/// <summary> Protected constructor to allow for data structure population
/// *
/// </summary>
/// <param name="aId">The UID of the RuleResult
/// </param>
/// <param name="aFactory">The RuleFactory that create the RuleResult
/// </param>
/// <param name="aParams">A Map of the parameters
/// </param>
/// <param name="aStackLoc">The location on the stack of this RuleResult
/// </param>
/// <param name="aStep">The step within the rule
///
/// </param>
protected internal AbstractBRERuleMetaData(object aId, IBRERuleFactory aFactory, Hashtable aParams, int aStackLoc, object aStep)
{
id = aId;
factory = aFactory;
params_Renamed = aParams;
stackLoc = aStackLoc;
step = aStep;
}
/// <summary> Protected constructor to allow for data structure population
/// *
/// </summary>
/// <param name="aId">The UID of the RuleResult
/// </param>
/// <param name="aFactory">The RuleFactory that create the RuleResult
/// </param>
/// <param name="aParams">An IDictionary of the parameters
/// </param>
/// <param name="aStackLoc">The location on the stack of this RuleResult
/// </param>
/// <param name="aStep">The step within the rule
///
/// </param>
protected internal AbstractBRERuleMetaData(object aId, IBRERuleFactory aFactory, IDictionary aParams, int aStackLoc, object aStep)
{
id = aId;
factory = aFactory;
params_Renamed = aParams;
stackLoc = aStackLoc;
step = aStep;
}
/// <summary> This method preloads all defined factories with the XML document.
/// This is to catch any errors relating to class loading up front before we
/// get to the real document parsing and business logic.
/// <P>
/// This does not support graceful degradation on purpose.
/// If I can't get to a business rule, it should be understood
/// that technically, in the end, the rules fail.
/// </P>
/// </summary>
/// <param name="aNodeList">The List of Nodes to process
/// </param>
/// <returns> True if successful, False otherwise
///
/// </returns>
private bool LoadFactories(XPathNodeIterator aNodeList)
{
if (Logger.IsInferenceEngineInformation)
{
Logger.FlowEngineSource.TraceEvent(TraceEventType.Information, 0, "BRE Loading RuleFactories...");
}
if (aNodeList != null)
{
try
{
while (aNodeList.MoveNext())
{
string factory = aNodeList.Current.GetAttribute(RULE_ATTRS.FACTORY, String.Empty);
if (factory != String.Empty)
{
string id = aNodeList.Current.GetAttribute(RULE_ATTRS.ID, String.Empty);
if (Logger.IsFlowEngineVerbose)
{
Logger.FlowEngineSource.TraceEvent(TraceEventType.Verbose, 0, "Found Factory: " + factory + " Id: " + id);
}
if (Logger.IsFlowEngineVerbose)
{
Logger.FlowEngineSource.TraceEvent(TraceEventType.Verbose, 0, "Loading Factory: " + id);
}
object tmpClass = Reflection.ClassNew(factory, null);
if (tmpClass is IBRERuleFactory)
{
IBRERuleFactory brf = (IBRERuleFactory)tmpClass;
ruleContext.SetFactory(id, brf);
if (Logger.IsFlowEngineVerbose)
{
Logger.FlowEngineSource.TraceEvent(TraceEventType.Verbose, 0, "BRE RuleFactory " + id + " loaded and added to RuleContext");
}
}
else
{
throw new BREException("Specified Rule Factory " + factory + " with id " + id + " not of type IBRERuleFactory");
}
}
}
return(true);
}
catch (System.Exception e)
{
if (Logger.IsFlowEngineCritical)
{
Logger.FlowEngineSource.TraceData(TraceEventType.Critical, 0, e);
}
}
}
return(false);
}
/// <summary> Sets a RuleFactory
/// *
/// </summary>
/// <param name="aId">The UID of the RuleFactory
/// </param>
/// <param name="aFactory">The Factory
///
/// </param>
public virtual void SetFactory(object aId, IBRERuleFactory aFactory)
{
if (factories != null)
{
if (factories.Contains(aId))
{
factories.Remove(aId);
}
factories.Add(aId, aFactory);
}
}
/// <summary> This method preloads all defined factories with the XML document.
/// This is to catch any errors relating to class loading up front before we
/// get to the real document parsing and business logic.
/// <P>
/// This does not support graceful degradation on purpose.
/// If I can't get to a business rule, it should be understood
/// that technically, in the end, the rules fail.
