public static Func <T, bool> ToPredicate <T>(this PathFilterExpression filterExpression)
{
if (filterExpression == null)
{
return(user => true);
}
if (string.IsNullOrWhiteSpace(filterExpression.Filter))
{
throw new Exception("Invalid scim filter"); // TODO: (DG) exception handling
}
// parse our filter into an expression tree
var declaryingType = filterExpression.Path == null
? typeof(T)
: typeof(T)
.GetProperty(filterExpression.Path, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase)
.PropertyType;
// if enumerable, get generic argument
if (declaryingType.IsNonStringEnumerable())
{
declaryingType = declaryingType.GetGenericArguments()[0];
}
var lexer = new ScimFilterLexer(new AntlrInputStream(filterExpression.Filter));
var parser = new ScimFilterParser(new CommonTokenStream(lexer));
// create a visitor for the type of enumerable generic argument
var filterVisitorType = typeof(ScimFilterVisitor <>).MakeGenericType(declaryingType);
var filterVisitor = (IScimFilterVisitor)filterVisitorType.CreateInstance();
var filterDelegateExpression = filterVisitor.VisitExpression(parser.parse());
if (filterExpression.Path == null)
{
return(filterDelegateExpression.Compile().AsFunc <T, bool>());
}
// TODO: (DG) add more comments
var resourceArg = Expression.Parameter(typeof(T));
var resourceComplexAttr = Expression.Property(resourceArg, filterExpression.Path);
var invokeFilterExpression = Expression.Invoke(filterDelegateExpression, resourceComplexAttr);
var predicate = Expression.Lambda <Func <T, bool> >(invokeFilterExpression, resourceArg);
return(predicate.Compile().AsFunc <T, bool>());
}
private IEnumerable<Node> GetAffectedMembers(
IList<PathFilterExpression> pathTree,
ref int lastPosition,
Node node)
{
for (int i = lastPosition; i < pathTree.Count; i++)
{
// seems absurd, but this MAY be called recursively, OR simply
// iterated via the for loop
lastPosition = i;
var jsonContract = (JsonObjectContract)_ContractResolver.ResolveContract(node.Target.GetType());
var attemptedProperty = jsonContract.Properties.GetClosestMatchProperty(pathTree[i].Path);
if (attemptedProperty == null)
{
if (!_ServerConfiguration.ResourceExtensionExists(pathTree[i].Path))
{
// property cannot be found, and we're not working with an extension.
ErrorType = ScimErrorType.InvalidPath;
break;
}
// this is a resource extension
// TODO: (DG) the code below works as well and will remove once it's determined how
// repositories will access and persist extension data. Currently, Extensions property is public.
// var memberInfo = node.Target.GetType().GetProperty("Extensions", BindingFlags.NonPublic | BindingFlags.Instance);
// var property = new JsonProperty
// {
// PropertyType = memberInfo.PropertyType,
// DeclaringType = memberInfo.DeclaringType,
// ValueProvider = new ReflectionValueProvider(memberInfo),
// AttributeProvider = new ReflectionAttributeProvider(memberInfo),
// Readable = true,
// Writable = true,
// ShouldSerialize = member => false
// };
attemptedProperty = jsonContract.Properties.GetProperty("extensions", StringComparison.Ordinal);
}
// if there's nothing to filter and we're not yet at the last path entry, continue
if (pathTree[i].Filter == null && i != pathTree.Count - 1)
{
// if they enter an invalid target
if (attemptedProperty.PropertyType.IsTerminalObject())
{
ErrorType = ScimErrorType.InvalidPath;
break;
}
object targetValue;
var propertyType = attemptedProperty.PropertyType;
// support for resource extensions
if (propertyType == typeof (ResourceExtensions))
{
var resourceExtensions = (ResourceExtensions) attemptedProperty.ValueProvider.GetValue(node.Target);
var extensionType = _ServerConfiguration.GetResourceExtensionType(node.Target.GetType(), pathTree[i].Path);
if (_Operation.OperationType == OperationType.Remove && !resourceExtensions.Contains(extensionType))
break;
targetValue = resourceExtensions.GetOrCreate(extensionType);
}
else
{
// if targetValue is null, then we need to initialize it, UNLESS we're in a remove operation
// e.g. user.name.givenName, when name == null
targetValue = attemptedProperty.ValueProvider.GetValue(node.Target);
