Custom type mapping

[manoack]

I try to implement a custom mapping. For some fields I try to map Edm.Decimal to System.String using a custom conversion attribute. I don't find an approach. Is it possible?

Additional detail

In my server code I want to deal with string fields (native database content). From WebApi I try to deal with decimal values. But approaches with JsonConvert attributes fail (no effect).

[xuzhg]

@manoack Is https://github.com/OData/odata.net/blob/master/src/Microsoft.OData.Core/ODataPayloadValueConverter.cs what you are looking for?

[manoack]

@manoack Is https://github.com/OData/odata.net/blob/master/src/Microsoft.OData.Core/ODataPayloadValueConverter.cs what you are looking for?

I'm not sure, I find no way to inject it. I try to extend the ODataRoutingExample:

.AddRouteComponents("", model0, action => { action.AddSingleton(typeof(ODataPayloadValueConverter), new MyConverter()); })
But code in my converter is not called. I see similar problem here:
OData/AspNetCoreOData#732

I suppose, AddRouteComponents add a default implementation of ODataPayloadValueConverter with more priority and I can't change this behaviour.

Is there any example to implement such custom converter correctly?

[desirade-fm]

I have the same problem.

[gathogojr]

@manoack It's not clear to me whether what you want to do is to format decimals stored in the database as strings or to format decimals to strings. Either way the custom ODataPayloadValueConverter should work.
Please note that this converter is used during serialization, not deserialization.
Here's how you'd go about implementing the custom converter:

public class MyConverter : ODataPayloadValueConverter
{
    public override object ConvertToPayloadValue(object value, IEdmTypeReference edmTypeReference)
    {
        if (edmTypeReference.PrimitiveKind() == EdmPrimitiveTypeKind.Decimal)
        {
            var decimalValue = (decimal)value;
            return decimal.ToString("#.##");
        }

        return base.ConvertToPayloadValue(value, edmTypeReference);
    }
}

The custom converter can be injected in the dependency injection container as follows:

services.AddControllers().AddOData(
    options => options.AddRouteComponents(
        routePrefix: string.Empty,
        model: model0,
        configureServices: sp => sp.AddSingleton(
            serviceType: typeof(ODataPayloadValueConverter),
            implementationInstance: new MyConverter())));

There's nothing like this:

AddRouteComponents add a default implementation of ODataPayloadValueConverter with more priority and I can't change this behaviour

This is the way to do it using a custom converter. You can refer to a similar issue here with a similar proposal/solution.