/// <summary>
/// Evaluates the function.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="args">The function arguments.</param>
/// <returns>The result value of the function evaluation.</returns>
public override EvaluationValue Evaluate( EvaluationContext context, params inf.IFunctionParameter[] args )
{
if (context == null) throw new ArgumentNullException("context");
if (args == null) throw new ArgumentNullException("args");
BagValue retBag = new BagValue( DataType );
inf.IFunction functionDup = DataType.IsInFunction;
foreach( object par1 in args[0].Elements )
{
EvaluationValue retVal = functionDup.Evaluate( context, new EvaluationValue( par1, args[0].GetType( context ) ), retBag );
if( !retVal.BoolValue )
{
retBag.Add( new EvaluationValue( par1, args[0].GetType( context ) ) );
}
}
foreach( object par2 in args[1].Elements )
{
EvaluationValue retVal = functionDup.Evaluate( context, new EvaluationValue( par2, args[1].GetType( context ) ), retBag );
if( !retVal.BoolValue )
{
retBag.Add( new EvaluationValue( par2, args[1].GetType( context ) ) );
}
}
return new EvaluationValue( retBag, DataType );
}
/// <summary>
/// Evaluates the function.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="args">The function arguments.</param>
/// <returns>The result value of the function evaluation.</returns>
public override EvaluationValue Evaluate( EvaluationContext context, params inf.IFunctionParameter[] args )
{
if (context == null) throw new ArgumentNullException("context");
if (args == null) throw new ArgumentNullException("args");
inf.IDataType type = DataType;
BagValue bag = new BagValue( type );
for( int i = 0; i < args.Length; i++ )
{
bag.Add( args[ i ].GetTypedValue( type, i ) );
}
return new EvaluationValue( bag, type );
}
/// <summary>
/// Method called by the EvaluationEngine to evaluate the function.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="args">The IFuctionParameters that will be used as arguments to the function.</param>
/// <returns></returns>
public override EvaluationValue Evaluate( EvaluationContext context, params inf.IFunctionParameter[] args )
{
if (context == null) throw new ArgumentNullException("context");
if (args == null) throw new ArgumentNullException("args");
inf.IFunction function = args[0].GetFunction( 0 );
if( !args[ 1 ].IsBag )
{
return EvaluationValue.False;
}
BagValue retVal = new BagValue( args[1].GetType( context ) );
foreach( object par in args[1].Elements )
{
retVal.Add(
function.Evaluate(
context,
new EvaluationValue( par, args[1].GetType( context ) ) ) );
}
return new EvaluationValue( retVal, args[1].GetType( context ) );
}
/// <summary>
/// Evaluates the variable into a value.
/// </summary>
/// <param name="context">The contex of the evaluation.</param>
/// <returns>The value of the function.</returns>
public EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
context.Trace("Evaluating variable");
context.AddIndent();
try
{
if (_variableDefinition.Expression is pol.ApplyElement)
{
context.Trace("Apply within condition.");
// There is a nested apply un this policy a new Apply will be created and also
// evaluated. It's return value will be used as the processed argument.
Apply _childApply = new Apply((pol.ApplyElement)_variableDefinition.Expression);
// Evaluate the Apply
_value = _childApply.Evaluate(context);
context.TraceContextValues();
return(_value);
}
else if (_variableDefinition.Expression is pol.FunctionElement)
{
throw new NotImplementedException("FunctionElement"); //TODO:
}
else if (_variableDefinition.Expression is pol.VariableReferenceElement)
{
pol.VariableReferenceElement variableRef = _variableDefinition.Expression as pol.VariableReferenceElement;
VariableDefinition variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition;
context.TraceContextValues();
if (!variableDef.IsEvaluated)
{
return(variableDef.Evaluate(context));
}
else
{
return(variableDef.Value);
}
}
else if (_variableDefinition.Expression is pol.AttributeValueElementReadWrite)
{
// The AttributeValue does not need to be processed
context.Trace("Attribute value {0}", _variableDefinition.Expression.ToString());
pol.AttributeValueElementReadWrite att = (pol.AttributeValueElementReadWrite)_variableDefinition.Expression;
pol.AttributeValueElement attributeValue = new pol.AttributeValueElement(att.DataType, att.Contents, att.SchemaVersion);
_value = new EvaluationValue(
attributeValue.GetTypedValue(attributeValue.GetType(context), 0),
attributeValue.GetType(context));
return(_value);
}
else if (_variableDefinition.Expression is pol.AttributeDesignatorBase)
{
// Resolve the AttributeDesignator using the EvaluationEngine public methods.
