Question

From this XHTML source:

<div class = "page">  
<h1>UNIQUE NAME</h1>
  <table>
    <tbody>
      <tr>
        <td>DATA TO EXTRACT 1</td>
      </tr>
      <tr>
        <td />
        <td />
        <td />
        <td />
        <td />
        <td>DATA TO EXTRACT 2</td>
      </tr>
    </tbody>
 </table>
 etc...

There are multiple instances of UNIQUE NAME with a similar set of child elements.

I need to locate the UNIQUE NAME element and extract all values (DATA TO EXTRACT) within each of the child element tags. In addition, I need to keep a count of where each value is located. For example DATA TO EXTRACT 1 would be at tr 1, td 1. DATA TO EXTRACT 2 would be at tr 2, td 6.

I am new to linq to xml and I was wondering whether someone could point me in the right direction with regards to a strategy. I have managed to figure out how to get to the UNIQUE name element with the following code:

var choice1 = (from category in _data.Descendants("div")
                       where category.Element("h1").Value == "UNIQUE NAME"
                       select category).DescendantNodes();

This returns a set of the values, which I’m sure I could loop through but I’m sure there must be a more elegant way of achieving this goal.

Many thanks!

Answer 1

Here’s one way of doing it using LINQ:

var choice1 =
    from category in _data.Descendants("div")
    where category.Element("h1").Value == "UNIQUE NAME"
    from row in category.Descendants("tr").Select((element, index) => new { element, index })
    from col in row.element.Elements("td").Select((element, index) => new { element, index })
    where !string.IsNullOrEmpty(col.element.Value)
    select new
    {
        RowIndex = row.index + 1,   // one-based index
        ColIndex = col.index + 1,
        Value = col.element.Value,
    };

An example of how to use your results:

foreach (var v in choice1)
    Console.WriteLine(string.Format(
        "RowIndex = {0}, ColIndex = {1}, Value = \"{2}\".",
        v.RowIndex, v.ColIndex, v.Value));

…which would output:

RowIndex = 1, ColIndex = 1, Value = "DATA TO EXTRACT 1".
RowIndex = 2, ColIndex = 6, Value = "DATA TO EXTRACT 2".