if (targetValue == null)
{
if (_Operation.OperationType == OperationType.Remove)
break;
if (!propertyType.IsNonStringEnumerable())
{
// if just a normal complex type, just create a new instance
targetValue = propertyType.CreateInstance();
}
else
{
var enumerableInterface = propertyType.GetEnumerableType();
var listArgumentType = enumerableInterface.GetGenericArguments()[0];
var listType = typeof (List<>).MakeGenericType(listArgumentType);
targetValue = listType.CreateInstance();
}
attemptedProperty.ValueProvider.SetValue(node.Target, targetValue);
}
}
// the Target becomes the Target's child property value
// the Parent becomes the current Target
node = new Node(targetValue, node.Target);
continue; // keep traversing the path tree
}
if (pathTree[i].Filter != null)
{
// we can only filter enumerable types
if (!attemptedProperty.PropertyType.IsNonStringEnumerable())
{
ErrorType = ScimErrorType.InvalidFilter;
break;
}
var enumerable = attemptedProperty.ValueProvider.GetValue(node.Target) as IEnumerable;
if (enumerable == null)
{
// if the value of the attribute is null then there's nothing to filter
// it should never get here beause ScimObjectAdapter should apply a
// different ruleset for null values; replacing or setting the attribute value
ErrorType = ScimErrorType.NoTarget;
break;
}
dynamic predicate;
try
{
// parse our filter into an expression tree
var lexer = new ScimFilterLexer(new AntlrInputStream(pathTree[i].Filter));
var parser = new ScimFilterParser(new CommonTokenStream(lexer));
// create a visitor for the type of enumerable generic argument
var enumerableType = attemptedProperty.PropertyType.GetGenericArguments()[0];
var filterVisitorType = typeof (ScimFilterVisitor<>).MakeGenericType(enumerableType);
var filterVisitor = (IScimFilterVisitor) filterVisitorType.CreateInstance(_ServerConfiguration);
predicate = filterVisitor.VisitExpression(parser.parse()).Compile();
}
catch (Exception)
{
ErrorType = ScimErrorType.InvalidFilter;
break;
}
// we have an enumerable and a filter predicate
// for each element in the enumerable that satisfies the predicate,
// visit that element as part of the path tree
var originalHasElements = false;
var filteredNodes = new List<Node>();
var enumerator = enumerable.GetEnumerator();
lastPosition = i + 1; // increase the position in the tree
while (enumerator.MoveNext())
{
originalHasElements = true;
dynamic currentElement = enumerator.Current;
if ((bool) predicate(currentElement))
{
filteredNodes.AddRange(
GetAffectedMembers(
pathTree,
ref lastPosition,
new Node(enumerator.Current, node.Target)));
}
}
/* SCIM PATCH 'replace' RULE:
o If the target location is a multi-valued attribute for which a
value selection filter ("valuePath") has been supplied and no
record match was made, the service provider SHALL indicate failure
by returning HTTP status code 400 and a "scimType" error code of
"noTarget".
*/
if (originalHasElements &&
filteredNodes.Count == 0 &&
_Operation != null &&
_Operation.OperationType == OperationType.Replace)
{
throw new ScimPatchException(
ScimErrorType.NoTarget, _Operation);
}
return filteredNodes;
}
}
return new List<Node> { node };
}
private IEnumerable <Node> GetAffectedMembers(
IList <PathFilterExpression> pathTree,
ref int lastPosition,
Node node)
{
for (int i = lastPosition; i < pathTree.Count; i++)
{
// seems absurd, but this MAY be called recursively, OR simply
// iterated via the for loop
lastPosition = i;
var jsonContract = (JsonObjectContract)_ContractResolver.ResolveContract(node.Target.GetType());
var attemptedProperty = jsonContract.Properties.GetClosestMatchProperty(pathTree[i].Path);
if (attemptedProperty == null)
{
if (!_ServerConfiguration.ResourceExtensionExists(pathTree[i].Path))
{
// property cannot be found, and we're not working with an extension.
ErrorType = ScimErrorType.InvalidPath;
break;
}
// this is a resource extension
// TODO: (DG) the code below works as well and will remove once it's determined how
// repositories will access and persist extension data. Currently, Extensions property is public.
