/// <summary>
/// Translates an OData $orderby represented by <see cref="OrderByClause"/> to <see cref="Expression"/> and apply to <see cref="IQueryable" />.
/// </summary>
/// <param name="binder">The given filter binder.</param>
/// <param name="query">The given source.</param>
/// <param name="orderByClause">The filter clause.</param>
/// <param name="context">The query binder context.</param>
/// <param name="alreadyOrdered">The boolean value indicating whether it's ordered or not.</param>
/// <returns>The applied result.</returns>
public static IQueryable ApplyBind(this IOrderByBinder binder, IQueryable query, OrderByClause orderByClause, QueryBinderContext context, bool alreadyOrdered)
{
if (binder == null)
{
throw Error.ArgumentNull(nameof(binder));
}
if (query == null)
{
throw Error.ArgumentNull(nameof(query));
}
if (orderByClause == null)
{
throw Error.ArgumentNull(nameof(orderByClause));
}
if (context == null)
{
throw Error.ArgumentNull(nameof(context));
}
OrderByBinderResult orderByResult = binder.BindOrderBy(orderByClause, context);
IQueryable querySoFar = query;
Type elementType = context.ElementClrType;
OrderByBinderResult result = orderByResult;
do
{
LambdaExpression orderByExpression = result.OrderByExpression as LambdaExpression;
Contract.Assert(orderByExpression != null);
OrderByDirection direction = result.Direction;
querySoFar = ExpressionHelpers.OrderBy(querySoFar, orderByExpression, direction, elementType, alreadyOrdered);
alreadyOrdered = true;
result = result.ThenBy;
}while (result != null);
return(querySoFar);
}
/// <summary>
/// Translates an OData $orderby represented by <see cref="OrderByClause"/> to <see cref="Expression"/>.
/// $orderby=Age
/// |-- x => x.Age
/// </summary>
/// <param name="orderByClause">The orderby clause.</param>
/// <param name="context">The query binder context.</param>
/// <returns>The OrderBy binder result, <see cref="OrderByBinderResult"/>.</returns>
public virtual OrderByBinderResult BindOrderBy(OrderByClause orderByClause, QueryBinderContext context)
{
if (orderByClause == null)
{
throw Error.ArgumentNull(nameof(orderByClause));
}
if (context == null)
{
throw Error.ArgumentNull(nameof(context));
}
OrderByBinderResult head = null;
OrderByBinderResult last = null;
for (OrderByClause clause = orderByClause; clause != null; clause = clause.ThenBy)
{
Expression body = Bind(clause.Expression, context);
ParameterExpression parameter = context.CurrentParameter;
LambdaExpression orderByLambda = Expression.Lambda(body, parameter);
OrderByBinderResult result = new OrderByBinderResult(orderByLambda, clause.Direction);
if (head == null)
{
head = result;
last = result;
}
else
{
Contract.Assert(last != null);
last.ThenBy = result;
last = result;
}
}
return(head);
}
