/// <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 (IExpression arg in ApplyDefinition.Arguments) { if (arg is 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. var childApply = new Apply((ApplyElement)arg); // Evaluate the Apply EvaluationValue retVal = childApply.Evaluate(context); return(retVal); } else if (arg is FunctionElementReadWrite) { throw new NotImplementedException("FunctionElement"); //TODO: } else if (arg is VariableReferenceElement) { var variableRef = arg as VariableReferenceElement; var variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition; Debug.Assert(variableDef != null, "variableDef != null"); if (!variableDef.IsEvaluated) { return(variableDef.Evaluate(context)); } else { return(variableDef.Value); } } else if (arg is AttributeValueElementReadWrite) { // The AttributeValue does not need to be processed context.Trace("Attribute value {0}", arg.ToString()); var attributeValue = new AttributeValueElement(((AttributeValueElementReadWrite)arg).DataType, ((AttributeValueElementReadWrite)arg).Contents, ((AttributeValueElementReadWrite)arg).SchemaVersion); return(new EvaluationValue( attributeValue.GetTypedValue(attributeValue.GetType(context), 0), attributeValue.GetType(context))); } else if (arg is AttributeDesignatorBase) { // Returning an empty bag, since the condition is not supposed to work with a bag context.Trace("Processing attribute designator: {0}", arg.ToString()); var attrDes = (AttributeDesignatorBase)arg; var bag = new BagValue(EvaluationEngine.GetDataType(attrDes.DataType)); return(new EvaluationValue(bag, bag.GetType(context))); } else if (arg is AttributeSelectorElement) { // Returning an empty bag, since the condition is not supposed to work with a bag context.Trace("Attribute selector"); var attrSel = (AttributeSelectorElement)arg; var 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 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 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((ApplyElement)_variableDefinition.Expression); // Evaluate the Apply _value = childApply.Evaluate(context); context.TraceContextValues(); return(_value); } else if (_variableDefinition.Expression is FunctionElement) { throw new NotImplementedException("FunctionElement"); //TODO: } else if (_variableDefinition.Expression is VariableReferenceElement) { var variableRef = _variableDefinition.Expression as VariableReferenceElement; var 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 AttributeValueElementReadWrite) { // The AttributeValue does not need to be processed context.Trace("Attribute value {0}", _variableDefinition.Expression.ToString()); var att = (AttributeValueElementReadWrite)_variableDefinition.Expression; var attributeValue = new 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 AttributeDesignatorBase) { // Resolve the AttributeDesignator using the EvaluationEngine public methods. context.Trace("Processing attribute designator: {0}", _variableDefinition.Expression.ToString()); var attrDes = (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 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 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 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 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 AttributeSelectorElement) { // Resolve the XPath query using the EvaluationEngine public methods. context.Trace("Attribute selector"); try { var attributeSelector = (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> /// 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 (IExpression arg in ApplyDefinition.Arguments) { if (arg is 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. var childApply = new Apply((ApplyElement)arg); // Evaluate the Apply EvaluationValue retVal = childApply.Evaluate(context); return retVal; } else if (arg is FunctionElementReadWrite) { throw new NotImplementedException("FunctionElement"); //TODO: } else if (arg is VariableReferenceElement) { var variableRef = arg as VariableReferenceElement; var variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition; Debug.Assert(variableDef != null, "variableDef != null"); if (!variableDef.IsEvaluated) { return variableDef.Evaluate(context); } else { return variableDef.Value; } } else if (arg is AttributeValueElementReadWrite) { // The AttributeValue does not need to be processed context.Trace("Attribute value {0}", arg.ToString()); var attributeValue = new AttributeValueElement(((AttributeValueElementReadWrite)arg).DataType, ((AttributeValueElementReadWrite)arg).Contents, ((AttributeValueElementReadWrite)arg).SchemaVersion); return new EvaluationValue( attributeValue.GetTypedValue(attributeValue.GetType(context), 0), attributeValue.GetType(context)); } else if (arg is AttributeDesignatorBase) { // Returning an empty bag, since the condition is not supposed to work with a bag context.Trace("Processing attribute designator: {0}", arg.ToString()); var attrDes = (AttributeDesignatorBase)arg; var bag = new BagValue(EvaluationEngine.GetDataType(attrDes.DataType)); return new EvaluationValue(bag, bag.GetType(context)); } else if (arg is AttributeSelectorElement) { // Returning an empty bag, since the condition is not supposed to work with a bag context.Trace("Attribute selector"); var attrSel = (AttributeSelectorElement)arg; var bag = new BagValue(EvaluationEngine.GetDataType(attrSel.DataType)); return new EvaluationValue(bag, bag.GetType(context)); } } throw new NotSupportedException("internal error"); } finally { context.TraceContextValues(); context.RemoveIndent(); } }