/// <summary>
/// Evaluates the rule contents.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <returns>A decission for this evalauation.</returns>
public Decision Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
context.Trace("Evaluating rule: {0}", _rule.Description);
context.AddIndent();
context.CurrentRule = this;
try
{
// Validate the Target element
TargetEvaluationValue targetEvaluation = Match(context);
// If the target matches the conditions ar evaluated
EvaluationValue conditionEvaluation = EvaluationValue.True;
if (_rule.HasCondition)
{
// Evaluate the condition
conditionEvaluation = _condition.Evaluate(context);
}
else
{
context.Trace("Rule does not have a condition");
}
// Decite the final rule evaluation value
if (targetEvaluation == TargetEvaluationValue.Indeterminate || conditionEvaluation.IsIndeterminate)
{
_evaluationValue = Decision.Indeterminate;
}
else if (targetEvaluation == TargetEvaluationValue.Match && conditionEvaluation.BoolValue)
{
_evaluationValue = ((_rule.Effect == pol.Effect.Permit) ? Decision.Permit : Decision.Deny);
}
else if ((targetEvaluation == TargetEvaluationValue.NoMatch) ||
(targetEvaluation == TargetEvaluationValue.Match && !conditionEvaluation.BoolValue))
{
_evaluationValue = Decision.NotApplicable;
}
// Return the value
context.Trace("Rule: {0}", _evaluationValue);
return(_evaluationValue);
}
finally
{
context.RemoveIndent();
context.CurrentRule = null;
}
}
/// <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 );
EvaluationValue value = new EvaluationValue( args[1], args[1].GetType( context ) );
foreach( object par in args[2].Elements )
{
EvaluationValue retVal = function.Evaluate( context, value, new EvaluationValue( par, args[2].GetType( context ) ) );
if( !retVal.BoolValue )
{
return retVal;
}
}
return EvaluationValue.True;
}
/// <summary>
/// Main evaluation method which is divided in two phases: Argument processing and
/// Function evaluation.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <returns>The result of the evaluation in an EvaluationValue instance.</returns>
public virtual EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
// Validate the function exists
context.Trace("Calling function: {0}", _applyBase.FunctionId);
inf.IFunction function = EvaluationEngine.GetFunction(_applyBase.FunctionId);
if (function == null)
{
context.Trace("ERR: function not found {0}", _applyBase.FunctionId);
context.ProcessingError = true;
return(EvaluationValue.Indeterminate);
}
// Process the arguments.
IFunctionParameterCollection arguments = ProcessArguments(context, new pol.IExpressionCollection((pol.IExpressionReadWriteCollection)_applyBase.Arguments));
// Call the function with the arguments processed.
EvaluationValue returnValue = EvaluationEngine.EvaluateFunction(context, function, arguments.ToArray());
return(returnValue);
}
/// <summary>
/// This method overrides the ApplyBase method in order to provide extra validations
/// required in the condition evaluation, for example the final return value should be a
/// boolean value.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <returns>The EvaluationValue with the results of the condition evaluation.</returns>
public override EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
EvaluationValue _evaluationValue = null;
context.Trace("Evaluating condition...");
context.AddIndent();
try
{
// Get the function instance
inf.IFunction function = EvaluationEngine.GetFunction(ApplyDefinition.FunctionId);
if (function == null)
{
context.Trace("ERR: function not found {0}", ApplyDefinition.FunctionId);
context.ProcessingError = true;
return(EvaluationValue.Indeterminate);
}
// Validates the function return value
if (function.Returns == null)
{
context.Trace("The function '{0}' does not defines it's return value", ApplyDefinition.FunctionId);
_evaluationValue = EvaluationValue.Indeterminate;
context.ProcessingError = true;
}
else if (function.Returns != DataTypeDescriptor.Boolean)
{
context.Trace("Function does not return Boolean a value");
_evaluationValue = EvaluationValue.Indeterminate;
context.ProcessingError = true;
}
else
{
// Call the ApplyBase method to perform the evaluation.
_evaluationValue = base.Evaluate(context);
}
// Validate the results of the evaluation
if (_evaluationValue.IsIndeterminate)
{
context.Trace("condition evaluated into {0}", _evaluationValue.ToString());
return(_evaluationValue);
}
if (!(_evaluationValue.Value is bool))
{
context.Trace("condition evaluated into {0}", _evaluationValue.ToString());
return(EvaluationValue.Indeterminate);
}
if (_evaluationValue.BoolValue)
{
context.Trace("condition evaluated into {0}", _evaluationValue.ToString());
return(EvaluationValue.True);
}
else
{
// If the evaluation was false, validate if there was a missin attribute during
// evaluation and return an Indeterminate, otherwise return the False value.
