/// <summary>
/// Parses the $orderby expression.
/// </summary>
/// <param name="orderBy">The $orderby expression string to parse.</param>
/// <returns>The enumeraion of lexical tokens representing order by tokens.</returns>
internal IEnumerable <OrderByToken> ParseOrderBy(string orderBy)
{
Debug.Assert(orderBy != null, "orderBy != null");
this.recursionDepth = 0;
this.lexer = CreateLexerForFilterOrOrderByOrApplyExpression(orderBy);
List <OrderByToken> orderByTokens = new List <OrderByToken>();
while (true)
{
QueryToken expression = this.ParseExpression();
bool ascending = true;
if (this.TokenIdentifierIs(ExpressionConstants.KeywordAscending))
{
this.lexer.NextToken();
}
else if (this.TokenIdentifierIs(ExpressionConstants.KeywordDescending))
{
this.lexer.NextToken();
ascending = false;
}
OrderByToken orderByToken = new OrderByToken(expression, ascending ? OrderByDirection.Ascending : OrderByDirection.Descending);
orderByTokens.Add(orderByToken);
if (this.lexer.CurrentToken.Kind != ExpressionTokenKind.Comma)
{
break;
}
this.lexer.NextToken();
}
this.lexer.ValidateToken(ExpressionTokenKind.End);
return(new ReadOnlyCollection <OrderByToken>(orderByTokens));
}
/// <summary>
/// Visits an OrderByToken
/// </summary>
/// <param name="tokenIn">The OrderByToken to bind</param>
/// <returns>An OrderByClause bound to this OrderByToken</returns>
public virtual T Visit(OrderByToken tokenIn)
{
throw new NotImplementedException();
}
/// <summary>
/// Processes the specified order-by token.
/// </summary>
/// <param name="state">State to use for binding.</param>
/// <param name="thenBy"> The next OrderBy node, or null if there is no orderby after this.</param>
/// <param name="orderByToken">The order-by token to bind.</param>
/// <returns>Returns the combined entityCollection including the ordering.</returns>
private OrderByClause ProcessSingleOrderBy(BindingState state, OrderByClause thenBy, OrderByToken orderByToken)
{
ExceptionUtils.CheckArgumentNotNull(state, "state");
ExceptionUtils.CheckArgumentNotNull(orderByToken, "orderByToken");
QueryNode expressionNode = this.bindMethod(orderByToken.Expression);
// The order-by expressions need to be primitive / enumeration types
SingleValueNode expressionResultNode = expressionNode as SingleValueNode;
if (expressionResultNode == null ||
(expressionResultNode.TypeReference != null &&
!expressionResultNode.TypeReference.IsODataPrimitiveTypeKind() &&
!expressionResultNode.TypeReference.IsODataEnumTypeKind() &&
!expressionResultNode.TypeReference.IsODataTypeDefinitionTypeKind()))
{
throw new ODataException(ODataErrorStrings.MetadataBinder_OrderByExpressionNotSingleValue);
}
OrderByClause orderByNode = new OrderByClause(
thenBy,
expressionResultNode,
orderByToken.Direction,
state.ImplicitRangeVariable);
return(orderByNode);
}