context.Trace("Processing attribute designator: {0}", _variableDefinition.Expression.ToString());
pol.AttributeDesignatorBase attrDes = (pol.AttributeDesignatorBase)_variableDefinition.Expression;
BagValue bag = EvaluationEngine.Resolve(context, attrDes);
// If the attribute was not resolved by the EvaluationEngine search the
// attribute in the context document, also using the EvaluationEngine public
// methods.
if (bag.BagSize == 0)
{
if (_variableDefinition.Expression is pol.SubjectAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding subject attribute designator: {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.ResourceAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding resource attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.ActionAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding action attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.EnvironmentAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding environment attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
}
// If the argument was not found and the attribute must be present this is
// a MissingAttribute situation so set the flag. Otherwise add the attribute
// to the processed arguments.
if (bag.BagSize == 0 && attrDes.MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute(attrDes);
_value = EvaluationValue.Indeterminate;
}
else
{
_value = new EvaluationValue(bag, bag.GetType(context));
}
return(_value);
}
else if (_variableDefinition.Expression is pol.AttributeSelectorElement)
{
// Resolve the XPath query using the EvaluationEngine public methods.
context.Trace("Attribute selector");
try
{
pol.AttributeSelectorElement attributeSelector = (pol.AttributeSelectorElement)_variableDefinition.Expression;
BagValue bag = EvaluationEngine.Resolve(context, attributeSelector);
if (bag.Elements.Count == 0 && attributeSelector.MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute(attributeSelector);
_value = EvaluationValue.Indeterminate;
}
else
{
_value = new EvaluationValue(bag, bag.GetType(context));
}
}
catch (EvaluationException e)
{
context.Trace("ERR: {0}", e.Message);
context.ProcessingError = true;
_value = EvaluationValue.Indeterminate;
}
return(_value);
}
throw new NotSupportedException("internal error");
}
finally
{
_isEvaluated = true;
context.RemoveIndent();
}
}
/// <summary>
/// Search for the attribute in the context target item using the attribute designator specified.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="attributeDesignator">The attribute designator instance.</param>
/// <param name="targetItem">The target item to search in.</param>
/// <returns>A bag value with the values of the attributes found.</returns>
public static BagValue FindAttribute( EvaluationContext context, pol.AttributeDesignatorBase attributeDesignator, ctx.TargetItemBase targetItem )
{
BagValue bag = new BagValue( GetDataType( attributeDesignator.DataType ) );
foreach( ctx.AttributeElement attribute in targetItem.Attributes )
{
if( attribute.Match( attributeDesignator ) )
{
context.Trace( "Adding target item attribute designator: {0}", attribute.ToString() );
bag.Add( attribute );
}
}
return bag;
}
/// <summary>
/// Solves the attribute designator in the context document using the attribute designator type
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="attributeDesignator">The attribute designator to resolve</param>
/// <returns>A bag value with the values found in the context document</returns>
public static BagValue Resolve( EvaluationContext context, pol.AttributeDesignatorBase attributeDesignator )
{
if( attributeDesignator is pol.SubjectAttributeDesignatorElement )
{
if( context.ContextDocument.Request != null && context.ContextDocument.Request.Subjects != null )
{
BagValue bag = new BagValue( GetDataType( attributeDesignator.DataType ) );
foreach( ctx.SubjectElement subject in context.ContextDocument.Request.Subjects )
{
