Question

I want to use Linq to extract data from an XML document and place it into a list

<Data>
<FlightData DTS="20110216 17:17" flight="1234" origin="CYYZ" dest="CYUL" aircraft="945">
    <TLDRequest>
        <Airline>ABC</Airline>
        <AcReg>C-FABC</AcReg>
        <CalcType>T</CalcType>
        <OAT>-05</OAT>
        <Wind>060/10</Wind>
        <Flaps>5</Flaps>
        <Switches></Switches>
        <Runways>
            <Rwy>6L</Rwy>
            <Rwy>6R</Rwy>
        </Runways>
        ...
     </TLDRequest>
    ...
  </FlightData>
</Data>

My Linq code in C# works – I can get attributes from the FlightData tab, but I think it could be more efficient, especially in the area of getting data from the TLDRequest tag. Can I get some insight on using best practices to get to and grab child tags?

 public static List<ACARS_Phase> createAcarsPhaseObject(XDocument xDoc)
    {
        return (from ao in xDoc.Descendants("FlightData")
                select new ACARS_Phase
                {
                    FlightDate = DateTime.ParseExact(ao.Attribute("DTS").Value, "yyyyMMdd HH:mm", new CultureInfo("en-CA")),
                    FlightNumber = ao.Attribute("flight").Value,
                    Origin = ao.Attribute("origin").Value,
                    Destination = ao.Attribute("dest").Value,
                    InternalFinNumber = ao.Attribute("aircraft").Value,

                    OperatorCode = ao.Element("TLDRequest").Element("Airline").Value,
                    RegistrationNumber = ao.Element("TLDRequest").Element("AcReg").Value,
                    Wind = ao.Element("TLDRequest").Element("Wind").Value,
                    Flaps = ao.Element("TLDRequest").Element("Flaps").Value,
                    OAT = ao.Element("TLDRequest").Element("OAT").Value,
                }).ToList();
    }

Best regards

Answer 1

Your query is fine, generally speaking. If you want to cut down on some of the redundancy, consider using let to get the TLDRequest element once, so you repeat yourself a bit less.

return (from ao in xDoc.Descendants("FlightData")
        let request = ao.Element("TLDRequest")
        select new AcARS_Phase 
        {
              // stuff
              OperatorCode = request.Element("Airline").Value,
              RegistrationNumber = request.Element("AcReg").Value,
              // etc.
        }).ToList();