Serializing .net class with decimal (5,2)

[jeromesubs]

Hello,

I just started to use the Chr.Avro library

The default schemabuilder seems to always use precision (29, 14) and scale for Avro decimal logical type

When I create the schema for my .Net class, I would like to be able to specify that all decimal should be with precision and scale (5,2).

How could I do that?

[dstelljes]

To override that default, you can create a custom schema builder case that sets a custom precision and scale:

using System;
using Chr.Avro.Abstract;

public class CustomDecimalSchemaBuilderCase : SchemaBuilderCase, ISchemaBuilderCase
{
    public virtual SchemaBuilderCaseResult BuildSchema(Type type, SchemaBuilderContext context)
    {
        if (type == typeof(decimal))
        {
            var decimalSchema = new BytesSchema
            {
                LogicalType = new DecimalLogicalType(5, 2),
            };

            try
            {
                context.Schemas.Add(type, decimalSchema);
            }
            catch (ArgumentException exception)
            {
                throw new InvalidOperationException($"A schema for {type} already exists on the schema builder context.", exception);
            }

            return SchemaBuilderCaseResult.FromSchema(decimalSchema);
        }
        else
        {
            return SchemaBuilderCaseResult.FromException(new UnsupportedTypeException(type, $"{nameof(CustomDecimalSchemaBuilderCase)} can only be applied to the {typeof(decimal)} type."));
        }
    }
}

and then create a custom schema builder that uses it:

var schemaBuilder = new SchemaBuilder(
    SchemaBuilder.CreateDefaultCaseBuilders()
        .Prepend(builder => new CustomDecimalSchemaBuilderCase(builder)));

var schema = schemaBuilder.BuildSchema<decimal>();

[jeromesubs]

thanks a lot !!
It seems to work :)

I have another question though ... how to ensure that the order in the json schema matches the order of my .net object/class?
In the tests I have performed, the order is wrong despite using the DataContract annotations.

[dstelljes]

Are you using the latest version of the library (8.1.1)? We recently pushed some fixes to [DataMember] handling.

[jeromesubs]

No I was still on 8.0.2
I'll try that version and let you know if there is still an issue

[jeromesubs]

I confirm that the member order works with 8.1.1 :)

Thanks!

[dstelljes]

As of 9.0.0, you can use the [Range] attribute to override decimal precision and scale for a field or property. See the release notes for details.

For earlier versions, or to change the default precision and scale for all generated decimal schemas, see this previous answer.