protected ProcessingResult GetKeys(LambdaExpression keySelector, ProcessingResult parentResult, DataContext context)
{
if (!parentResult.IsDeferred())
{
var keys = (IList)Activator.CreateInstance(typeof(List <>).MakeGenericType(keySelector.ReturnType));
var compiledSelector = CompiledExpressionStorage.GetOrAddCompiledLambda(keySelector);
foreach (var item in parentResult.GetItems())
{
keys.Add(compiledSelector.DynamicInvoke(item));
}
return(new ProcessingResult(true, keys));
}
var nodeReferences = parentResult.GetDeferredList();
var keysResult = ExpressionProcessingHelper.ProcessExpression(keySelector.Body, nodeReferences, context);
if (!keysResult.IsSuccess)
{
return(ProcessingResult.Unsuccessful);
}
if (keysResult.IsSingleItem)
{
keysResult = ExpressionProcessingHelper.CopyInstances(keysResult, nodeReferences.Count,
() => ExpressionProcessingHelper.ProcessExpression(keySelector.Body, nodeReferences, context).Result);
}
keysResult = new ProcessingResult(true, keysResult.GetLoadedItems(keySelector.ReturnType));
return(QueryProcessingHelper.NormalizeMultipleResult(keysResult, keySelector.ReturnType));
}
public ProcessingResult ProcessQuery(MethodCallExpression query, ProcessingResult parentResult, DataContext context)
{
if (!parentResult.IsDeferred())
{
return(ProcessingResult.Unsuccessful);
}
var unaryExpression = (UnaryExpression)query.Arguments[1];
var lambdaExpression = (LambdaExpression)unaryExpression.Operand;
if (lambdaExpression.Parameters.Count > 1)
{
return(ProcessingResult.Unsuccessful);
}
var memberExpression = lambdaExpression.Body;
var nodeReferences = parentResult.GetDeferredList();
var result = ExpressionProcessingHelper.ProcessExpression(memberExpression, nodeReferences, context);
if (!result.IsSuccess)
{
return(ProcessingResult.Unsuccessful);
}
var targetItemType = QueryProcessingHelper.GetReturnParameterType(query);
if (!result.IsSingleItem)
{
return(QueryProcessingHelper.NormalizeMultipleResult(result, targetItemType));
}
var multipleResult = ExpressionProcessingHelper.CopyInstances(result, nodeReferences.Count,
() => ExpressionProcessingHelper.ProcessExpression(memberExpression, nodeReferences, context).Result);
return(new ProcessingResult(true, QueryProcessingHelper.NormalizeMultipleResult(multipleResult, targetItemType).Result));
}
public ProcessingResult ProcessQuery(MethodCallExpression query, ProcessingResult parentResult, DataContext context)
{
if (!parentResult.IsDeferred())
{
return(ProcessingResult.Unsuccessful);
}
var hasSelector = query.Arguments.Count > 1;
var elementType = QueryProcessingHelper.GetReturnParameterType(query);
if (!hasSelector)
{
var items = parentResult.GetLoadedItems(elementType);
return(new ProcessingResult(true, ProcessQuery(items), true));
}
var unaryExpression = (UnaryExpression)query.Arguments[1];
var selectorLambda = (LambdaExpression)unaryExpression.Operand;
var selectorResult = ExpressionProcessingHelper.ProcessExpression(selectorLambda.Body, parentResult.GetDeferredList(), context);
if (!selectorResult.IsSuccess)
{
return(ProcessingResult.Unsuccessful);
}
if (selectorResult.IsSingleItem)
{
var result = Convert.ChangeType(selectorResult.Result, elementType);
return(new ProcessingResult(true, result, true));
}
var loadedItems = selectorResult.GetLoadedItems(elementType);
return(new ProcessingResult(true, ProcessQuery(loadedItems), true));
}
