Deep find or search the key at any level in JSON and replace its value in c#

Question

I am also struck in a sort of problem. I am able to convert the nested JSON into key-Value , but Now I want to convert it into back its orignal json format. As of my problem I can't use the C# Object Model to do this, because the JSON file that I have is dynamic and its structure changes over the period of time. So I am looking for the solution by which we can serialize and deserialize the JSON via updated Key-Value pair. Any help would be great relief. TIA.

Sample JSON Code:

 {
  "firstName": "John",
  "lastName": "Smith",
  "isAlive": true,
  "age": 25,
  "address": {
  "streetAddress": "21 2nd Street",
  "city": "New York",
  "state": "NY",
  "postalCode": "10021-3100"
 },
"phoneNumbers": [
{
  "type": "home",
  "number": "212 555-1234"
 },
{
  "type": "office",
  "number": "646 555-4567"
},
{
  "type": "mobile",
  "number": "123 456-7890"
}
],
"children": [],
"spouse": null

}

var obj = JObject.Parse(json);

var result = obj.Descendants()
.OfType()
.Select(p => new KeyValuePair(p.Path,
    p.Value.Type == JTokenType.Array || p.Value.Type == JTokenType.Object
        ? null : p.Value));

foreach (var kvp in result)
  Console.WriteLine(kvp);

The output of this code is coming like this :

[firstName, John]
[lastName, Smith]
[isAlive, True]
[age, 25]
[address, ]
[address.streetAddress, 21 2nd Street]
[address.city, New York]
[address.state, NY]
[address.postalCode, 10021-3100]
[phoneNumbers, ]
[phoneNumbers[0].type, home]
[phoneNumbers[0].number, 212 555-1234]
[phoneNumbers[1].type, office]
[phoneNumbers[1].number, 646 555-4567]
[phoneNumbers[2].type, mobile]
[phoneNumbers[2].number, 123 456-7890]
[children, ]
[spouse, ]

I want to convert it into back its original JSON structure.

user_5514820 · Answer

The below ExtensionMethods can help you to update any key value in your json on any level.

public static class JsonExtensions
{
    public static void SetByPath(this JToken obj, string path, JToken value)
    {
        JToken token = obj.SelectToken(path);
        token.Replace(value);
    }

    public static List FindTokens(this JToken containerToken, string name)
    {
        List matches = new List();
        FindTokens(containerToken, name, matches);
        return matches;
    }

    private static void FindTokens(JToken containerToken, string name, List matches)
    {
        if (containerToken.Type == JTokenType.Object)
        {
            foreach (JProperty child in containerToken.Children())
            {
                if (child.Name == name)
                {
                    matches.Add(child.Value);
                }
                FindTokens(child.Value, name, matches);
            }
        }
        else if (containerToken.Type == JTokenType.Array)
        {
            foreach (JToken child in containerToken.Children())
            {
                FindTokens(child, name, matches);
            }
        }
    }
}

And here I write one custom function that find the key and replace it's value,

public static JToken FindAndReplace(JToken jToken, string key, JToken value, int? occurence)
{
    var searchedTokens = jToken.FindTokens(key);
    int count = searchedTokens.Count;

    if (count == 0)
        return $"The key you have to serach is not present in json, Key: {key}";

    foreach (JToken token in searchedTokens)
    {
        if (!occurence.HasValue)
            jToken.SetByPath(token.Path, value);
        else
        if (occurence.Value == searchedTokens.IndexOf(token))
            jToken.SetByPath(token.Path, value);
    }

    return jToken;
}

Important: What's the fourth parameter occurence mean here?

If you put null in this parameter then the value will be updated for all the occurrences of the specified key in json at any level.
If you put any index like 0, 1 then the value will be updated for the specified index of the specified key in json at any level.

And you can use it like

string json = File.ReadAllText(@"Path to your json file");

JToken jToken = JToken.Parse(json);

jToken = FindAndReplace(jToken, "firstName", "Matthew", null);
jToken = FindAndReplace(jToken, "lastName", "Gilbert", null);
jToken = FindAndReplace(jToken, "streetAddress", "Falcon Ave, 91 Street, New Jersey", null);
jToken = FindAndReplace(jToken, "postalCode", "R12H34", null);

jToken = FindAndReplace(jToken, "type", "work", 0);
jToken = FindAndReplace(jToken, "number", "787-878-7878", 0);

jToken = FindAndReplace(jToken, "type", "factory", 1);
jToken = FindAndReplace(jToken, "number", "989-898-9898", 1);

string outputJson = jToken.ToString();

Output:

Reference: Brian Rogers, senshin

Deep find or search the key at any level in JSON and replace its value in c#

1 Answers