/// <summary>
/// Scans the specified assembly for classes that implement <see cref="IDIObjectGraphBase{TSource}"/> and
/// registers clr type mappings on the schema between that <see cref="DIObjectGraphType{TDIGraph, TSource}"/>
/// (constructed from that class and its source type), and the source type.
/// Skips classes where the source type is <see cref="object"/>, or where the class is marked with
/// the <see cref="DoNotMapClrTypeAttribute"/>, or where another graph type would be automatically mapped
/// to the specified type, or where a graph type has already been registered to the specified clr type.
/// </summary>
public static IGraphQLBuilder AddDIClrTypeMappings(this IGraphQLBuilder builder, Assembly assembly)
{
var typesAlreadyMapped = new HashSet <Type>(
assembly.GetDefaultClrTypeMappings()
.Where(x => x.GraphType.IsOutputType())
.Select(x => x.ClrType));
var types = assembly.GetTypes()
.Where(x => x.IsClass && !x.IsAbstract && typeof(IDIObjectGraphBase).IsAssignableFrom(x))
.Select <Type, (Type DIGraphType, Type?SourceType)>(x => {
var iface = x.GetInterfaces().FirstOrDefault(x => x.IsGenericType && x.GetGenericTypeDefinition() == typeof(IDIObjectGraphBase <>));
return(x, iface?.GetGenericArguments()[0]);
})
.Where(x => x.SourceType != null && x.SourceType != typeof(object) && !x.DIGraphType.IsDefined(typeof(DoNotMapClrTypeAttribute)) && !typesAlreadyMapped.Contains(x.SourceType))
.Select <(Type DIGraphType, Type?SourceType), (Type ClrType, Type GraphType)>(x => (x.SourceType !, typeof(DIObjectGraphType <,>).MakeGenericType(x.DIGraphType, x.SourceType !)))
.ToList();
if (types.Count == 0)
{
return(builder);
}
builder.ConfigureSchema(schema => {
var existingMappings = new HashSet <Type>(schema.TypeMappings.Where(x => x.graphType.IsOutputType()).Select(x => x.clrType));
foreach (var type in types)
{
if (!existingMappings.Contains(type.ClrType))
{
schema.RegisterTypeMapping(type.ClrType, type.GraphType);
}
}
});
return(builder);
}