// var memberInfo = node.Target.GetType().GetProperty("Extensions", BindingFlags.NonPublic | BindingFlags.Instance);
// var property = new JsonProperty
// {
// PropertyType = memberInfo.PropertyType,
// DeclaringType = memberInfo.DeclaringType,
// ValueProvider = new ReflectionValueProvider(memberInfo),
// AttributeProvider = new ReflectionAttributeProvider(memberInfo),
// Readable = true,
// Writable = true,
// ShouldSerialize = member => false
// };
attemptedProperty = jsonContract.Properties.GetProperty("extensions", StringComparison.Ordinal);
}
// if there's nothing to filter and we're not yet at the last path entry, continue
if (pathTree[i].Filter == null && i != pathTree.Count - 1)
{
// if they enter an invalid target
if (attemptedProperty.PropertyType.IsTerminalObject())
{
ErrorType = ScimErrorType.InvalidPath;
break;
}
object targetValue;
var propertyType = attemptedProperty.PropertyType;
// support for resource extensions
if (propertyType == typeof(ResourceExtensions))
{
var resourceExtensions = (ResourceExtensions)attemptedProperty.ValueProvider.GetValue(node.Target);
var extensionType = _ServerConfiguration.GetResourceExtensionType(node.Target.GetType(), pathTree[i].Path);
if (_Operation.OperationType == OperationType.Remove && !resourceExtensions.Contains(extensionType))
{
break;
}
targetValue = resourceExtensions.GetOrCreate(extensionType);
}
else
{
// if targetValue is null, then we need to initialize it, UNLESS we're in a remove operation
// e.g. user.name.givenName, when name == null
targetValue = attemptedProperty.ValueProvider.GetValue(node.Target);
if (targetValue == null)
{
if (_Operation.OperationType == OperationType.Remove)
{
break;
}
if (!propertyType.IsNonStringEnumerable())
{
// if just a normal complex type, just create a new instance
targetValue = propertyType.CreateInstance();
}
else
{
var enumerableInterface = propertyType.GetEnumerableType();
var listArgumentType = enumerableInterface.GetGenericArguments()[0];
var listType = typeof(List <>).MakeGenericType(listArgumentType);
targetValue = listType.CreateInstance();
}
attemptedProperty.ValueProvider.SetValue(node.Target, targetValue);
}
}
// the Target becomes the Target's child property value
// the Parent becomes the current Target
node = new Node(targetValue, node.Target);
continue; // keep traversing the path tree
}
if (pathTree[i].Filter != null)
{
// we can only filter enumerable types
if (!attemptedProperty.PropertyType.IsNonStringEnumerable())
{
ErrorType = ScimErrorType.InvalidFilter;
break;
}
var enumerable = attemptedProperty.ValueProvider.GetValue(node.Target) as IEnumerable;
if (enumerable == null)
{
// if the value of the attribute is null then there's nothing to filter
// it should never get here beause ScimObjectAdapter should apply a
// different ruleset for null values; replacing or setting the attribute value
ErrorType = ScimErrorType.NoTarget;
break;
}
dynamic predicate;
try
{
// parse our filter into an expression tree
var lexer = new ScimFilterLexer(new AntlrInputStream(pathTree[i].Filter));
var parser = new ScimFilterParser(new CommonTokenStream(lexer));
// create a visitor for the type of enumerable generic argument
var enumerableType = attemptedProperty.PropertyType.GetGenericArguments()[0];
var filterVisitorType = typeof(ScimFilterVisitor <>).MakeGenericType(enumerableType);
var filterVisitor = (IScimFilterVisitor)filterVisitorType.CreateInstance(_ServerConfiguration);
predicate = filterVisitor.VisitExpression(parser.parse()).Compile();
}
catch (Exception)
{
ErrorType = ScimErrorType.InvalidFilter;
break;
}
// we have an enumerable and a filter predicate
// for each element in the enumerable that satisfies the predicate,
// visit that element as part of the path tree
var originalHasElements = false;
var filteredNodes = new List <Node>();
var enumerator = enumerable.GetEnumerator();
lastPosition = i + 1; // increase the position in the tree
while (enumerator.MoveNext())
{
originalHasElements = true;
dynamic currentElement = enumerator.Current;
if ((bool)predicate(currentElement))
{
filteredNodes.AddRange(
GetAffectedMembers(
pathTree,
ref lastPosition,
new Node(enumerator.Current, node.Target)));
}
}
/* SCIM PATCH 'replace' RULE:
* o If the target location is a multi-valued attribute for which a
* value selection filter ("valuePath") has been supplied and no
* record match was made, the service provider SHALL indicate failure
* by returning HTTP status code 400 and a "scimType" error code of
* "noTarget".
*/
if (originalHasElements &&
filteredNodes.Count == 0 &&
_Operation != null &&
_Operation.OperationType == OperationType.Replace)
{
throw new ScimPatchException(
ScimErrorType.NoTarget, _Operation);
}
return(filteredNodes);
}
}
return(new List <Node> {
node
});
}
