private void BuildJoiner <TCompatibleRequest>(CrudRequestConfig <TCompatibleRequest> config)
{
if (EntityKey == null || RequestItemKey == null)
{
return;
}
var joinInfo = typeof(EnumerableExtensions)
.GetMethod("FullOuterJoin", BindingFlags.Static | BindingFlags.NonPublic)
.MakeGenericMethod(typeof(object), typeof(TEntity), RequestItemKey.KeyType);
var makeKeySelectorInfo = typeof(CrudBulkRequestEntityConfigBuilder <TRequest, TItem, TEntity>)
.GetMethod("MakeKeySelector", BindingFlags.Static | BindingFlags.NonPublic);
var itemsParam = Expression.Parameter(typeof(IEnumerable <object>));
var entitiesParam = Expression.Parameter(typeof(IEnumerable <TEntity>));
var makeLeftKeySelector = makeKeySelectorInfo.MakeGenericMethod(typeof(object), RequestItemKey.KeyType);
var convLeftKeyParam = Expression.Parameter(typeof(object));
var convLeftKeyCall = Expression.Invoke(
RequestItemKey.KeyExpression,
Expression.Convert(convLeftKeyParam, typeof(TItem)));
var leftKeyExpr = Expression.Call(makeLeftKeySelector, Expression.Lambda(convLeftKeyCall, convLeftKeyParam));
var makeRightKeySelector = makeKeySelectorInfo.MakeGenericMethod(typeof(TEntity), EntityKey.KeyType);
var rightKeyExpr = Expression.Call(makeRightKeySelector, Expression.Constant(EntityKey.KeyExpression));
var joinExpr = Expression.Call(joinInfo, itemsParam, entitiesParam, leftKeyExpr, rightKeyExpr);
var lambdaExpr = Expression.Lambda <Func <IEnumerable <object>, IEnumerable <TEntity>, IEnumerable <Tuple <object, TEntity> > > >(
joinExpr, itemsParam, entitiesParam);
config.SetEntityJoiner(lambdaExpr.Compile());
}
