Multiple elements with the same name, with multiple children

Question

I have come across a problem, I need to basicly deserialize this:

<?xml version="1.0" encoding="UTF-8"?>
<api_data>
  <status>ok</status>
  <sessions>
    <id>2</id>
    <sessionID>6bfd1f1a7e87a8a6ed476234ad1d6e86</sessionID>
    <gameID>1</gameID>
    <maxPlayers>8</maxPlayers>
    <hostIP>12.0.0.1</hostIP>
    <hostPort>1993</hostPort>
    <inProgress>0</inProgress>
    <timestamp>1358894690</timestamp>
  </sessions>
  <sessions>
    <id>3</id>
    <sessionID>eeb4dc2df32f885c2b7d13f28a246830</sessionID>
    <gameID>1</gameID>
    <maxPlayers>8</maxPlayers>
    <hostIP>12.0.0.1</hostIP>
    <hostPort>1993</hostPort>
    <inProgress>0</inProgress>
    <timestamp>1358894732</timestamp>
  </sessions>
</api_data>

And I need to convert that to usable data, its also dynamic, so there could be more than just 2 session elements, there could be 4, 20, or 0, the code I have now is just broken, and I was wondering whats a good method to get this to work?

Currently I am up to the point of the XDocument class, with all this loaded. And I need to return a multi-dimensional array with this data.

EDIT:

Current code, completely broken:

var xmlSessions = xmlDATA.Descendants("api_data").Elements("sessions").Select(x => x);

result = new string[xmlDATA.Descendants("api_data").Count(), 7];

EDIT 2: More info

The way I was thinking the MultiDimensional Array would be is as follows:

array[0,0] "ok" //Status
array[1,0 to 7] //First Session details go here
array[2,0 to 7] //Second session details go here, and so forth.

Answer 1

If you really only want a multidimensional array, you can obtain this from that XML with a single (somewhat long) line of code:

string[][] items = XDocument.Parse(xml).Root.Elements().Select(e => e.HasElements ? e.Elements().Select(ei => ei.Value).ToArray() : new string[]{ e.Value }).ToArray();

Or to make that same single statement a bit more readable:

string[][] items = 
    XDocument.Parse(xml).Root
             .Elements().Select(e => e.HasElements ? 
                 e.Elements().Select(ei => ei.Value).ToArray() : new string[]{ e.Value })
             .ToArray();

From that source XML, this would produce an array like this:

string[][]
{
   { "ok" },
   { "2", "6bfd1f1a7e87a8a6ed476234ad1d6e86", "1", "8", "12.0.0.1", "1993", "0", "1358894690" },
   { "3", "eeb4dc2df32f885c2b7d13f28a246830", "1", "8", "12.0.0.1", "1993", "0", "1358894732" }
}

If you want to get the status separately, and put the other values in a multidimensional array, you could do this:

XDocument doc = XDocument.Parse(xml);
string status = doc.XPathSelectElement("/*/status").Value;
string[][] items = 
    doc.Root.Elements().Where(e => e.HasElements)
       .Select(e => e.Elements().Select(ei => ei.Value).ToArray()).ToArray();

This would produce the same as above, except status would be an individual string, and items would not have the first single-element array in it:

string[][]
{
   { "2", "6bfd1f1a7e87a8a6ed476234ad1d6e86", "1", "8", "12.0.0.1", "1993", "0", "1358894690" },
   { "3", "eeb4dc2df32f885c2b7d13f28a246830", "1", "8", "12.0.0.1", "1993", "0", "1358894732" }
}

Answer 2

You can define the following class representations:

public class api_data
{
    public string status { get; set; }

    [XmlElement]
    public session[] sessions { get; set; }
}

public class session
{
    public int id { get; set; }
    public string sessionID { get; set; }
    public int gameID { get; set; }
    public int maxPlayers { get; set; }
    public string hostIP { get; set; }
    public int hostPort { get; set; }
    public int inProgress { get; set; }
    public int timestamp { get; set; }
}

The key is the [XmlElement] tag on the sessions property, that will instruct the XmlSerializer to read/write XML using the schema sample you provided. To deserialize it, you can use the XmlSerializer as such:

//this might change, not sure how you obtain your xml, 
//but let's assume you already have it available as a string
byte[] xmlBytes = System.Text.Encoding.UTF8.GetBytes(xmlData); 

var stream = new MemoryStream(xmlBytes);
XmlSerializer serializer = new XmlSerializer(typeof(api_data));
api_data apidata = (api_data)serializer.Deserialize(stream);

Don't need any more XML adornment or setup than that to read it in (tested and working).

EDIT: Though you may want to consider using some other XML attributes to transfer to some nicer naming conventions, and we can also List<Session> to boot instead of an array:

[XmlRoot("api_data")]
public class ApiData
{
    [XmlElement("status")]
    public string Status { get; set; }

    [XmlElement("sessions")]
    public List<Session> Sessions { get; set; }
}

public class Session
{
    [XmlElement("id")]
    public int ID { get; set; }

    [XmlElement("sessionID")]
    public string SessionID { get; set; }

    [XmlElement("gameID")]
    public int GameID { get; set; }

    [XmlElement("maxPlayers")]
    public int MaxPlayers { get; set; }

    [XmlElement("hostIP")]
    public string HostIP { get; set; }

    [XmlElement("hostPort")]
    public int HostPort { get; set; }

    [XmlElement("inProgress")]
    public int InProgress { get; set; }

    [XmlElement("timestamp")]
    public int TimeStamp { get; set; }
}

EDIT: Just noticed that you need to turn this into a multidimensional array (not sure why, but you specify that's legacy). Well at this point, you have a nice object model from which you can do this data transfer. Not sure how you do the typing, but let's just assuming object type array for now:

ApiData apiData = DeserializeMyApiData(); // from above
array[0][0] = apiData.Status;
for(int i = 1; i <= apiData.Sessions.Count; i++)
{
    var session = apiData.Sessions[i - 1];
    array[i] = new object[8];
    array[i][0] = session.ID;
    array[i][1] = session.SessionID;
    array[i][2] = session.GameID;
    array[i][3] = session.MaxPlayers;
    array[i][4] = session.HostIP;
    array[i][5] = session.HostPort;
    array[i][6] = session.InProgress;
    array[i][7] = session.TimeStamp;
}

That will go through and build up your array regardless of how many sessions you have.

Answer 3

Can you wrap the 'sessions' tags inside a 'session_list' tag?

If so you could use something like this to load it:

public class api_data {

    public class sessions {
        public string id { get; set; }
        public string sessionID { get; set; }
        // put all the other vars in here ...
    }

    public string status { get; set; }           
    public List<sessions> session_list { get; set; }

    public static api_data LoadFromXML(string xmlFile) {

        api_data localApiData;

        // serialize from file
        try {
            var xs = new XmlSerializer(typeof(api_data),
                     new XmlRootAttribute("api_data"));
            using (TextReader tr = new StreamReader(xmlFile)) {
                localApiData= xs.Deserialize(tr) as api_data;
            }
        }
        catch (Exception ex) {
            Log.LogError(string.Format(
               "Error reading api_data file {0}: {1}",
               xmlFile, ex.Message));
            return null;
        }


        return localApiData;
    }
}

If you cannot change the format of the xml file, you might need to load the status in it's own step and then load the sessions as if the api-data was the list variable, although the fact the status is there, might give you an error.