Question

I have the following code in C# and .net 3.5 that is working fine but need to know if this can be simplified may be using Linq or something else? Basically I am reading a xml file to get the column names. And then try to copy the columns and the sequence attribute in a dictionary object if “isactive attribute of the column is “true”. I use this dictionary object in other part of code. I loop through elements and then attributes and look for the columns that are active, if active I store the sequence and finally add the column and the sequence to the dictionary.

var doc = XDocument.Load("DataStructure.xml");
var cols = doc.XPathSelectElements("/datastructure/" + sPageName + "/columns");
Dictionary<string, int> columns = new Dictionary<string, int>();
bool bAddData = true;
int sSequence = 0;

foreach (var col in cols.Elements())
{
    foreach (XAttribute at in col.Attributes())
    {
        if (at.Name.ToString().ToLower().Equals("isactive") && at.Value.ToString() != "true")
        {
            bAddData = false;
            break;
        }

        bAddData = true;                    
        if (at.Name.ToString().ToLower().Equals("sequence"))
        {
            sSequence = Convert.ToInt32(at.Value.ToString());
            break;
        }
    }
    if (bAddData)
    {
        columns.Add(col.Name.ToString(), sSequence);
    }
}

I am sure this is pretty poor code but I would like to know how can I improve it. Here is the xml data file. I am ok if I need to restructure the xml to make this simple.

<?xml version="1.0" encoding="utf-8" ?>
<datastructure>
  <MyPage>
    <columns>
      <number isactive="true" sequence="1" />
      <curr_code isactive="true" sequence="2" />
      <curr_desc isactive="true" sequence="3" />
      <tradecurrvalue isactive="true" sequence="4" />
      <selectcurrvalue isactive="true" sequence="5" />
    </columns>    
  </MyPage>
</datastructure>

Answer 1

I think that this should do it:

var doc = XDocument.Load("DataStructure.xml");
var cols = doc.XPathSelectElements("/datastructure/" + sPageName + "/columns");

Dictionary<string, int> columns =
  cols.Elements()
  .Where(c => c.Attribute("isactive").Value == "true")
  .ToDictionary(
    c => c.Name.ToString(),
    c => Int32.Parse(c.Attribute("sequence").Value)
  );

Edit:

Out of curiosity I wanted to find out what could be done about the original code without using LINQ once I figured out what it acutally did and how to best use the methods in the XElement class, and I arrived at this:

var doc = XDocument.Load("DataStructure.xml");
var cols = doc.XPathSelectElements("/datastructure/" + sPageName + "/columns");
Dictionary<string, int> columns = new Dictionary<string, int>();

foreach (var col in cols.Elements()) {
  if (col.Attribute("isactive").Value == "true") {
    columns.Add(col.Name.ToString(), Int32.Parse(col.Attribute("sequence").Value));
  }
}