HC custom filter WIP

hc-custom-filter.cs

public class EntityIdOperationFilterInputType : FilterInputType
{
    protected override void Configure(IFilterInputTypeDescriptor descriptor)
    {
        descriptor
            .Operation(DefaultFilterOperations.Equals)
            .Type<LongType>();
    }
}

public abstract class QueryableEntityIdOperationHandler : QueryableOperationHandlerBase
{
    protected QueryableEntityIdOperationHandler(InputParser inputParser) : base(inputParser) { }

    protected abstract int Operation { get; }

    public override bool CanHandle(
        ITypeCompletionContext context,
        IFilterInputTypeDefinition typeDefinition,
        IFilterFieldDefinition fieldDefinition)
    {
        return context.Type is EntityIdOperationFilterInputType &&
            fieldDefinition is FilterOperationFieldDefinition operationField &&
            operationField.Id == this.Operation;
    }
}

public class QueryableEntityIdEqualsHandler : QueryableEntityIdOperationHandler
{
    public QueryableEntityIdEqualsHandler(InputParser inputParser) : base(inputParser) { }

    protected override int Operation => DefaultFilterOperations.Equals;

    public override Expression HandleOperation(
        QueryableFilterContext context,
        IFilterOperationField field,
        IValueNode value,
        object? parsedValue)
    {
        Console.WriteLine("Not getting here yet, so not implemented.");

        var property = context.GetInstance();
        return FilterExpressionBuilder.Equals(property, parsedValue);
    }
}

// Usage.

public class ArticleFilterType : FilterInputType<Article>
{
    protected override void Configure(IFilterInputTypeDescriptor<Article> descriptor)
    {
        descriptor.BindFieldsExplicitly();

        descriptor.Field("entityId").Type<EntityIdOperationFilterInputType>();
    }
}

// Registration.

.AddConvention<IFilterConvention>(
    new FilterConventionExtension(
        x => x.AddProviderExtension(
            new QueryableFilterProviderExtension(
                y => y.AddFieldHandler<QueryableEntityIdEqualsHandler>()))