How to remove trailing zeros of nullable decimal in WebApi IActionResult Ok() function?

Question

I have a sqlSever BDD that store some tables with column like decimal(12,6) and it store values like that ie : 1.000000 for only "1" he adds trailing zero automaticly. And when i take those values with linq and return an IActionResult with Ok(myObjectToSerializeInJson) function from webApi .net core 2.2 It results a json that looks like this :

{
"glu": 43.2,
"suc": 5.6,
"lip": null,
"agSat": 17.4,
"pro": 7.1,
"alc": 0,
"orga": 0,
}

But it was before i decided to upgrade some nuget packages that brings me to latest version of json.net (12.0.1) and now the same request return those trailing zeros...

{
"glu": 43.200000,
"suc": 5.600000,
"lip": null,
"agSat": 17.400000,
"pro": 7.100000,
"alc": 0.000000,
"orga": 0.000000,
}

Is it possible to keep the old behavior ?

Automapper doesn't create JSON so I don't understand your question. — Erik Philips, Aug 08 '19 at 12:22
Besides, trailing zeroes aren't significant. `17.400000` and `17.4` are identical. The zeroes only matter when the decimal gets formatted to string by code that isn't posted in this question. — Panagiotis Kanavos, Aug 08 '19 at 12:24
The same holds for SQL Server- trailing zeroes aren't significant. — Panagiotis Kanavos, Aug 08 '19 at 12:25
I know that trailing zeros aren't signficant but i think that for network performance, it's better to not have those useless caracters in my request. It's heavier. and i have large json with big impact on the size. — Guillaume Réan, Aug 08 '19 at 12:27
Possible duplicate of [How can I force a minimum number of decimal places in Json.net?](https://stackoverflow.com/questions/34568963/how-can-i-force-a-minimum-number-of-decimal-places-in-json-net) — Andrei Dragotoniu, Aug 08 '19 at 12:29
@ErikPhilips you're right, i think this is the webApi controller that convert the autoMapped result object to json. So i think that i need more a .net core configuration or converter for this case ? — Guillaume Réan, Aug 08 '19 at 12:30
@AndreiDragotoniu i've seen that but i don't know how to use it with a IActionResult webApi response like the Ok() function — Guillaume Réan, Aug 08 '19 at 12:31

Guillaume Réan · Answer 1 · 2019-08-09T14:41:30.657

Thanks for your replies guys, it helps me a lot :)

Finally i've added an annotation on each nullable decimal? members of my TDO objects that i thought they were required for my needs. It's look like this :

[JsonConverter(typeof(DecimalJsonConverter))]
public decimal? FielDecimalX { get; set; }

I've wrote a class to handle the conversion like in this solution

    public class DecimalJsonConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(decimal);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue,
            JsonSerializer serializer)
        {
            if (reader.TokenType == JsonToken.Null)
            {
                return null;
            }
            else
            {
                return Convert.ToDecimal(reader.Value, CultureInfo.InvariantCulture);
            }
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            writer.WriteRawValue(((decimal)value).ToString("G6", CultureInfo.InvariantCulture));
        }
    }

I took "G6" for my needs. If a value is greater than 5 decimal the output is x.yE-05 for a decimal value 0.0000xy but javascript reconize correctly this format number.

So output from my API .net core 2.2 returns this json :

{
"eau": 7.83,
"naCl": 0.5,
"orga": 7.2E-05,
"k1": null,
}

Hope that performance are not broken by this change, but i don't see any problems. Thus, i can save payload on my requests. Hope it helps !

How to remove trailing zeros of nullable decimal in WebApi IActionResult Ok() function?

1 Answers1