private void TranslateOrderBy(OrderByExpression node)
{
Translate(node.Source);
BsonDocument sort = new BsonDocument();
foreach (var clause in node.Clauses)
{
var field = FieldExpressionFlattener.FlattenFields(clause.Expression) as IFieldExpression;
if (field == null)
{
throw new NotSupportedException("Only fields are allowed in a $sort.");
}
var direction = clause.Direction == SortDirection.Ascending ? 1 : -1;
if (sort.Contains(field.FieldName))
{
var message = string.Format("Redundant ordering fields are not supported: {0}.", field.FieldName);
throw new NotSupportedException(message);
}
sort.Add(field.FieldName, direction);
}
_stages.Add(new BsonDocument("$sort", sort));
}
public static RenderedProjectionDefinition <TProjection> Translate <TDocument, TProjection>(Expression <Func <TDocument, TProjection> > projector, IBsonSerializer <TDocument> parameterSerializer, IBsonSerializerRegistry serializerRegistry)
{
var bindingContext = new PipelineBindingContext(serializerRegistry);
var documentExpression = new DocumentExpression(parameterSerializer);
bindingContext.AddExpressionMapping(projector.Parameters[0], documentExpression);
var node = PartialEvaluator.Evaluate(projector.Body);
node = Transformer.Transform(node);
node = bindingContext.Bind(node, isClientSideProjection: true);
node = FieldExpressionFlattener.FlattenFields(node);
BsonDocument projectionDocument = null;
IBsonSerializer <TProjection> serializer;
if (node is DocumentExpression)
{
serializer = new ProjectingDeserializer <TDocument, TProjection>(parameterSerializer, projector.Compile());
}
else
{
var candidateFields = SerializationExpressionGatherer.Gather(node);
var fields = GetUniqueFieldsByHierarchy(candidateFields);
var serializationInfo = fields.Select(x => new BsonSerializationInfo(x.FieldName, x.Serializer, x.Serializer.ValueType)).ToList();
var projectedObjectExpression = Expression.Parameter(typeof(ProjectedObject), "document");
var translator = new FindProjectionTranslator(documentExpression, projectedObjectExpression, fields);
var translated = translator.Visit(node);
if (translator._fullDocument)
{
serializer = new ProjectingDeserializer <TDocument, TProjection>(parameterSerializer, projector.Compile());
}
else
{
var newProjector = Expression.Lambda <Func <ProjectedObject, TProjection> >(
translated,
projectedObjectExpression);
projectionDocument = GetProjectionDocument(serializationInfo);
var projectedObjectSerializer = new ProjectedObjectDeserializer(serializationInfo);
serializer = new ProjectingDeserializer <ProjectedObject, TProjection>(projectedObjectSerializer, newProjector.Compile());
}
}
return(new RenderedProjectionDefinition <TProjection>(projectionDocument, serializer));
}