Querying an XML log with LINQ

Question

I am logging all changes to a folder with with FileWatcher to an XML file with

XDocument log = XDocument.Load(logpath);
XElement change = new XElement("change");
change.Add(new XAttribute("datetime", stamp));
change.Add(new XAttribute("status", "Deleted"));
change.Add(new XAttribute("filename", filepath));


log.Add(change);
log.Save(logpath);

Then, when I want to look at the changes made by a certain timestamp, I query it with

var query = _filelog.Elements().Where(x => ((DateTime)x.Element("datetime")) <= time);

Which is just an IEnumerable of XElements and not very convenient to work with. How can I turn it into a more convenient collection such as list of dictionaries of keyvaluepairs status : "deleted" etc? There is a different amount of XAttributes in the XElements depending on the type of change.

Additionally, is there a way to query a last change for every filename until the timestamp rather than every change up to and including that point?

Answer 1

Try one of solutions below. First is if DateTime is unique, second is if there are duplicate DateTime values.

            Dictionary<DateTime, XElement> dict1 = doc.Elements("change")
                .GroupBy(x => DateTime.Parse(x.Attribute("datetime").Value), y => y)
                .ToDictionary(x => x.Key, y => y.FirstOrDefault());

            Dictionary<DateTime, List<XElement>> dict2 = doc.Elements("change")
                .GroupBy(x => DateTime.Parse(x.Attribute("datetime").Value), y => y)
                .ToDictionary(x => x.Key, y => y.ToList());