protected void InvokeWithBeforeSetValue(SetValueEventArgs eArg, Action action)
{
if (BeforeSetValue != null)
{
BeforeSetValue(this, eArg);
}
if (!eArg.Cancel)
{
action.Invoke();
}
}
/// <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));
}
}
/// <summary>
/// Add is used by various operations (eg: add, copy, ...), yet through different operations;
/// This method allows code reuse yet reporting the correct operation on error
/// </summary>
private void Add(string path, object value, T objectToApplyTo, Operation <T> operationToReport)
{
// add, in this implementation, does not just "add" properties - that's
// technically impossible; It can however be used to add items to arrays,
// or to replace values.
// first up: if the path ends in a numeric value, we're inserting in a list and
// that value represents the position; if the path ends in "-", we're appending
// to the list.
// get path result
var pathResult = PropertyHelpers.GetActualPropertyPath(
path,
objectToApplyTo,
operationToReport,
true);
var appendList = pathResult.ExecuteAtEnd;
var positionAsInteger = pathResult.NumericEnd;
var actualPathToProperty = pathResult.PathToProperty;
var result = new ObjectTreeAnalysisResult(objectToApplyTo, actualPathToProperty, ContractResolver);
if (!result.IsValidPathForAdd)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: the provided path is invalid: {0}.", path)),
422);
}
// If it' an array, add to that array. If it's not, we replace.
// is the path an array (but not a string (= char[]))? In this case,
// the path must end with "/position" or "/-", which we already determined before.
var patchProperty = result.JsonPatchProperty;
if (appendList || positionAsInteger > -1)
{
if (PropertyHelpers.IsNonStringList(patchProperty.Property.PropertyType))
{
// now, get the generic type of the enumerable
var genericTypeOfArray = PropertyHelpers.GetEnumerableType(patchProperty.Property.PropertyType);
var conversionResult = PropertyHelpers.ConvertToActualType(genericTypeOfArray, value);
if (!conversionResult.CanBeConverted)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided value is invalid for array property type at location path: {0}", path)),
422);
}
if (patchProperty.Property.Readable)
{
var array = (IList)patchProperty.Property.ValueProvider
.GetValue(patchProperty.Parent);
if (array == null)
{
array = (IList)Activator.CreateInstance(typeof(List <>).MakeGenericType(genericTypeOfArray));
patchProperty.Property.ValueProvider.SetValue(patchProperty.Parent, array);
}
if (appendList)
{
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
Index = array.Count + 1,
NewValue = conversionResult.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property
};
InvokeWithBeforeSetValue(eArg, () => array.Add(eArg.NewValue));
}
else
{
// specified index must not be greater than the amount of items in the
// array
if (positionAsInteger <= array.Count)
{
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
Index = positionAsInteger,
NewValue = conversionResult.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property
};
InvokeWithBeforeSetValue(eArg, () => array.Insert(positionAsInteger, eArg.NewValue));
}
else
{
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);
}
}
}
else
{
// cannot read the property
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 if (PropertyHelpers.IsNonStringCollection(patchProperty.Property.PropertyType))
{
// we need to do a little work with collections here. All generic collections have an "Add" operation. In this case, we should ONLY
// support adding to the end.
if (!(positionAsInteger == -1 || appendList))
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided path is invalid for array property type at location path: {0}: can only insert at end of array when target type is ICollection", path)),
422);
}
var genericTypeOfCollection = PropertyHelpers.GetEnumerableType(patchProperty.Property.PropertyType);
ConversionResult conversionResult;// = PropertyHelpers.ConvertToActualType(genericTypeOfCollection, value);
if (!genericTypeOfCollection.IsValueType && genericTypeOfCollection != typeof(string) && value != null && value.GetType() == typeof(string))
{
object newObj;
if (CustomDeserializationHandler != null)
{
newObj = CustomDeserializationHandler(value.ToString(), genericTypeOfCollection);
}
else
{
newObj = JsonConvert.DeserializeObject(value.ToString(), genericTypeOfCollection);
}
conversionResult = new ConversionResult(true, newObj);
}
else if (value != null && genericTypeOfCollection.IsAssignableFrom(value.GetType()))
{
conversionResult = new ConversionResult(true, value);
}
else
{
conversionResult = PropertyHelpers.ConvertToActualType(
genericTypeOfCollection,
value);
}
if (!conversionResult.CanBeConverted)
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: provided value is invalid for array property type at location path: {0}", path)),
422);
}
if (patchProperty.Property.Readable)
{
var array = patchProperty.Property.ValueProvider
.GetValue(patchProperty.Parent);
if (array == null)
{
// the array was null. This might mean we are dealing with a fresh object. This is okay. Lets initialize it with a basic collection.
array = Activator.CreateInstance(typeof(Collection <>).MakeGenericType(genericTypeOfCollection));
patchProperty.Property.ValueProvider.SetValue(patchProperty.Parent, array);
}
var addMethod = patchProperty.Property.PropertyType.GetMethod("Add");
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
Index = -1,
NewValue = conversionResult.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property
};
InvokeWithBeforeSetValue(eArg, () => addMethod.Invoke(array, new object[] { eArg.NewValue }));
}
else
{
// cannot read the property
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
{
Type propType = patchProperty.Property.PropertyType;
ConversionResult conversionResultTuple;
if (!propType.IsValueType && propType != typeof(string) && value != null && value.GetType() == typeof(string))
{
object newObj;
if (CustomDeserializationHandler != null)
{
newObj = CustomDeserializationHandler(value.ToString(), propType);
}
else
{
newObj = JsonConvert.DeserializeObject(value.ToString(), propType);
}
conversionResultTuple = new ConversionResult(true, newObj);
}
else if (value != null && patchProperty.Property.PropertyType.IsAssignableFrom(value.GetType()))
{
conversionResultTuple = new ConversionResult(true, value);
}
else
{
conversionResultTuple = PropertyHelpers.ConvertToActualType(
patchProperty.Property.PropertyType,
value);
}
if (conversionResultTuple.CanBeConverted)
{
if (patchProperty.Property.Writable)
{
SetValueEventArgs eArg = new SetValueEventArgs(operationToReport)
{
Cancel = false,
NewValue = conversionResultTuple.ConvertedInstance,
ParentObject = patchProperty.Parent,
Property = patchProperty.Property
};
InvokeWithBeforeSetValue(eArg, () => patchProperty.Property.ValueProvider.SetValue(
eArg.ParentObject,
eArg.NewValue));
}
else
{
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);
}
}
else
{
throw new JsonPatchException(
new JsonPatchError(
objectToApplyTo,
operationToReport,
string.Format("Patch failed: property value cannot be converted to type of path location {0}.", path)),
422);
}
}
}
