CODEWITHSUNDEEP
c#.netjsonjson.net
Mark Bell
Mark Bell

Reputation: 29785

How do I save a JSON file with four spaces indentation using JSON.NET?

I need to read a JSON configuration file, modify a value and then save the modified JSON back to the file again. The JSON is as simple as it gets:

{
    "test": "init",
    "revision": 0
}

To load the data and modify the value I do this:

var config = JObject.Parse(File.ReadAllText("config.json"));
config["revision"] = 1;

So far so good; now, to write the JSON back to the file. First I tried this:

File.WriteAllText("config.json", config.ToString(Formatting.Indented));

Which writes the file correctly, but the indentation is only two spaces.

{
  "test": "init",
  "revision": 1
}

From the documentation, it looks like there's no way to pass any other options in using this method, so I tried modifying this example which would allow me to directly set the Indentation and IndentChar properties of the JsonTextWriter to specify the amount of indentation:

using (FileStream fs = File.Open("config.json", FileMode.OpenOrCreate))
{
    using (StreamWriter sw = new StreamWriter(fs))
    {
        using (JsonTextWriter jw = new JsonTextWriter(sw))
        {
            jw.Formatting = Formatting.Indented;
            jw.IndentChar = ' ';
            jw.Indentation = 4;

            jw.WriteRaw(config.ToString());
        }
    }
}

But that doesn't seem to have any effect: the file is still written with two space indentation. What am I doing wrong?

Upvotes: 21

Views: 13239

Answers (6)

Игорь Бондарев
Игорь Бондарев

Reputation: 1

If you don`t have a class to serialize/deserialize your JSON object, you may use JObject from Newtonsoft.Json.Linq

var buildText = JObject.Parse(buildInfo.ToString());
File.WriteAllText(infoPath, buildText.ToString());

As a result you will have fully formatted .json file

Upvotes: -1

huha
huha

Reputation: 4255

I summarize the complete code, based on @Guffa's answer.

Changed from FileMode.OpenOrCreate to FileMode.Create. Otherwise the file will not be shortened when the new contents are smaller.

var config = JObject.Parse(File.ReadAllText("config.json"));
config["revision"] = 1;

using (FileStream fs = File.Open("config.json", FileMode.Create))
{
    using (StreamWriter sw = new StreamWriter(fs))
    {
        using (JsonTextWriter jw = new JsonTextWriter(sw))
        {
            jw.Formatting = Formatting.Indented;
            jw.IndentChar = ' ';
            jw.Indentation = 4;

            JsonSerializer serializer = new JsonSerializer();
            serializer.Serialize(jw, config);
        }
    }
}

Upvotes: 0

Damian Drygiel
Damian Drygiel

Reputation: 18025

Here you have an extension method that makes json easy to read for human. It removes quotes in property names, converts enums to strings and indent json with 4 spaces.

public static string ToPrettyJson(this object obj)
{
    var json = JsonConvert.SerializeObject(obj, Formatting.Indented, new StringEnumConverter());
    json = Regex.Replace(json, @"^([\s]+)""([^""]+)"": ", "$1$2: ", RegexOptions.Multiline); // no quotes in props
    json = Regex.Replace(json, @"^[ ]+", m => new String(' ', m.Value.Length * 2), RegexOptions.Multiline); // more indent spaces
    return json;
}

Upvotes: -1

Warnecke
Warnecke

Reputation: 81

I ran into the same issue and found out that WriteRaw does not effect the indentation settings, however you can solve the issue using WriteTo on the JObject

using (FileStream fs = File.Open("config.json", FileMode.OpenOrCreate))
{
    using (StreamWriter sw = new StreamWriter(fs))
    {
        using (JsonTextWriter jw = new JsonTextWriter(sw))
        {
            jw.Formatting = Formatting.Indented;
            jw.IndentChar = ' ';
            jw.Indentation = 4;

            config.WriteTo(jw);
        }
    }
}

Upvotes: 8

Jack
Jack

Reputation: 100

Maybe try to feed a tab character to the IndentChar?

...    
jw.IndentChar = '\t';
...

Accordinging to the documentation, it should use the tab character to indent the JSON instead of the space character. http://james.newtonking.com/json/help/index.html?topic=html/T_Newtonsoft_Json_Formatting.htm

Upvotes: 1

Guffa
Guffa

Reputation: 700650

The problem is that you are using config.ToString(), so the object is already serialised into a string and formatted when you write it using the JsonTextWriter.

Use a serialiser to serialise the object to the writer instead:

JsonSerializer serializer = new JsonSerializer();
serializer.Serialize(jw, config);

Upvotes: 16

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