LINQ Reporting Engine - How to get a list of report tags

I am trying create a routine that pre-processes a template to verify that all entered LINQ reports tags exist in the data sets available. (when I say report tags I mean this: <<[ColumnName]>>)
Is anyone able to tell me if there is a method or filter I can pass to the document GetChildNodes method to get this information? (StructuredDocumentTag does not work)

@jonathan.newman83

Unfortunately, LINQ Reporting Engine does not provide such functionality at the moment. This feature was already requested, it was logged as WORDSNET-17454, but for now, its development is postponed. You will be notified through the forum thread, once it is implemented.

As a workaround, to find contents of simple expression tags, you can use Range.Replace functionality on a template document (without actual replacing) as follows:

DocumentBuilder builder = new DocumentBuilder();
builder.Write("Some text <<[Column1]>>, more text <<[Column2]>>, and some more text.");

ColumnNameCollector collector = new ColumnNameCollector();
Regex regex = new Regex(@"<<\[(.*?)\]>>");

builder.Document.Range.Replace(regex, "", new FindReplaceOptions(collector));

foreach (string columnName in collector.ColumnNames)
    Console.WriteLine(columnName);

Console.WriteLine(builder.Document.GetText().Trim()); // Prints the same text, it is not replaced.
internal class ColumnNameCollector : IReplacingCallback
{
    public ReplaceAction Replacing(ReplacingArgs args)
    {
        ColumnNames.Add(args.Match.Groups[1].Value);

        // We do not want to replace anything, so skip the match.
        return ReplaceAction.Skip;
    }

    internal List<string> ColumnNames { get; } = new List<string>();
}