XML & LINQ

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XML

<?xml version="1.0" encoding="utf-8"?>
<Controllers>
  <PLC ConfigName="OP010">
    <IPAddress>172.21.1.1</IPAddress>
    <SubnetMask>255.255.255.0</SubnetMask>
    <ENxT_Slot>1</ENxT_Slot>
    <CPU_Slot>0</CPU_Slot>
    <ProgName>OP010_ePRESS</ProgName>
    <CurveTag>Curve</CurveTag>
    <CommTimeOut>1000</CommTimeOut>
    <UpdateRate>250</UpdateRate>
  </PLC>
    <PLC ConfigName="OP020">
    <IPAddress>172.21.1.2</IPAddress>
    <SubnetMask>255.255.254.0</SubnetMask>
    <ENxT_Slot>1</ENxT_Slot>
    <CPU_Slot>0</CPU_Slot>
    <ProgName>OP020_ePRESS</ProgName>
    <CurveTag>Curve</CurveTag>
    <CommTimeOut>1000</CommTimeOut>
    <UpdateRate>250</UpdateRate>
  </PLC>
</Controllers>

I'm taking a swag at LINQ with XML with VS2010 and C#. Using the XML shown above, I've got the following code to pull the XElements out of the XML this way -

C#

var xmlElemList = from xmlElements in XElement.Load(@"configuration.xml").Elements("PLC") select xmlElements;

      foreach (var xmlElem in xmlElemList)
      {

I can iterate through each element with a foreach, I can print the contents to the console. I can pull out the attribute from the <plc configname="OPxxx">. What I can't figure out how to do is either 1) Map the data into a class object I have with properties of the same name, or at the very least 2) assign the descendants of each <plc configname...=""> to variables without using a very painful process such as what I post below. There has got to be an easier way.

What does work (UGLY!!!) is the following -

Create a set of delimiters for each set of data -

C#

String[] ip_addr_delim = new String[2] { "</IPAddress>", "<IPAddress>" };
      String[] sub_net_delim = new String[2] { "<SubnetMask>", "</SubnetMask>" };
      String[] comm_slot_delim = new String[2] { "<ENxT_Slot>", "</ENxT_Slot" };
      String[] cpu_slot_delim = new String[2] { "<CPU_Slot>", "</CPU_Slot>" };
      String[] prog_name_delim = new String[2] { "<ProgName>", "</ProgName>" };
      String[] curve_tag_delim = new String[2] { "<CurveTag>", "</CurveTag>" };
      String[] timeout_delim = new String[2] { "<CommTimeOut>", "</CommTimeOut>" };
      String[] update_rate_delim = new String[2] { "<UpdateRate>", "</UpdateRate>" };

Then iterate through them all, creating a PLC class object, assigning values, then adding..rinse and repeat. I can't believe there isn't a much more elegant solution.

C#

// Execute the query
      foreach (var xmlElem in xmlElemList)
      {
        string[] temp;

        ActiveCfg.ConfigName = xmlElem.FirstAttribute.Value.ToString();

        temp = xmlElem.ToString().Split(ip_addr_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.IPAddress = temp[1];

        temp = xmlElem.ToString().Split(sub_net_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.SubnetMask = temp[1];

        temp = xmlElem.ToString().Split(comm_slot_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.ENxT_Slot = Convert.ToByte(temp[1]);

        temp = xmlElem.ToString().Split(cpu_slot_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.CPU_Slot = Convert.ToByte(temp[1]);

        temp = xmlElem.ToString().Split(prog_name_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.ProgName = temp[1];

        temp = xmlElem.ToString().Split(curve_tag_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.CurveTag = temp[1];

        temp = xmlElem.ToString().Split(timeout_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.CommTimeOut = Convert.ToInt32(temp[1]);

        temp = xmlElem.ToString().Split(update_rate_delim, StringSplitOptions.RemoveEmptyEntries);
        ActiveCfg.UpdateRate = Convert.ToInt32(temp[1]);

        PLC_List.Add(this.ActiveCfg);

      }

I should add that I am free to change the XML format in the .XML to fit my needs so if that makes something easier without breaking rules of XML, I'm open to it.

