Field Arguments

Some GraphQL fields require arguments. For instance, if you have a query like this:

{
    thing(id: 224) {
        name
        location
        price
    }
}

that id is an argument. OttoTheGeek models field arguments using an args type. An instance of your args type is passed to the resolver when resolving the field.

Representing the schema that would satisfy the above query might look something like this:

public sealed class Query
{
    public Thing Thing { get; set; }
}

public sealed class Thing
{
    public string Name { get; set; }
    public string Location { get; set; }
    public decimal Price { get; set; }
}

public sealed class ThingArgs
{
    public int Id { get; set; }
}

public sealed class Model : OttoModel<Query>
{
    protected override SchemaBuilder ConfigureSchema(SchemaBuilder builder)
    {
        return builder.QueryField(x => x.Thing)
            .WithArgs<ThingArgs>()
            .ResolvesVia<Resolver>();
    }
}

public sealed class Resolver : IScalarFieldWithArgsResolver<Child, ThingArgs>
{
    public Task<Child> Resolve(ThingArgs args)
    {
        return Task.FromResult(new Thing {
            Name = $"Thing {args.Id}",
            Location = "Stockroom",
            Price = 200m
        });
    }
}

Note: The args type itself doesn’t get represented in the GraphQL schema, but its fields do.