if( ((pol.SubjectAttributeDesignatorElement)attributeDesignator).SubjectCategory == null ||
( (pol.SubjectAttributeDesignatorElement)attributeDesignator).SubjectCategory == subject.SubjectCategory )
{
foreach( ctx.AttributeElement attrib in FindAttribute( context, attributeDesignator, subject ).Elements )
{
bag.Add( attrib );
}
}
}
return bag;
}
}
else if( attributeDesignator is pol.ResourceAttributeDesignatorElement )
{
if( context.ContextDocument.Request != null && context.CurrentResource != null )
{
return FindAttribute( context, attributeDesignator, context.CurrentResource );
}
else
{
return BagValue.Empty;
}
}
else if( attributeDesignator is pol.ActionAttributeDesignatorElement )
{
if( context.ContextDocument.Request != null && context.ContextDocument.Request.Action != null )
{
return FindAttribute( context, attributeDesignator, context.ContextDocument.Request.Action );
}
else
{
return BagValue.Empty;
}
}
else if( attributeDesignator is pol.EnvironmentAttributeDesignatorElement )
{
if( context.ContextDocument.Request != null && context.ContextDocument.Request.Environment != null )
{
return FindAttribute( context, attributeDesignator, context.ContextDocument.Request.Environment );
}
else
{
return BagValue.Empty;
}
}
throw new EvaluationException( Resource.ResourceManager[ Resource.MessageKey.exc_invalid_attribute_designator ] );
}
/// <summary>
/// Resolves the AttributeSelector in the context document using the XPath sentence.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="attributeSelector">The attribute selector.</param>
/// <returns>A bag of values with the contents of the node.</returns>
public static BagValue Resolve( EvaluationContext context, pol.AttributeSelectorElement attributeSelector )
{
BagValue bagValue = new BagValue( GetDataType( attributeSelector.DataType ) );
ctx.ResourceContentElement content = (ctx.ResourceContentElement)context.CurrentResource.ResourceContent;
if( content != null )
{
XmlDocument doc = context.ContextDocument.XmlDocument;
if( context.ContextDocument.XmlNamespaceManager == null )
{
context.ContextDocument.AddNamespaces( context.PolicyDocument.Namespaces );
}
try
{
string xpath = attributeSelector.RequestContextPath;
XmlNodeList nodeList = doc.DocumentElement.SelectNodes( xpath, context.ContextDocument.XmlNamespaceManager );
if( nodeList != null )
{
foreach( XmlNode node in nodeList )
{
pol.AttributeValueElement ave =
new pol.AttributeValueElement(
attributeSelector.DataType,
node.InnerText,
attributeSelector.SchemaVersion );
bagValue.Add( ave );
}
}
}
catch( XPathException e )
{
context.Trace( Resource.TRACE_ERROR, e.Message );
bagValue = new BagValue( GetDataType( attributeSelector.DataType ) );
}
}
return bagValue;
}
/// <summary>
/// THe argument processing method resolves all the attribute designators, attribute
/// selectors. If there is an internal Apply it will be evaulated within this method.
/// </summary>
/// <remarks>All the processed arguments are converted into an IFunctionParameter instance
/// because this is the only value that can be used to call a function.</remarks>
/// <param name="context">The evaluation context instance.</param>
/// <param name="arguments">The arguments to process.</param>
/// <returns>A list of arguments ready to be used by a function.</returns>
private IFunctionParameterCollection ProcessArguments(EvaluationContext context, pol.IExpressionCollection arguments)
{
context.Trace("Processing arguments");
context.AddIndent();
// Create a list to return the processed values.
IFunctionParameterCollection processedArguments = new IFunctionParameterCollection();
// Iterate through the arguments, the IExpressionType is a mark interface
foreach (inf.IExpression arg in arguments)
{
if (arg is pol.ApplyElement)
{
context.Trace("Nested apply");
// There is a nested apply un this policy a new Apply will be created and also
// evaluated. It's return value will be used as the processed argument.
