public DocumentDesigner <TEntity> With <TMember, TReturn>(string name, Expression <Func <TEntity, TMember> > projector, Func <TMember, TReturn> converter, params Option[] options)
{
if (typeof(TReturn) == typeof(string))
{
options = options.Concat(new MaxLength(850)).ToArray();
}
var column = design.Table[name];
if (DocumentTable.IdColumn.Equals(column))
{
throw new ArgumentException("You can not make a projection for IdColumn. Use Document.Key() method instead.");
}
if (column == null)
{
var lengthOption = options
.OfType <MaxLength>()
.FirstOrDefault();
column = design.Table.Add(new Column <TReturn>(name, lengthOption?.Length));
}
Func <object, object> compiledProjector;
if (!options.OfType <DisableNullCheckInjection>().Any())
{
var nullCheckInjector = new NullCheckInjector();
var nullCheckedProjector = (Expression <Func <TEntity, object> >)nullCheckInjector.Visit(projector);
if (!nullCheckInjector.CanBeTrustedToNeverReturnNull && !column.IsPrimaryKey)
{
column.Nullable = true;
}
compiledProjector = Compile(name, nullCheckedProjector);
}
else
{
compiledProjector = Compile(name, projector);
}
var newProjection = Projection.From <TReturn>(document =>
{
var value = compiledProjector(document);
if (value == null)
{
return(null);
}
return(converter((TMember)value));
});
if (!newProjection.ReturnType.IsCastableTo(column.Type))
{
throw new InvalidOperationException(
$"Can not override projection for {name} of type {column.Type} " +
$"with a projection that returns {newProjection.ReturnType} (on {typeof (TEntity)}).");
}
Projection existingProjection;
if (!design.Projections.TryGetValue(name, out existingProjection))
{
if (design.Parent != null && !column.IsPrimaryKey)
{
column.Nullable = true;
}
design.Projections.Add(column, newProjection);
}
else
{
design.Projections[name] = newProjection;
}
return(this);
}