if (context.IsMissingAttribute)
{
context.Trace("condition evaluated into {0}", _evaluationValue.ToString());
return(EvaluationValue.Indeterminate);
}
else
{
context.Trace("condition evaluated into {0}", _evaluationValue.ToString());
return(EvaluationValue.False);
}
}
}
finally
{
context.TraceContextValues();
context.RemoveIndent();
context.Trace("Condition: {0}", _evaluationValue.ToString());
}
}
/// <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>
/// 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>
/// 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);
}
/// <summary>
/// This method overrides the ApplyBase method in order to provide extra validations
/// required in the condition evaluation, for example the final return value should be a
/// boolean value.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <returns>The EvaluationValue with the results of the condition evaluation.</returns>
public override EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
context.Trace("Evaluating condition");
context.AddIndent();
try
{
// Iterate through the arguments, the IExpressionType is a mark interface
foreach (inf.IExpression arg in ApplyDefinition.Arguments)
{
if (arg 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)arg);
// Evaluate the Apply
EvaluationValue retVal = _childApply.Evaluate(context);
return(retVal);
}
else if (arg is pol.FunctionElementReadWrite)
{
throw new NotImplementedException("FunctionElement"); //TODO:
}
else if (arg is pol.VariableReferenceElement)
{
pol.VariableReferenceElement variableRef = arg as pol.VariableReferenceElement;
VariableDefinition variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition;
if (!variableDef.IsEvaluated)
{
return(variableDef.Evaluate(context));
}
else
{
return(variableDef.Value);
}
}
else if (arg is pol.AttributeValueElementReadWrite)
{
// The AttributeValue does not need to be processed
context.Trace("Attribute value {0}", arg.ToString());
pol.AttributeValueElement attributeValue = new pol.AttributeValueElement(((pol.AttributeValueElementReadWrite)arg).DataType, ((pol.AttributeValueElementReadWrite)arg).Contents, ((pol.AttributeValueElementReadWrite)arg).SchemaVersion);
return(new EvaluationValue(
attributeValue.GetTypedValue(attributeValue.GetType(context), 0),
attributeValue.GetType(context)));
}
else if (arg is pol.AttributeDesignatorBase)
{
// Returning an empty bag, since the condition is not supposed to work with a bag
context.Trace("Processing attribute designator: {0}", arg.ToString());
pol.AttributeDesignatorBase attrDes = (pol.AttributeDesignatorBase)arg;
BagValue bag = new BagValue(EvaluationEngine.GetDataType(attrDes.DataType));
return(new EvaluationValue(bag, bag.GetType(context)));
}
else if (arg is pol.AttributeSelectorElement)
{
// Returning an empty bag, since the condition is not supposed to work with a bag
context.Trace("Attribute selector");
pol.AttributeSelectorElement attrSel = (pol.AttributeSelectorElement)arg;
BagValue bag = new BagValue(EvaluationEngine.GetDataType(attrSel.DataType));
return(new EvaluationValue(bag, bag.GetType(context)));
}
}
throw new NotSupportedException("internal error");
}
finally
{
context.TraceContextValues();
context.RemoveIndent();
}
}
/// <summary>
/// Evaluates the target items and return wether the target applies to the context or not.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <param name="targetItem">The target item in the context document.</param>
/// <returns></returns>
public TargetEvaluationValue Evaluate(EvaluationContext context, ctx.TargetItemBase targetItem)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (_targetItems.IsAny)
{
context.Trace("IsAny");
return(TargetEvaluationValue.Match);
}
_evaluationValue = TargetEvaluationValue.NoMatch;
//Match TargetItem
foreach (pol.TargetItemBase polItem in _targetItems.ItemsList)
{
foreach (pol.TargetMatchBase match in polItem.Match)
{
_evaluationValue = TargetEvaluationValue.NoMatch;
context.Trace("Using function: {0}", match.MatchId);
inf.IFunction matchFunction = EvaluationEngine.GetFunction(match.MatchId);
if (matchFunction == null)
{
context.Trace("ERR: function not found {0}", match.MatchId);
context.ProcessingError = true;
return(TargetEvaluationValue.Indeterminate);
}
if (matchFunction.Returns == null)
{
// Validates the function return value
context.Trace("ERR: The function '{0}' does not defines it's return value", match.MatchId);
context.ProcessingError = true;
return(TargetEvaluationValue.Indeterminate);
}
if (matchFunction.Returns != DataTypeDescriptor.Boolean)
{
context.Trace("ERR: Function does not return Boolean a value");
context.ProcessingError = true;
return(TargetEvaluationValue.Indeterminate);
}
ctx.AttributeElement attribute = EvaluationEngine.Resolve(context, match, targetItem);
if (attribute != null)
{
context.Trace("Attribute found, evaluating match function");
try
{
EvaluationValue returnValue = EvaluationEngine.EvaluateFunction(context, matchFunction, match.AttributeValue, attribute);
_evaluationValue = returnValue.BoolValue ? TargetEvaluationValue.Match : TargetEvaluationValue.NoMatch;
}
catch (EvaluationException e)
{
context.Trace(Resource.TRACE_ERROR, e.Message);
_evaluationValue = TargetEvaluationValue.Indeterminate;
}
}
// Validate MustBePresent
if (match.AttributeReference.MustBePresent)
{
if (context.IsMissingAttribute)
{
context.Trace("Attribute not found and must be present");
_evaluationValue = TargetEvaluationValue.Indeterminate;
}
}
// Do not iterate if the value was found
if (_evaluationValue != TargetEvaluationValue.Match)
{
break;
}
}
// Do not iterate if the value was found
if (_evaluationValue == TargetEvaluationValue.Match)
{
return(_evaluationValue);
}
}
return(_evaluationValue);
}