Serialize flat Dictionary into multi-sub-object JSON

Question

In C# I have a flat Dictionary<string, string> where keys are in form of obj1/obj2/obj3 and values are direct string. Now I want to serialize that into subobjects, so example values:

var dict = new Dictionary<string, string> { {"foo/bar/baz1", "123" }, {"foo/baz", "456" }, { "foo/abc", "def" } };

should result with:

{
     "foo": {
         "bar": {
             "baz1": "123"
         },
         "baz": "456",
         "abc": "def"
     }
}

Optionally I want to remove quotes around "123" and "456" in output if they can be interpreted as numbers or booleans.

I am using Newtonsoft.JSON

Answer 1

You can parse a source dictionary into JObject using JObject.FromObject method. Then go through all of properties, split them using string.Split and parse recursively to a new JObject, representing a properties tree. Finally add this object to the destination one using JObject.Add, or update it if the given key is already exist

var dict = new Dictionary<string, string> { { "foo/bar/baz1", "123" }, { "foo/baz", "456" }, { "foo/abc", "def" } };
var source = JObject.FromObject(dict);
var dest = new JObject();

foreach (var property in source.Properties())
{
    //split the name into parts
    var items = property.Name.Split(new[] { "/" }, StringSplitOptions.RemoveEmptyEntries);
    var item = items.FirstOrDefault();
    if (string.IsNullOrEmpty(item))
        continue;

    //get JObject representing a properties tree
    var result = WriteItems(items.Skip(1).ToList(), property.Value);

    //check that destination already contains top property name (e.g. 'foo')
    if (dest.ContainsKey(item))
    {
        (dest[item] as JObject)?.Add(result.First);
    }
    else
    {
        dest.Add(item, result);
    }
}

Console.WriteLine(dest.ToString());

//local function to recursively go through all properties and create a result JObject
JObject WriteItems(IList<string> items, JToken value)
{
    var item = items.FirstOrDefault();
    items.RemoveAt(0);

    if (!items.Any()) //no more items in keys, add the value
        return new JObject(new JProperty(item, value));

    return new JObject(new JProperty(item, WriteItems(items, value)));
}

It produces the following output

{
  "foo": {
    "bar": {
      "baz1": "123"
    },
    "baz": "456",
    "abc": "def"
  }
}

Also, the code above allows you to handle a properties tree with any depth. I don't think that there is a built-in way to serialize the structure like foo/bar/baz1 into sub-objects in Json.NET