIdr>
      <header:CreDt>{{CreDt}}</header:CreDt>
    </header:Rltd>
  </header:AppHdr>
  <document:Document>
    <document:FIToFIPmtStsRpt>
      <document:GrpHdr>
        <document:MsgId>{{MsgId}}</document:MsgId>
        <document:CreDtTm>{{CreDtTm}}</document:CreDtTm>
        <document:InstgAgt>
          <document:FinInstnId>
            <document:Othr>
              <document:Id>{{BIC2}}</document:Id>
            </document:Othr>
          </document:FinInstnId>
        </document:InstgAgt>
        <document:InstdAgt>
          <document:FinInstnId>
            <document:Othr>
              <document:Id>{{BIC1}}</document:Id>
            </document:Othr>
          </document:FinInstnId>
        </document:InstdAgt>
      </document:GrpHdr>
      <document:TxInfAndSts>
        <document:OrgnlEndToEndId>{{OrgnlEndToEndId}}</document:OrgnlEndToEndId>
        <document:OrgnlGrpInf>
          <document:OrgnlMsgId>{{OrgnlMsgId}}</document:OrgnlMsgId>
          <document:OrgnlMsgNmId>pacs.008.001.10</document:OrgnlMsgNmId>
        </document:OrgnlGrpInf>
        <document:OrgnlTxId>{{OrgnlTxId}}</document:OrgnlTxId>
        <document:TxSts>ACSC</document:TxSts>
        <document:AccptncDtTm>
          {{AccptncDtTm}}
        </document:AccptncDtTm>
        <document:OrgnlTxRef>
          <document:IntrBkSttlmAmt Ccy="GNF">{{BkSttlmAmt}}</document:IntrBkSttlmAmt>
          <document:Amt>
            <document:InstdAmt Ccy="GNF">{{Amount}}</document:InstdAmt>
          </document:Amt>
          <document:Dbtr>
            <document:Nm>{{Nom}}</document:Nm>
            <document:PstlAdr>
              <document:AdrLine>{{AdrLine}}</document:AdrLine>
            </document:PstlAdr>
          </document:Dbtr>
          <document:DbtrAcct>
            <document:Id>
              <document:Othr>
                <document:Id>{{DbtrAcct_id}}</document:Id>
                <document:SchmeNm>
                  <document:Prtry>ACCT</document:Prtry>
                </document:SchmeNm>
              </document:Othr>
            </document:Id>
          </document:DbtrAcct>
          <document:CdtrAcct>
            <document:Id>
              <document:Othr>
                <document:Id>CdtrAcct_id</document:Id>
                <document:SchmeNm>
                  <document:Prtry>ACCT</document:Prtry>
                </document:SchmeNm>
              </document:Othr>
            </document:Id>
          </document:CdtrAcct>
        </document:OrgnlTxRef>
      </document:TxInfAndSts>
    </document:FIToFIPmtStsRpt>
  </document:Document>
</FPEnvelope>

what i really want is retrieve elements with {{}} and change thier content like {{SWITCH}} and replace it by his right content with my code, bellow is my code pls: i have created a method to read a xml file:

public XDocument readxml_file()
    {
        var path = Path.Combine(_hostingEnvironment.WebRootPath, "XmlTemplates/NotificationResponse.xml");
        XDocument doc =  XDocument.Load(path);
        
        //Console.WriteLine(doc);
        return doc;

    }

and i am reading the file like this:

XDocument response_document = readxml_file();

now i want to retrieve elements with those brackets {{}} but i cant. i have tried:

var xElement = response_document.XPathSelectElement("//FPEnvelope/header");
        var x = response_document.Descendants("header")
        .Where(ele => (string)ele.Attribute("id") == "{{SWITCH}}");

after filling all those brackets content i need to send a response xml.

please can someone help me, thanks for your time.

Answer 1

Try following :

       const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(FILENAME);
            XElement root = doc.Root;
            XNamespace ns = root.GetDefaultNamespace();
            XNamespace nsDocument = root.GetNamespaceOfPrefix("document");
            XNamespace nsHeader = root.GetNamespaceOfPrefix("header");
            XElement appHdr = doc.Descendants(nsHeader + "AppHdr").FirstOrDefault();
            XElement id = appHdr.Descendants(nsHeader + "Id").FirstOrDefault();
            id.SetValue("New Value");
 

        }