protected internal override IValueRef GetValueRef(ExpressionState state)
{
var op = state.GetActiveContextObject();
var operand = op.Value;
var selectionCriteria = _children[0];
if (operand is System.Collections.IDictionary mapdata)
{
// Don't lose generic info for the new map
var result = new Dictionary <object, object>();
object lastKey = null;
foreach (DictionaryEntry entry in mapdata)
{
try
{
var kvPair = new TypedValue(entry);
state.PushActiveContextObject(kvPair);
state.EnterScope();
var val = selectionCriteria.GetValueInternal(state).Value;
if (val is bool boolean)
{
if (boolean)
{
if (_variant == FIRST)
{
result[entry.Key] = entry.Value;
return(new TypedValueHolderValueRef(new TypedValue(result), this));
}
result[entry.Key] = entry.Value;
lastKey = entry.Key;
}
}
else
{
throw new SpelEvaluationException(selectionCriteria.StartPosition, SpelMessage.RESULT_OF_SELECTION_CRITERIA_IS_NOT_BOOLEAN);
}
}
finally
{
state.PopActiveContextObject();
state.ExitScope();
}
}
if ((_variant == FIRST || _variant == LAST) && result.Count == 0)
{
return(new TypedValueHolderValueRef(new TypedValue(null), this));
}
if (_variant == LAST)
{
var resultMap = new Dictionary <object, object>();
result.TryGetValue(lastKey, out var lastValue);
resultMap[lastKey] = lastValue;
return(new TypedValueHolderValueRef(new TypedValue(resultMap), this));
}
return(new TypedValueHolderValueRef(new TypedValue(result), this));
}
if (operand is IEnumerable)
{
var operandAsArray = operand as Array;
var data = operand as IEnumerable;
var result = new List <object>();
var index = 0;
foreach (var element in data)
{
try
{
state.PushActiveContextObject(new TypedValue(element));
state.EnterScope("index", index);
var val = selectionCriteria.GetValueInternal(state).Value;
if (val is bool boolean)
{
if (boolean)
{
if (_variant == FIRST)
{
return(new TypedValueHolderValueRef(new TypedValue(element), this));
}
result.Add(element);
}
}
else
{
throw new SpelEvaluationException(selectionCriteria.StartPosition, SpelMessage.RESULT_OF_SELECTION_CRITERIA_IS_NOT_BOOLEAN);
}
index++;
}
finally
{
state.ExitScope();
state.PopActiveContextObject();
}
}
if ((_variant == FIRST || _variant == LAST) && result.Count == 0)
{
return(NullValueRef.INSTANCE);
}
if (_variant == LAST)
{
var lastElem = result == null || result.Count == 0 ? null : result[result.Count - 1];
return(new TypedValueHolderValueRef(new TypedValue(lastElem), this));
}
if (operand is IEnumerable && operandAsArray == null)
{
return(new TypedValueHolderValueRef(new TypedValue(result), this));
}
// Array
if (operandAsArray != null)
{
Type elementType = null;
var typeDesc = op.TypeDescriptor;
if (typeDesc != null)
{
elementType = ReflectionHelper.GetElementTypeDescriptor(typeDesc);
}
if (elementType == null)
{
throw new InvalidOperationException("Unresolvable element type");
}
var resultArray = Array.CreateInstance(elementType, result.Count);
Array.Copy(result.ToArray(), 0, resultArray, 0, result.Count);
return(new TypedValueHolderValueRef(new TypedValue(resultArray), this));
}
}
if (operand == null)
{
if (_nullSafe)
{
return(NullValueRef.INSTANCE);
}
throw new SpelEvaluationException(StartPosition, SpelMessage.INVALID_TYPE_FOR_SELECTION, "null");
}
throw new SpelEvaluationException(StartPosition, SpelMessage.INVALID_TYPE_FOR_SELECTION, operand.GetType().FullName);
}
protected internal override IValueRef GetValueRef(ExpressionState state)
{
var op = state.GetActiveContextObject();
var operand = op.Value;
var operandAsArray = operand as Array;
// TypeDescriptor operandTypeDescriptor = op.getTypeDescriptor();
// When the input is a map, we push a special context object on the stack
// before calling the specified operation. This special context object
// has two fields 'key' and 'value' that refer to the map entries key
// and value, and they can be referenced in the operation
// eg. {'a':'y','b':'n'}.![value=='y'?key:null]" == ['a', null]
if (operand is IDictionary)
{
var mapData = (IDictionary)operand;
var result = new List <object>();
foreach (var entry in mapData)
{
try
{
state.PushActiveContextObject(new TypedValue(entry));
state.EnterScope();
result.Add(_children[0].GetValueInternal(state).Value);
}
finally
{
state.PopActiveContextObject();
state.ExitScope();
}
}
return(new TypedValueHolderValueRef(new TypedValue(result), this)); // TODO unable to build correct type descriptor
}
if (operand is IEnumerable)
{
var data = operand as IEnumerable;
var result = new List <object>();
Type arrayElementType = null;
foreach (var element in data)
{
try
{
state.PushActiveContextObject(new TypedValue(element));
state.EnterScope("index", result.Count);
var value = _children[0].GetValueInternal(state).Value;
if (value != null && operandAsArray != null)
{
arrayElementType = DetermineCommonType(arrayElementType, value.GetType());
}
result.Add(value);
}
finally
{
state.ExitScope();
state.PopActiveContextObject();
}
}
if (operandAsArray != null)
{
if (arrayElementType == null)
{
arrayElementType = typeof(object);
}
var resultArray = Array.CreateInstance(arrayElementType, result.Count);
Array.Copy(result.ToArray(), 0, resultArray, 0, result.Count);
return(new TypedValueHolderValueRef(new TypedValue(resultArray), this));
}
return(new TypedValueHolderValueRef(new TypedValue(result), this));
}
if (operand == null)
{
if (_nullSafe)
{
return(NullValueRef.INSTANCE);
}
throw new SpelEvaluationException(StartPosition, SpelMessage.PROJECTION_NOT_SUPPORTED_ON_TYPE, "null");
}
throw new SpelEvaluationException(StartPosition, SpelMessage.PROJECTION_NOT_SUPPORTED_ON_TYPE, operand.GetType().FullName);
}