Search for a nested value inside of a JSON.net object in C#

Question

I\'ve got a JSON stream coming back from a server, and I need to search for a specific value of the node \"ID\" using JSON.net to parse the data. And I can almost make it wo

Answer 1

Simply write a recursive function:

private Thing FindThing(Thing thing, string name)
{
    if (thing.name == name)
        return thing;
    foreach (var subThing in thing.childFolders.Concat(thing.childComponents))
    {
        var foundSub = FindThing(subThing, name);
        if (foundSub != null)
            return foundSub;
    }
    return null;
}

class RootObject
{
    public Thing data { get; set; }
}

class Thing
{
    public int id { get; set; }
    public string name { get; set; }
    public List<Thing> childFolders { get; set; } = new List<Thing>();
    public List<Thing> childComponents { get; set; } = new List<Thing>();
}

And using it:

var obj = JsonConvert.DeserializeObject<RootObject>(jsonString);
var result = FindThing(obj.data, "route3");

Answer 2

My ultimate goal is to be able to search for "route3" and get back 19007

You can use linq and Descendants method of JObject to do it:

var dirs = JObject.Parse(json)
            .Descendants()
            .Where(x=>x is JObject)
            .Where(x=>x["id"]!=null && x["name"]!=null)
            .Select(x =>new { ID= (int)x["id"], Name = (string)x["name"] })
            .ToList();

var id = dirs.Find(x => x.Name == "route3").ID;

Answer 3

You can use the SelectToken or SelectTokens functions to provide a JPath to search for your desired node. Here is an example that would provide you the route based on name:

JObject.Parse(jsonData)["data"].SelectToken("$..childComponents[?(@.name=='route3')]")

You can find more documentation on JPath here