/// <summary>
/// Remove is used by various operations (eg: remove, move, ...), yet through different operations;
/// This method allows code reuse yet reporting the correct operation on error
/// </summary>
private RemovedPropertyTypeResult Remove(string path, T objectToApplyTo, Operation <T> operationToReport)
{
// get path result
var pathResult = PropertyHelpers.GetActualPropertyPath(
path,
objectToApplyTo,
operationToReport,
false);
var removeFromList = pathResult.ExecuteAtEnd;
var positionAsInteger = pathResult.NumericEnd;
var actualPathToProperty = pathResult.PathToProperty;
var expressionToUse = pathResult.ExpressionEnd;
var result = new ObjectTreeAnalysisResult(objectToApplyTo, actualPathToProperty,
ContractResolver);
if (!result.IsValidPathForRemove)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: the provided path is invalid: {0}.", path)),
422);
}
var patchProperty = result.JsonPatchProperty;
if (removeFromList || positionAsInteger > -1)
{
if (expressionToUse != null)
{
// we have an expression.
var elementType = PropertyHelpers.GetCollectionType(patchProperty.Property.PropertyType);
object coll = patchProperty.Property.ValueProvider
.GetValue(patchProperty.Parent);
var remMethod = typeof(ICollection <>).MakeGenericType(elementType).GetMethod("Remove");
var objToRemove = ExpressionHelpers.GetElementAtFromObjectExpression(coll, expressionToUse);
var remResult = remMethod.Invoke(coll, new object[] { objToRemove });
if ((bool)remResult != true)
{
throw new Exception("D'oh");
}
return(new RemovedPropertyTypeResult(elementType, false));
}
else if (PropertyHelpers.IsNonStringList(patchProperty.Property.PropertyType))
{
// now, get the generic type of the enumerable
var genericTypeOfArray = PropertyHelpers.GetEnumerableType(patchProperty.Property.PropertyType);
if (patchProperty.Property.Readable)
{
var array = (IList)patchProperty.Property.ValueProvider
.GetValue(patchProperty.Parent);
if (removeFromList)
{
if (array.Count == 0)
{
// if the array is empty, we should throw an error
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided path is invalid for array property type at location path: {0}: position larger than array size", path)),
422);
}
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
//NewValue = conversionResultTuple.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property,
Index = array.Count - 1,
};
InvokeWithBeforeSetValue(eArg, () => array.RemoveAt(eArg.Index.Value));
// return the type of the value that has been removed
return(new RemovedPropertyTypeResult(genericTypeOfArray, false));
}
else
{
if (positionAsInteger >= array.Count)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided path is invalid for array property type at location path: {0}: position larger than array size", path)),
422);
}
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
//NewValue = conversionResultTuple.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property,
Index = positionAsInteger
};
InvokeWithBeforeSetValue(eArg, () => array.RemoveAt(eArg.Index.Value));
// return the type of the value that has been removed
return(new RemovedPropertyTypeResult(genericTypeOfArray, false));
}
}
else
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: cannot get property value at path {0}. Possible cause: the property doesn't have an accessible getter.", path)),
422);
}
}
else
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided path is invalid for array property type at location path: {0}: expected array.", path)),
422);
}
}
else
{
if (!patchProperty.Property.Writable)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: property at path location cannot be set: {0}. Possible causes: the property may not have an accessible setter, or the property may be part of an anonymous object (and thus cannot be changed after initialization).", path)),
422);
}
// set value to null, or for non-nullable value types, to its default value.
object value = null;
if (patchProperty.Property.PropertyType.GetType().IsValueType &&
Nullable.GetUnderlyingType(patchProperty.Property.PropertyType) == null)
{
value = Activator.CreateInstance(patchProperty.Property.PropertyType);
}
// check if it can be converted.
var conversionResultTuple = PropertyHelpers.ConvertToActualType(
patchProperty.Property.PropertyType,
value);
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
//NewValue = conversionResultTuple.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property,
IsRemoveStepOfReplace = operationToReport.OperationType == OperationType.Replace
};
if (!conversionResultTuple.CanBeConverted)
{
// conversion failed, so use reflection (somewhat slower) to
// create a new default instance of the property type to set as value
eArg.NewValue = Activator.CreateInstance(patchProperty.Property.PropertyType);
//patchProperty.Property.ValueProvider.SetValue(patchProperty.Parent,
// Activator.CreateInstance(patchProperty.Property.PropertyType));
//return new RemovedPropertyTypeResult(patchProperty.Property.PropertyType, false);
}
else
{
eArg.NewValue = conversionResultTuple.ConvertedInstance;
}
InvokeWithBeforeSetValue(eArg, () => patchProperty.Property.ValueProvider.SetValue(eArg.ParentObject,
eArg.NewValue));
return(new RemovedPropertyTypeResult(patchProperty.Property.PropertyType, false));
}
}