Get another attribute on the same element by searching another attribute

This might be the simplest question for that i appologise. This is part of my xml. What i want to get is the attribute "Value" based on another attribute "ItemOID". IE when ItemOID="I_MEDIC_HISTORY_INDICATION" what is the value.

<FormData FormOID="F_NEUROLOGICAL_V20" OpenClinica:Version="V2.0" OpenClinica:Status="initial data entry">
    <ItemGroupData ItemGroupOID="IG_NEURO_UNGROUPED" ItemGroupRepeatKey="1" TransactionType="Insert">
        <ItemData ItemOID="I_NEURO_NEURO_TENDONAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_TENDON" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_GAITAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_GAIT" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_COORDINATEAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_COORDINATE" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_SENSORYAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_SENSORY" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_MUSCLETONEAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_MUSCLETONE" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_MOTORAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_MOTOR" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_CRANIALAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_CRANIAL" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_SPEECHAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_SPEECH" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_BEHAVEAB" Value="abnormal" />
        <ItemData ItemOID="I_NEURO_NEURO_BEHAVE" Value="0" />
        <ItemData ItemOID="I_NEURO_NEURO_APPEARAB" Value="" />
        <ItemData ItemOID="I_NEURO_NEURO_APPEAR" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_NORMAL" Value="1" />
        <ItemData ItemOID="I_NEURO_NEURO_DATE" Value="2014-10-10" />
    </ItemGroupData>
</FormData>

This is my code. As you can tell i am a bit stuck. 

string neuroExamPath = "//oc:FormData[@FormOID='F_NEUROLOGICAL_V20']/oc:ItemGroupData/oc:ItemData";
var neuroExamList = doc.XPathSelectElements(neuroExamPath, nsmgr).Reverse();

foreach (var neuroExamElement in neuroExamList)
{
    var patrow = patDt.NewRow();
    var I_NEURO_NEURO_NORMAL = neuroExamElement.Attribute("Value").Value;
    patrow["Neuro_normal"] = I_NEURO_NEURO_NORMAL;
    var I_NEURO_NEURO_APPEAR = neuroExamElement.Attribute("Value").Value;
    patrow["Neuro_appear"] = I_NEURO_NEURO_APPEAR;
    var I_NEURO_NEURO_APPEARAB = neuroExamElement.Attribute("Value").Value;
    patrow["Neuro_appearab"] = I_NEURO_NEURO_APPEARAB;

    patDt.Rows.Add(patrow);
}

As you can tell it will iterate all the attribute Value all the time. However i need var I_NEURO_NEURO_NORMAL = neuroExamElement.Attribute("Value").Value; line to have a condition where ItemOID="I_NEURO_NEURO_NORMAL" and so on. So i can put one attribute at a time into a datatable. Please help. Thank you.

Jon Skeet
people
quotationmark

It looks to me like you want a new row for each ItemGroupData element, not each ItemData element. I would expect something like:

foreach (var itemGroup in doc.Root.Elements("ItemGroupData"))
{
    var row = patDt.NewRow();
    row["Neuro_normal"] = itemGroup.ExtractValue("I_NEURO_NEURO_NORMAL");
    row["Neuro_appear"] = itemGroup.ExtractValue("I_NEURO_NEURO_APPEAR");
    row["Neuro_appearab"] = itemGroup.ExtractValue("I_NEURO_NEURO_APPEARAB");
    patDt.Rows.Add(row);
}

which uses a new extension method:

public static string ExtractValue(this XElement parent, string oid)
{
    return parent.Elements("ItemData")
                 .Where(x => x.Attribute("ItemOID").Value == oid)
                 .First()
                 .Attribute("Value")
                 .Value;
}

Alternatively, if you're extracting a lot of the attributes, you could build a dictionary:

var values = itemGroup.Elements("ItemData")
                      .ToDictionary(x => x.Attribute("ItemOID").Value,
                                    x => x.Attribute("Value").Value);

people

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