internal override RenderedProjectionDefinition <TOutput> TranslateExpressionToProjection <TInput, TOutput>(
Expression <Func <TInput, TOutput> > expression,
IBsonSerializer <TInput> inputSerializer,
IBsonSerializerRegistry serializerRegistry,
ExpressionTranslationOptions translationOptions)
{
return(AggregateProjectTranslator.Translate <TInput, TOutput>(expression, inputSerializer, serializerRegistry, translationOptions));
}
private async Task <ProjectedResult <TResult> > Project <TResult>(Expression <Func <Root, TResult> > projector)
{
var serializer = BsonSerializer.SerializerRegistry.GetSerializer <Root>();
var projectionInfo = AggregateProjectTranslator.Translate(projector, serializer, BsonSerializer.SerializerRegistry);
var pipelineOperator = new BsonDocument("$project", projectionInfo.Document);
var result = await _collection.Aggregate()
.Project(new BsonDocumentProjectionDefinition <Root, TResult>(projectionInfo.Document, projectionInfo.ProjectionSerializer))
.FirstAsync();
return(new ProjectedResult <TResult>
{
Projection = projectionInfo.Document,
Value = result
});
}
private async Task <ProjectedResult <TResult> > Project <TResult>(Expression <Func <Root, TResult> > projector)
{
var serializer = BsonSerializer.SerializerRegistry.GetSerializer <Root>();
var projectionInfo = AggregateProjectTranslator.Translate(projector, serializer, BsonSerializer.SerializerRegistry);
var pipelineOperator = new BsonDocument("$project", projectionInfo.Document);
using (var cursor = await _collection.AggregateAsync(new PipelineStagePipelineDefinition <Root, TResult>(new PipelineStageDefinition <Root, TResult>[] { pipelineOperator }, projectionInfo.ProjectionSerializer)))
{
var list = await cursor.ToListAsync();
return(new ProjectedResult <TResult>
{
Projection = projectionInfo.Document,
Value = (TResult)list[0]
});
}
}
public override RenderedProjectionDefinition <TNewResult> Render(IBsonSerializer <TResult> documentSerializer, IBsonSerializerRegistry serializerRegistry)
{
return(AggregateProjectTranslator.Translate <TResult, TNewResult>(_expression, documentSerializer, serializerRegistry, _translationOptions));
}
