public IQueryable Sort()
{
IQueryable query = queryable;
bool isFirst = true;
foreach (var descriptor in this.sortDescriptors)
{
Type memberType = typeof(object);
var descriptorBuilder = ExpressionBuilderFactory.MemberAccess(queryable, memberType, descriptor.Member);
var expression = descriptorBuilder.CreateLambdaExpression();
string methodName = "";
if (isFirst)
{
methodName = descriptor.SortDirection == ListSortDirection.Ascending ?
"OrderBy" : "OrderByDescending";
isFirst = false;
}
else
{
methodName = descriptor.SortDirection == ListSortDirection.Ascending ?
"ThenBy" : "ThenByDescending";
}
query = query.Provider.CreateQuery(
Expression.Call(
typeof(Queryable),
methodName,
new[] { query.ElementType, expression.Body.Type },
query.Expression,
Expression.Quote(expression)));
}
return(query);
}
public static MemberAccessExpressionBuilderBase MemberAccess(Expression expression, Type memberType, string memberName)
{
var builder = ExpressionBuilderFactory.MemberAccess(expression.GetUnderlyingElementType(), memberType, memberName);
//builder.Options.LiftMemberAccessToNull = source.Provider.IsLinqToObjectsProvider();
builder.Options.LiftMemberAccessToNull = false;
return(builder);
}
private LambdaExpression CreateMemberSelectorExpression()
{
var memberAccessBuilder = ExpressionBuilderFactory.MemberAccess(this.ItemType, null, this.Function.SourceField);
memberAccessBuilder.Options.CopyFrom(this.Options);
var memberExpression = memberAccessBuilder.CreateMemberAccessExpression();
memberExpression = ConvertMemberAccessExpression(memberExpression);
return(Expression.Lambda(memberExpression, memberAccessBuilder.ParameterExpression));
}
internal static IQueryable SelectDistinct(this IQueryable source, Type propertyType, string propertyName)
{
var builder = ExpressionBuilderFactory.MemberAccess(source, propertyType, propertyName);
LambdaExpression lambda = builder.CreateLambdaExpression();
var queryable = source.Select(lambda);
queryable = queryable.Provider.CreateQuery(
Expression.Call(
typeof(Queryable),
"Distinct",
new[] { lambda.Body.Type },
queryable.Expression));
return(queryable);
}
protected virtual Expression CreateMemberExpression()
{
Type memberType = FilterDescriptor.MemberType;
MemberAccessExpressionBuilderBase expressionBuilderBase =
ExpressionBuilderFactory.MemberAccess(ParameterExpression.Type, memberType, FilterDescriptor.Member);
expressionBuilderBase.Options.CopyFrom(Options);
expressionBuilderBase.ParameterExpression = ParameterExpression;
Expression expression = expressionBuilderBase.CreateMemberAccessExpression();
if (memberType != null &&
TypeExtensions.GetNonNullableType(expression.Type) != TypeExtensions.GetNonNullableType(memberType))
{
expression = Expression.Convert(expression, memberType);
}
return(expression);
}
protected virtual Expression CreateMemberExpression()
{
var memberType = this.FilterDescriptor.MemberType;
var memberAccessBuilder =
ExpressionBuilderFactory.MemberAccess(this.ParameterExpression.Type, memberType, this.FilterDescriptor.Member);
memberAccessBuilder.Options.CopyFrom(this.Options);
memberAccessBuilder.ParameterExpression = this.ParameterExpression;
Expression memberAccessExpression = memberAccessBuilder.CreateMemberAccessExpression();
if (memberType != null && memberAccessExpression.Type.GetNonNullableType() != memberType.GetNonNullableType())
{
memberAccessExpression = Expression.Convert(memberAccessExpression, memberType);
}
return(memberAccessExpression);
}
public static LambdaExpression Lambda <T>(string memberName, bool checkForNull)
{
MemberAccessExpressionBuilderBase expressionBuilder = ExpressionBuilderFactory.MemberAccess(typeof(T), memberName, checkForNull);
return(expressionBuilder.CreateLambdaExpression());
}