public static string Serialize(SortExpressionCollection collection)
{
TypeConverter converter =
TypeDescriptor.GetConverter(typeof(SortExpressionCollection));
return((string)converter.ConvertTo(collection, typeof(string)));
}
public static string GetSortDescription(string sortMetaData)
{
SortExpressionCollection collection =
GetSortExpressions(sortMetaData);
return(collection.ToString());
}
public static string AddSortExpression(
string sortMetaData,
SortExpression sortExpression)
{
// De-serialize the SortExpressionCollection meta data
SortExpressionCollection collection =
GetSortExpressions(sortMetaData);
int index =
collection.FindIndex(
s => s.Expression == sortExpression.Expression);
if (index == 0)
{
collection[0].ToggleDirection();
}
else
{
if (index > 0)
{
collection.RemoveAt(index);
}
collection.Insert(0, sortExpression);
if (collection.Count > MaxSortSpecifications)
{
collection.RemoveRange(MaxSortSpecifications, 1);
}
}
// Re-serialize the SortExpressionCollection back into meta data
return(collection.Serialize());
}
public override object ConvertFrom(
ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value)
{
if (value == null)
{
return(new SortExpressionCollection());
}
string data = value as string;
if (data == null)
{
return(base.ConvertFrom(context, culture, value));
}
if (data.Length < 1)
{
return(new SortExpressionCollection());
}
string[] elements =
data.Split(new char[] { SortExpressionDelimiter });
if (elements.Length < 1)
{
return(new SortExpressionCollection());
}
SortExpressionCollection collection =
new SortExpressionCollection();
TypeConverter converter =
TypeDescriptor.GetConverter(typeof(SortExpression));
foreach (string element in elements)
{
SortExpression sortExpression =
converter.ConvertFrom(element) as SortExpression;
if (sortExpression != null)
{
collection.Add(sortExpression);
}
}
return(collection);
}
public override object ConvertTo(
ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value,
Type destinationType)
{
if ((value != null) && (!(value is SortExpressionCollection)))
{
string msg = String.Format(
"Unable to convert type '{0}'!", value.GetType());
throw new Exception(msg);
}
SortExpressionCollection collection =
value as SortExpressionCollection;
if (destinationType == typeof(string))
{
if (value == null)
{
return(String.Empty);
}
StringBuilder sb = new StringBuilder();
TypeConverter converter =
TypeDescriptor.GetConverter(typeof(SortExpression));
foreach (SortExpression sortExpression in collection)
{
if (sb.Length > 0)
{
sb.Append(SortExpressionDelimiter);
}
string s =
(string)
converter.ConvertTo(sortExpression, typeof(string));
sb.Append(s);
}
return(sb.ToString());
}
return(base.ConvertTo(context, culture, value, destinationType));
}
public static SortExpressionCollection GetSortExpressions(
string sortMetaData)
{
return(SortExpressionCollection.DeSerialize(sortMetaData));
}
