// Remove null children of current node, and return true => current node is null
public static bool RemoveNullChildren(this ElementNode node)
{
if (node == null)
{
return(true);
}
var children = node.Children().Cast <ElementNode>().ToList();
foreach (var child in children)
{
// Remove child if it is null => return true
if (RemoveNullChildren(child))
{
node.Remove(child);
}
}
bool currentNodeIsEmpty = !node.Children().Any() && node.Value == null;
bool currentNodeIsFhirResource = node.IsFhirResource();
if (currentNodeIsEmpty && !currentNodeIsFhirResource)
{
return(true);
}
else
{
return(false);
}
}
public void AccessViaIndexers()
{
Assert.Equal("Patient.active[0].extension[1].value[0]", patient["active"][0]["extension"][1]["value"][0].Location);
Assert.Equal("Patient.active[0].extension[1].value[0]", patient["active"]["extension"][1]["value"].Single().Location);
Assert.Equal("Patient.active[0].extension[0].value[0]", patient.Children("active").First()
.Children("extension").First()
.Children("value").First().Location);
Assert.Equal("Patient.active[0].extension[0].value[0]", patient.Children("active")
.Children("extension").First()
.Children("value").Single().Location);
}
public ProcessResult Process(ElementNode node, ProcessContext context = null, Dictionary <string, object> settings = null)
{
EnsureArg.IsNotNull(node);
EnsureArg.IsNotNull(context?.VisitedNodes);
EnsureArg.IsNotNull(settings);
var result = new ProcessResult();
ElementNode valueNode = null;
if (s_primitiveValueTypeNames.Contains(node.InstanceType, StringComparer.InvariantCultureIgnoreCase))
{
valueNode = node;
}
else if (s_quantityTypeNames.Contains(node.InstanceType, StringComparer.InvariantCultureIgnoreCase))
{
valueNode = node.Children(Constants.ValueNodeName).Cast <ElementNode>().FirstOrDefault();
}
// Perturb will not happen if value node is empty or visited.
if (valueNode?.Value == null || context.VisitedNodes.Contains(valueNode))
{
return(result);
}
var perturbSetting = PerturbSetting.CreateFromRuleSettings(settings);
AddNoise(valueNode, perturbSetting);
context.VisitedNodes.UnionWith(node.Descendants().Cast <ElementNode>());
result.AddProcessRecord(AnonymizationOperations.Perturb, node);
return(result);
}
public ProcessResult ProcessNodeRecursive(ElementNode node, IAnonymizerProcessor processor,
ProcessContext context, Dictionary <string, object> settings)
{
var result = new ProcessResult();
if (_visitedNodes.Contains(node))
{
return(result);
}
result = processor.Process(node, context, settings);
_visitedNodes.Add(node);
foreach (var child in node.Children().CastElementNodes())
{
if (child.IsFhirResource())
{
continue;
}
result.Update(ProcessNodeRecursive(child, processor, context, settings));
}
return(result);
}
private static void TransformTypeRulesToPathRules(ElementNode node, Dictionary <string, string> typeRules, List <AnonymizerRule> rules, HashSet <string> rulePaths)
{
if (node.IsContainedNode() || node.IsEntryNode())
{
return;
}
string path = node.GetFhirPath();
if (rulePaths.Contains(path))
{
return;
}
if (typeRules.ContainsKey(node.InstanceType))
{
var rule = new AnonymizerRule(path, typeRules[node.InstanceType], AnonymizerRuleType.TypeRule, node.InstanceType);
rules.Add(rule);
rulePaths.Add(rule.Path);
}
var children = node.Children().Cast <ElementNode>();
foreach (var child in children)
{
TransformTypeRulesToPathRules(child, typeRules, rules, rulePaths);
}
}
// Post-process to mark all substituted children nodes as visited
private void MarkSubstitutedFragmentAsVisited(ElementNode node, HashSet <ElementNode> visitedNodes)
{
visitedNodes.Add(node);
foreach (var child in node.Children().Cast <ElementNode>())
{
MarkSubstitutedFragmentAsVisited(child, visitedNodes);
}
}
public static List <ElementNode> GetEntryResourceChildren(this ElementNode node)
{
return(node?.Children(s_entryNodeName)
.Select(entry => entry?.Children(s_resourceNodeName).FirstOrDefault())
.Where(resource => resource != null)
.Cast <ElementNode>()
.ToList());
}
public static void RemoveNullChildren(this ElementNode node)
{
if (node == null)
{
return;
}
var children = node.Children().Cast <ElementNode>().ToList();
foreach (var child in children)
{
RemoveNullChildren(child);
}
if (!node.Children().Any() && node.Value == null && !Enum.TryParse <ResourceType>(node.InstanceType, true, out _))
{
node.Parent.Remove(node);
return;
}
}
private static string TryGetResourceId(ElementNode node)
{
while (node.Parent != null)
{
node = node.Parent;
}
var id = node.Children("id").FirstOrDefault();
return(id != null?id.Value.ToString() : string.Empty);
}
public static void Accept(this ElementNode node, AbstractElementNodeVisitor visitor)
{
bool shouldVisitChild = visitor.Visit(node);
if (shouldVisitChild)
{
foreach (var child in node.Children().Cast <ElementNode>())
{
child.Accept(visitor);
}
}
visitor.EndVisit(node);
}
public static IEnumerable <ElementNode> ResourceDescendantsWithoutSubResource(this ElementNode node)
{
foreach (var child in node.Children().Cast <ElementNode>())
{
// Skip sub resources in bundle entry and contained list
if (child.IsFhirResource())
{
continue;
}
yield return(child);
foreach (var n in child.ResourceDescendantsWithoutSubResource())
{