Posted 24-Jan-11 10:21am

jlsmith1001

Updated 24-Jan-11 10:43am

v4

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3 solutions

Solution 1

some copy paste code from a test project:
it's old and ugly, but: Have a look at the "Value" property ;)

C#

XDocument xmlDoc = XDocument.Load(fileName);
try
{
    //
    //
    // get origins from project file
    var Origins = from Origin in xmlDoc.Descendants("Origin")
        select new
        {
            name = Origin.Element("Name").Value,
            tx = Origin.Element("X").Value,
            ty = Origin.Element("Y").Value,
            tz = Origin.Element("Z").Value,
            id = Origin.Element("ID").Value,
        };

    foreach (var tmp in Origins)
    {
        // create new origin object
        OriginObject origin = new OriginObject();
        origin.X = double.Parse(tmp.tx);
        origin.Y = double.Parse(tmp.ty);
        origin.Z = double.Parse(tmp.tz);
        origin.ID = int.Parse(tmp.id);
        origin.Name = tmp.name;
        // add the origin to the collection
        this.OriginsCollection.Add(origin.Name, origin);
    }
}
catch(Exception e)
{
    System.Diagnostics.Debug.Print(
        "Error while reading:{0}\n{1}", e.Message, e.StackTrace);
}

Posted 24-Jan-11 10:52am

gammagtmw

Updated 24-Jan-11 10:53am

v2

Solution 2

Thanks much for the answer! I just figured out what appears to be a nice way to do it by putting together a couple of things I saw on MSDN. I know I looked at the same page at least 5 times today... There may be a cleaner way, but this seems to work well -

XML

// Create the query
      var xmlElemList = from xmlElements
                        in XElement.Load(@"configuration.xml").Elements("PLC")
                        select xmlElements;

      foreach (var xmlElem in xmlElemList.OfType<XElement>())
      {
        cPLC plc = new cPLC();
        plc.ConfigName = (string)xmlElem.FirstAttribute.Value;
        plc.IPAddress = (string)xmlElem.Element("IPAddress");
        plc.SubnetMask = (string)xmlElem.Element("SubnetMask");
        plc.CommSlot = (Int32)xmlElem.Element("CommSlot");
        plc.CpuSlot = (Int32)xmlElem.Element("CpuSlot");
        plc.ProgName = (string) xmlElem.Element("ProgName");
        plc.CurveTag = (string) xmlElem.Element("CurveTag");
        plc.CommTimeOut = (Int32) xmlElem.Element("CommTimeOut");
        plc.UpdateRate = (Int32) xmlElem.Element("UpdateRate");
        plcList.Add(plc);
      }

Posted 24-Jan-11 12:26pm

jlsmith1001

Updated 24-Jan-11 12:27pm

v2

Comments

Christian Graus 24-Jan-11 19:46pm

Please don't push 'answer' to add a comment. Use 'comment'.

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Christian Graus · Accepted Answer · 2011-01-24T13:48:00

There is an easier way.

C#

XDocument xmlDoc = XDocument.Load(path);
var videos = from video in xmlDoc.Descendants("video")
             select new
             {
                 FilePath = video.Attribute("filepath").Value,
                 ThumbPath = video.Attribute("thumbpath").Value,
                 RolloverPath = video.Attribute("rolloverimage").Value,
                 Index = Convert.ToInt32(video.Attribute("index").Value),
                 Title = video.Attribute("title").Value,
                 IsDog = Convert.ToBoolean(video.Attribute("isdog").Value),
                 IsCat = Convert.ToBoolean(video.Attribute("iscat").Value),
                 IsHorse = Convert.ToBoolean(video.Attribute("ishorse").Value)
             };

This code will create a collection of objects with the properties I name. Now I can iterate over that and use it to set the values of my strongly typed/named class in my code.

XML & LINQ

3 solutions

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XML & LINQ

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