/// <summary>Filters a query like a SQL WHERE clause does.</summary>
/// <param name="service">Service with data and configuration.</param>
/// <param name="requestDescription">RequestDescription instance containing information about the current request being parsed.</param>
/// <param name="source">Original source for query expression.</param>
/// <returns>The composed query expression.</returns>
internal static Expression Where(IDataService service, RequestDescription requestDescription, Expression source)
{
Debug.Assert(service != null, "service != null");
Debug.Assert(source != null, "source != null");
Debug.Assert(requestDescription != null, "requestDescription != null");
FilterClause filterClause = new RequestExpressionParser(service, requestDescription).ParseFilter();
if (filterClause == null)
{
return(source);
}
bool filterQueryApplicable = requestDescription.TargetKind == RequestTargetKind.Resource ||
requestDescription.TargetKind == RequestTargetKind.OpenProperty ||
requestDescription.TargetKind == RequestTargetKind.ComplexObject ||
requestDescription.CountOption == RequestQueryCountOption.CountSegment;
if (!filterQueryApplicable)
{
throw DataServiceException.CreateBadRequestError(Strings.RequestQueryProcessor_QueryFilterOptionNotApplicable);
}
Type queryElementType = source.ElementType();
Debug.Assert(queryElementType != null, "queryElementType != null");
ParameterExpression parameterForIt = Expression.Parameter(queryElementType, "it");
Debug.Assert(
(requestDescription.TargetResourceSet == null && (requestDescription.TargetResourceType == null || requestDescription.TargetResourceType.ResourceTypeKind != ResourceTypeKind.EntityType)) ||
(requestDescription.TargetResourceType != null && requestDescription.TargetResourceType.ResourceTypeKind == ResourceTypeKind.EntityType),
"setForIt cannot be null if typeForIt is an entity type.");
Debug.Assert(
requestDescription.TargetResourceType == null && parameterForIt.Type == typeof(object) ||
requestDescription.TargetResourceType != null && requestDescription.TargetResourceType.InstanceType == parameterForIt.Type,
"non-open type expressions should have a typeForIt");
var translator = NodeToExpressionTranslator.Create(service, requestDescription, parameterForIt);
LambdaExpression lambda = translator.TranslateFilterClause(filterClause);
return(source.QueryableWhere(lambda));
}
/// <summary>Filters a query like a SQL WHERE clause does.</summary>
/// <param name="service">Service with data and configuration.</param>
/// <param name="requestDescription">RequestDescription instance containing information about the current request being parsed.</param>
/// <param name="source">Original source for query expression.</param>
/// <returns>The composed query expression.</returns>
internal static Expression Where(IDataService service, RequestDescription requestDescription, Expression source)
{
Debug.Assert(service != null, "service != null");
Debug.Assert(source != null, "source != null");
Debug.Assert(requestDescription != null, "requestDescription != null");
FilterClause filterClause = new RequestExpressionParser(service, requestDescription).ParseFilter();
if (filterClause == null)
{
return source;
}
bool filterQueryApplicable = requestDescription.TargetKind == RequestTargetKind.Resource
|| requestDescription.TargetKind == RequestTargetKind.OpenProperty
|| requestDescription.TargetKind == RequestTargetKind.ComplexObject
|| requestDescription.CountOption == RequestQueryCountOption.CountSegment;
if (!filterQueryApplicable)
{
throw DataServiceException.CreateBadRequestError(Strings.RequestQueryProcessor_QueryFilterOptionNotApplicable);
}
Type queryElementType = source.ElementType();
Debug.Assert(queryElementType != null, "queryElementType != null");
ParameterExpression parameterForIt = Expression.Parameter(queryElementType, "it");
Debug.Assert(
(requestDescription.TargetResourceSet == null && (requestDescription.TargetResourceType == null || requestDescription.TargetResourceType.ResourceTypeKind != ResourceTypeKind.EntityType)) ||
(requestDescription.TargetResourceType != null && requestDescription.TargetResourceType.ResourceTypeKind == ResourceTypeKind.EntityType),
"setForIt cannot be null if typeForIt is an entity type.");
Debug.Assert(
requestDescription.TargetResourceType == null && parameterForIt.Type == typeof(object) ||
requestDescription.TargetResourceType != null && requestDescription.TargetResourceType.InstanceType == parameterForIt.Type,
"non-open type expressions should have a typeForIt");
var translator = NodeToExpressionTranslator.Create(service, requestDescription, parameterForIt);
LambdaExpression lambda = translator.TranslateFilterClause(filterClause);
return source.QueryableWhere(lambda);
}
/// <summary>
/// Builds the collection of ordering expressions including implicit ordering if paging is required at top level
/// </summary>
private void ObtainOrderingExpressions()
{
const String Comma = ",";
const char Space = ' ';
const String AscendingOrderIdentifier = "asc";
const string QuestionMark = "?";
const string EqualMark = "=";
const string AndMark = "&";
if (!string.IsNullOrEmpty(this.service.OperationContext.RequestMessage.GetQueryStringItem(XmlConstants.HttpQueryStringOrderBy)))
{
this.CheckSetQueryApplicable();
}
Debug.Assert(this.topLevelOrderingInfo == null, "Must only be called once per query");
ResourceType rt = this.description.TargetResourceType;
this.topLevelOrderingInfo = new OrderingInfo(this.IsStandardPaged);
OrderByClause orderByClause = new RequestExpressionParser(this.service, this.description).ParseOrderBy();
// We need to generate ordering expression(when we don't have top level $orderby), if either the result is paged, or we have
// skip or top count request because in that case, the skip or top has to happen in
// the expand provider.
if (orderByClause == null)
{
if (this.IsStandardPaged || this.topCount.HasValue || this.skipCount.HasValue)
{
Uri requestUri = this.service.OperationContext.AbsoluteRequestUri;
StringBuilder orderBy = string.IsNullOrEmpty(requestUri.Query) ? new StringBuilder(requestUri.AbsoluteUri + QuestionMark) : new StringBuilder(requestUri.AbsoluteUri + AndMark);
orderBy.Append(XmlConstants.HttpQueryStringOrderBy + EqualMark);
String separator = String.Empty;
foreach (var keyProp in this.description.TargetResourceSet.GetKeyPropertiesForOrderBy())
{
orderBy.Append(separator).Append(keyProp.Name).Append(Space).Append(AscendingOrderIdentifier);
separator = Comma;
}
var uriParser = RequestUriProcessor.CreateUriParserWithBatchReferenceCallback(this.service, new Uri(orderBy.ToString()));
orderByClause = uriParser.ParseOrderBy();
}
else
{
return;
}
}
ParameterExpression elementParameter = Expression.Parameter(rt.InstanceType, "element");
var translator = NodeToExpressionTranslator.Create(this.service, this.description, elementParameter);
IEnumerable<OrderingExpression> ordering = translator.TranslateOrderBy(orderByClause);
this.topLevelOrderingInfo.AddRange(ordering);
if (this.IsStandardPaged)
{
this.description.SkipTokenExpressionCount = this.topLevelOrderingInfo.OrderingExpressions.Count;
this.description.SkipTokenProperties = NeedSkipTokenVisitor.CollectSkipTokenProperties(this.topLevelOrderingInfo, rt);
}
}