context.GetArgument() returning null with ByteGraphType - entity-framework

Question

I´m learning how to use CustomScalar in graphql-dotnet.
I have a tinyint column in my table and from what I have read, I´m supposed to use byte on this column in C#. After research I found out that I need to create a ByteGraphType, but I´m having trouble doing that.
I got the ByteGraphType example from this link https://github.com/graphql-dotnet/graphql-dotnet/issues/458, so I think it will work.
With this code, I can query the table, however, my mutation is not working. I didn´t find an example to demonstrate how the mutation would look like with a byte column. I tried as is stated in my code example, but in this line (var avaliacao = context.GetArgument("avaliacao");), my argument avaliacao.Nota is returning null and I´m not sure on how to proceed.
Can someone help me?
Thank you
THAT´S MY CODE
//Model
[Column("nota")]
public byte Nota { get; set; }
//Type
Field<ByteGraphType>("Nota", resolve: context => context.Source.Nota);
//InputType
Field<ByteGraphType>("nota");
//Query
Field<ListGraphType<AvaliacaoType>>(
"avaliacoes",
resolve: context => contextServiceLocator.AvaliacaoRepository.All());
//Mutation
Field<AvaliacaoType>(
"createAvaliacao",
arguments: new QueryArguments(
new QueryArgument<NonNullGraphType<AvaliacaoInputType>> { Name = "avaliacao" }
),
resolve: context =>
{
var schema = new Schema();
schema.RegisterValueConverter(new ByteValueConverter());
var avaliacao = context.GetArgument<Avaliacao>("avaliacao");
avaliacao.Nota.AstFromValue(schema, new ByteGraphType());
return contextServiceLocator.AvaliacaoRepository.Add(avaliacao);
});
//ByteGraphType
using GraphQL.Language.AST;
using GraphQL.Types;
using System;
namespace Api.Helpers
{
public class ByteGraphType : ScalarGraphType
{
public ByteGraphType()
{
Name = "Byte";
}
public override object ParseLiteral(IValue value)
{
var byteVal = value as ByteValue;
return byteVal?.Value;
}
public override object ParseValue(object value)
{
if (value == null)
return null;
try
{
var result = Convert.ToByte(value);
return result;
}
catch (FormatException)
{
return null;
}
}
public override object Serialize(object value)
{
return ParseValue(value).ToString();
}
public class ByteValueConverter : IAstFromValueConverter
{
public bool Matches(object value, IGraphType type)
{
return value is byte;
}
public IValue Convert(object value, IGraphType type)
{
return new ByteValue((byte)value);
}
}
public class ByteValue : ValueNode<byte>
{
public ByteValue(byte value)
{
Value = value;
}
protected override bool Equals(ValueNode<byte> node)
{
return Value == node.Value;
}
}
}
}
What I need is to be able to save a record of a table that has a tinyint column. If I change the type in my code to int, I can mutate, but can´t query.

Answer 1

I changed my CustomScalar and it worked:
using GraphQL.Language.AST;
using GraphQL.Types;
using System;
namespace Api.Helpers
{
public class ByteGraphType : ScalarGraphType
{
public ByteGraphType()
{
Name = "Byte";
Description = "ByteGraphType";
}
/// <inheritdoc />
public override object Serialize(object value)
{
return ParseValue(value).ToString();
}
/// <inheritdoc />
public override object ParseValue(object value)
{
byte result;
if (byte.TryParse(value?.ToString() ?? string.Empty, out result))
{
return result;
}
return null;
}
/// <inheritdoc />
public override object ParseLiteral(IValue value)
{
if (value is StringValue)
{
return ParseValue(((StringValue)value).Value);
}
return null;
}
}
}