Remove Properties with Value Equal to Zero in JSON String

Question

Hi, Everybody!...

I have a JSON string I need to alter before it gets sent as part of a request. I wish to remove any instances where the following string is encountered:

"<property>":0

where <property> is a placeholder for a property (e.g., "height":0, "width":0, "length":0, etc.). In other words, <property> is not a literal.

However, I do not wish any of the following to be removed (e.g., "height":0.1, "width":0.2, "length":0.3, etc.) thus resulting in .1, .2, .3, etc., respectively.

Also, I do not wish to leave "orphaned commas" (e.g., "height":0.1, ,"length":0.3) where width was zero.

Is there a RegEx for this?

Answer 1

If you are using Newtonsoft.Json to serialize the object to json you can use the DefaultValueHandling setting to tell it to ignore properties that do not have a value set.

public class TestSerialize
{
    public int Height { get; set; }

    public int Width { get; set; }
}
class Program
{
    static void Main(string[] args)
    {
        var serializeMe = new TestSerialize() {Height = 12};

        Newtonsoft.Json.JsonSerializerSettings settings = new JsonSerializerSettings();
        settings.DefaultValueHandling = DefaultValueHandling.Ignore;

        string json = Newtonsoft.Json.JsonConvert.SerializeObject(serializeMe, settings);
        Console.WriteLine(json);
    }
}

If you are using System.Text.Json you can use the JsonSerializerOption DefaultIgnoreCondition. Set it to WhenWritingDefault

        System.Text.Json.JsonSerializerOptions options = new JsonSerializerOptions()
            {DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingDefault};

        string json2 = System.Text.Json.JsonSerializer.Serialize(serializeMe, options);
        Console.Write(json2);

Added Javascript serializer example. Add a class to help with serialization. it will exclude nulls or "0"

public class DefaultPropertiesConverter : JavaScriptConverter
{
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
throw new NotImplementedException();
}

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        var jsonExample = new Dictionary<string, object>();
        foreach (var prop in obj.GetType().GetProperties())
        {
            //check if decorated with ScriptIgnore attribute
            bool ignoreProp = prop.IsDefined(typeof(ScriptIgnoreAttribute), true);

            var value = prop.GetValue(obj, BindingFlags.Public, null, null, null);
            if (value != null && value.ToString() != "0" && !ignoreProp)
                jsonExample.Add(prop.Name, value);
        }

        return jsonExample;
    }

    public override IEnumerable<Type> SupportedTypes
    {
        get
        {
            return GetType().Assembly.GetTypes();
        }
    }
}

        var serializer = new JavaScriptSerializer();
        serializer.RegisterConverters(new JavaScriptConverter[] {
            new DefaultPropertiesConverter()
        });

        string json3 = serializer.Serialize(serializeMe);