/// <summary>Deserialize by reading element from the tree reader.</summary>
public static void DeserializeFrom(this IList obj, string elementName, ITreeReader reader)
{
// Check if the list is null
if (obj == null)
{
throw new Exception("List passed to DeserializeFrom method for element {elementName} is null.");
}
// If the list is not empty, error message because the
// object must be empty prior to parsing
if (obj.Count > 0)
{
throw new Exception("List passed to DeserializeFrom method for element {elementName} is not empty.");
}
// Get item type from list type using reflection
Type listType = obj.GetType();
if (!listType.IsGenericType)
{
throw new Exception(
$"Type {listType} cannot be serialized because it implements only IList but not IList<T>.");
}
Type[] genericParameterTypes = listType.GenericTypeArguments;
if (genericParameterTypes.Length != 1)
{
throw new Exception(
$"Generic parameter type list {genericParameterTypes} has more than " +
$"one element creating an ambiguity for deserialization code.");
}
Type itemType = genericParameterTypes[0];
// Select XML node list with the specified name and iterate over XML nodes
IEnumerable <ITreeReader> selectedXmlNodes = reader.ReadElements(elementName);
foreach (ITreeReader selectedXmlNode in selectedXmlNodes)
{
if (selectedXmlNode == null)
{
// Add null value
obj.Add(null);
}
else
{
// Switch on item type
if (itemType == typeof(string))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
obj.Add(token);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(double) || itemType == typeof(double?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = double.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(bool) || itemType == typeof(bool?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = bool.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(int) || itemType == typeof(int?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = int.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(long) || itemType == typeof(long?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = long.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(LocalDate) || itemType == typeof(LocalDate?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = LocalDateUtil.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(LocalTime) || itemType == typeof(LocalTime?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = LocalTimeUtil.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(LocalMinute) || itemType == typeof(LocalMinute?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = LocalMinuteUtil.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(LocalDateTime) || itemType == typeof(LocalDateTime?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = LocalDateTimeUtil.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType == typeof(Instant) || itemType == typeof(Instant?))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = InstantUtil.Parse(token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else if (itemType.IsSubclassOf(typeof(Enum)))
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
var value = Enum.Parse(itemType, token);
obj.Add(value);
}
else
{
obj.Add(null);
}
}
else
{
// If none of the supported atomic types match, use the activator
// to create and empty instance of a complex type and populate it
var item = Activator.CreateInstance(itemType);
switch (item)
{
case ICollection collectionItem:
throw new Exception($"Deserialization is not supported for element {elementName} " +
$"which is collection containing another collection.");
case Data dataItem:
var keyItem = dataItem as Key;
if (keyItem != null)
{
string token = selectedXmlNode.ReadValue();
if (!string.IsNullOrEmpty(token))
{
// Parse semicolon delimited token to populate key item
keyItem.PopulateFrom(token);
obj.Add(item);
}
else
{
obj.Add(null);
}
}
else
{
// Deserialize data item
dataItem.DeserializeFrom(selectedXmlNode);
obj.Add(item);
}
break;
default:
// Error message if the type does not match any of the value or reference types
throw new Exception($"Serialization is not supported for type {itemType}.");
}
}
}
}
}