Apply _childApply = new Apply((pol.ApplyElement)arg);
// Evaluate the Apply
EvaluationValue retVal = _childApply.Evaluate(context);
context.TraceContextValues();
// If the results were Indeterminate the Indeterminate value will be placed in
// the processed arguments, later another method will validate the parameters
// and cancel the evaluation propperly.
if (!retVal.IsIndeterminate)
{
if (!context.IsMissingAttribute)
{
processedArguments.Add(retVal);
}
}
else
{
processedArguments.Add(retVal);
}
}
else if (arg is pol.FunctionElementReadWrite)
{
// Search for the function and place it in the processed arguments.
pol.FunctionElement functionId = new pol.FunctionElement(((pol.FunctionElementReadWrite)arg).FunctionId, ((pol.FunctionElementReadWrite)arg).SchemaVersion);
context.Trace("Function {0}", functionId.FunctionId);
inf.IFunction function = EvaluationEngine.GetFunction(functionId.FunctionId);
if (function == null)
{
context.Trace("ERR: function not found {0}", _applyBase.FunctionId);
context.ProcessingError = true;
processedArguments.Add(EvaluationValue.Indeterminate);
}
else
{
processedArguments.Add(function);
}
}
else if (arg is pol.VariableReferenceElement)
{
pol.VariableReferenceElement variableRef = arg as pol.VariableReferenceElement;
VariableDefinition variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition;
context.TraceContextValues();
if (!variableDef.IsEvaluated)
{
processedArguments.Add(variableDef.Evaluate(context));
}
else
{
processedArguments.Add(variableDef.Value);
}
}
else if (arg is pol.AttributeValueElementReadWrite)
{
// The AttributeValue does not need to be processed
context.Trace("Attribute value {0}", arg.ToString());
processedArguments.Add(new pol.AttributeValueElement(((pol.AttributeValueElementReadWrite)arg).DataType, ((pol.AttributeValueElementReadWrite)arg).Contents, ((pol.AttributeValueElementReadWrite)arg).SchemaVersion));
}
else if (arg is pol.AttributeDesignatorBase)
{
// Resolve the AttributeDesignator using the EvaluationEngine public methods.
context.Trace("Processing attribute designator: {0}", arg.ToString());
pol.AttributeDesignatorBase attrDes = (pol.AttributeDesignatorBase)arg;
BagValue bag = EvaluationEngine.Resolve(context, attrDes);
// If the attribute was not resolved by the EvaluationEngine search the
// attribute in the context document, also using the EvaluationEngine public
// methods.
if (bag.BagSize == 0)
{
if (arg is pol.SubjectAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding subject attribute designator: {0}", attrib.ToString());
bag.Add(attrib);
break;
}
}
else if (arg is pol.ResourceAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding resource attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (arg is pol.ActionAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding action attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (arg is pol.EnvironmentAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding environment attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
}
// If the argument was not found and the attribute must be present this is
// a MissingAttribute situation so set the flag. Otherwise add the attribute
// to the processed arguments.
if (bag.BagSize == 0 && attrDes.MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute(attrDes);
}
else
{
processedArguments.Add(bag);
}
}
else if (arg is pol.AttributeSelectorElement)
{
// Resolve the XPath query using the EvaluationEngine public methods.
context.Trace("Attribute selector");
try
{
BagValue bag = EvaluationEngine.Resolve(context, (pol.AttributeSelectorElement)arg);
if (bag.Elements.Count == 0 && ((pol.AttributeSelectorElement)arg).MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute((pol.AttributeReferenceBase)arg);
}
else
{
processedArguments.Add(bag);
}
}
catch (EvaluationException e)
{
context.Trace(Resource.TRACE_ERROR, e.Message);
processedArguments.Add(EvaluationValue.Indeterminate);
context.ProcessingError = true;
}
}
}
context.RemoveIndent();
return(processedArguments);
}