yield return(n);
}
}
}
// To keep consistent anonymization changes made by preceding rules, we should figure out whether a node can be removed during substitution
private bool GenerateKeepNodeSetForSubstitution(ElementNode node, HashSet <ElementNode> visitedNodes, HashSet <ElementNode> keepNodes)
{
var shouldKeep = false;
// If a child (no matter how deep) has been modified, this node should be kept
foreach (var child in node.Children().Cast <ElementNode>())
{
shouldKeep |= GenerateKeepNodeSetForSubstitution(child, visitedNodes, keepNodes);
}
// If this node its self has been modified, it should be kept
if (shouldKeep || visitedNodes.Contains(node))
{
keepNodes.Add(node);
return(true);
}
return(shouldKeep);
}
private void AnonymizeChildNode(ElementNode node, string method, HashSet <string> rulePathSet)
{
method = method.ToUpperInvariant();
if (node.Value != null && _processors.ContainsKey(method))
{
_processors[method].Process(node);
}
var children = node.Children().Cast <ElementNode>();
foreach (var child in children)
{
if (!rulePathSet.Contains(child.GetFhirPath()))
{
AnonymizeChildNode(child, method, rulePathSet);
}
}
}
private void AnonymizeChildNode(ElementNode node, AnonymizerRule rule, HashSet <string> rulePathSet, string resourceId)
{
var method = rule.Method.ToUpperInvariant();
if (node.Value != null && _processors.ContainsKey(method))
{
_processors[method].Process(node);
_logger.LogDebug($"{node.GetFhirPath()} in resource ID {resourceId} is applied {method} due to rule \"{rule.Source}:{rule.Method}\"");
}
var children = node.Children().Cast <ElementNode>();
foreach (var child in children)
{
if (!rulePathSet.Contains(child.GetFhirPath()))
{
AnonymizeChildNode(child, rule, rulePathSet, resourceId);
}
}
}
public static void RemoveEmptyNodes(this ElementNode node)
{
if (node == null)
{
return;
}
var children = node.Children().ToList();
foreach (var child in children)
{
var elementNodeChild = (ElementNode)child;
// Remove empty nodes recursively
RemoveEmptyNodes(elementNodeChild);
if (IsEmptyNode(elementNodeChild))
{
node.Remove(elementNodeChild);
}
}
}
public ProcessResult ProcessNodeRecursive(ElementNode node, IAnonymizerProcessor processor, HashSet <ElementNode> visitedNodes)
{
ProcessResult result = new ProcessResult();
if (visitedNodes.Contains(node))
{
return(result);
}
result = processor.Process(node);
visitedNodes.Add(node);
foreach (var child in node.Children().Cast <ElementNode>())
{
if (child.IsFhirResource())
{
continue;
}
result.Update(ProcessNodeRecursive(child, processor, visitedNodes));
}
return(result);
}
public static ElementNode GetMeta(this ElementNode node)
{
return(node?.Children("meta").Cast <ElementNode>().FirstOrDefault());
}
public static string GetNodeId(this ElementNode node)
{
var id = node.Children("id").FirstOrDefault();
return(id?.Value?.ToString() ?? string.Empty);
}
public static bool HasContainedNode(this ElementNode node)
{
return(node != null && node.Children(Constants.ContainedNodeName).Any());
}
public static List <ElementNode> GetContainedChildren(this ElementNode node)
{
return(node?.Children(s_containedNodeName).Cast <ElementNode>().ToList());
}
private ProcessResult SubstituteNode(ElementNode node, ElementNode replacementNode, HashSet <ElementNode> visitedNodes, HashSet <ElementNode> keepNodes)
{
var processResult = new ProcessResult();
if (node == null || replacementNode == null || visitedNodes.Contains(node))
{
return(processResult);
}
// children names to replace, multiple to multiple replacement
var replaceChildrenNames = replacementNode.Children().Select(element => element.Name).ToHashSet();
foreach (var name in replaceChildrenNames)
{
var children = node.Children(name).Cast <ElementNode>().ToList();
var targetChildren = replacementNode.Children(name).Cast <ElementNode>().ToList();
int i = 0;
foreach (var child in children)
{
if (visitedNodes.Contains(child))
{
// Skip replacement if child already processed before.
i++;
continue;
}
else if (i < targetChildren.Count)
{
// We still have target nodes, do replacement
SubstituteNode(child, targetChildren[i++], visitedNodes, keepNodes);
}
else if (keepNodes.Contains(child))
{
// Substitute with an empty node when no target node available but we need to keep this node
SubstituteNode(child, GetDummyNode(), visitedNodes, keepNodes);
}
else
{
// Remove source node when no target node available and we don't need to keep the source node
node.Remove(child);
}
}
while (i < targetChildren.Count)
{
// Add extra target nodes, create a new copy before adding
node.Add(s_provider, ElementNode.FromElement(targetChildren[i++]));
}
}
// children nodes not presented in replacement value, we need either remove or keep a dummy copy
var nonReplacementChildren = node.Children()
.Where(element => !replaceChildrenNames.Contains(element.Name))
.Cast <ElementNode>().ToList();
foreach (var child in nonReplacementChildren)
{
if (visitedNodes.Contains(child))
{
continue;
}
else if (keepNodes.Contains(child))
{
SubstituteNode(child, GetDummyNode(), visitedNodes, keepNodes);
}
else
{
node.Remove(child);
}
}
node.Value = replacementNode.Value;
processResult.AddProcessRecord(AnonymizationOperations.Substitute, node);
return(processResult);
}