/// </P>
/// </summary>
/// <param name="aNodeList">The List of Nodes to process
/// </param>
/// <returns> True if successful, False otherwise
///
/// </returns>
private bool LoadFactories(XPathNodeIterator aNodeList)
{
DispatchLog("BRE Loading RuleFactories...", LogEventImpl.INFO);
if (aNodeList != null)
{
try
{
while (aNodeList.MoveNext())
{
string factory = aNodeList.Current.GetAttribute(RULE_ATTRS.FACTORY, String.Empty);
if (factory != String.Empty)
{
string id = aNodeList.Current.GetAttribute(RULE_ATTRS.ID, String.Empty);
DispatchLog("Found Factory: " + factory + " Id: " + id, LogEventImpl.DEBUG);
DispatchLog("Loading Factory: " + id, LogEventImpl.DEBUG);
object tmpClass = Assembly.GetExecutingAssembly().CreateInstance(factory);
if (tmpClass is IBRERuleFactory)
{
IBRERuleFactory brf = (IBRERuleFactory)tmpClass;
ruleContext.SetFactory(id, brf);
DispatchLog("BRE RuleFactory " + id + " loaded and added to RuleContext.", LogEventImpl.DEBUG);
}
else
{
throw new System.InvalidCastException("Specified Rule Factory " + factory + " with id " + id + " not of type BRERuleFactory");
}
}
}
return(true);
}
catch (System.Exception e)
{
DispatchException(e, ExceptionEventImpl.FATAL);
}
}
return(false);
}
/// <summary> Creates a new instance of the object
/// <P>
/// This constructor makes a call to a protected constructor
/// within AbstractBRERuleContext. This is another reason
/// why this class in final, because this technically breaks
/// encapsulation. For more info see:</P><P>
/// <I>Effective Java</I> (first printing) by Joshua Bloch.
/// Item 14, pg. 71
/// </P>
/// *
/// </summary>
/// <param name="aId">The UID of the RuleResult
/// </param>
/// <param name="aFactory">The RuleFactory that create the RuleResult
/// </param>
/// <param name="aParams">A Map of the parameters
/// </param>
/// <param name="aStackLoc">The location on the stack of this RuleResult
/// </param>
/// <param name="aStep">The step within the rule
///
/// </param>
public BRERuleMetaDataImpl(object aId, IBRERuleFactory aFactory, Hashtable aParams, int aStackLoc, object aStep) : base(aId, aFactory, aParams, aStackLoc, aStep)
{
}
/// <summary> This methods processes the Rule nodes that may exist in the XML.
/// <P>
/// It executes as follows (this may not look so straightforward in the code...):
/// <OL>
/// <LI>Executes Factories executeRule()</LI>
/// <LI>takes the result and puts it into a RuleResult object</LI>
/// <LI>listeners.dispatches an error if it could not find the factory
/// (See docs in code)</LI>
/// <LI>Catches any exceptions from the executeRule() and makes it a
/// RuleResult so it can be handled gracefully</LI>
/// <LI>Adds the RuleResult to the CallStack</LI>
/// <LI>listeners.dispatched the RuleResult to any listeners</LI>
/// <LI>Adds the RuleResult to the RuleContext</LI>
/// </OL>
/// </P>
/// </summary>
/// <param name="id">The ID of the Rule
/// </param>
/// <param name="step">The current Step
/// </param>
/// <param name="aMap">The Parameters map
/// </param>
private void DoRule(object id, object step, Hashtable aMap)
{
int nextStackLoc = ruleContext.CallStack.Count;
IBRERuleResult ruleResult = null;
try
{
IBRERuleFactory factory = ruleContext.GetFactory(id);
/*
* I have to check for null because if the RuleContext
* was passed in, an external reference exists and can be
* modified at any time
*/
if (factory != null)
{
//setup metadata
IBRERuleMetaData metaData = new BRERuleMetaDataImpl(id, factory, aMap, nextStackLoc, step);
object result = factory.ExecuteRule(ruleContext, aMap, step);
ruleResult = new BRERuleResultImpl(metaData, result);
}
else
{
/*
* A WARN version of this error can occur when the
* Factories are loaded. But if the developer passed in
* a RuleContext, they can place the Factory into the
* RuleContext still. If we get to this point it is now a full
* blown error because if it is not in the RuleContext at this point and
* it to late and can cause issues
*/
if (Logger.IsFlowEngineError)
{
Logger.FlowEngineSource.TraceData(TraceEventType.Error, 0, new BREException("Factory Id " + id + " defined, but not found in RuleContext"));
}
}
}
// This can occur internally in the RuleContext
catch (System.InvalidCastException cce)
{
if (Logger.IsFlowEngineCritical)
{
Logger.FlowEngineSource.TraceData(TraceEventType.Critical, 0, new BREException("Object in RuleContext not of correct type. " + cce.ToString()));
}
}
// Catch unknown exceptions in the factory itself
catch (System.Exception e)
{
if (Logger.IsFlowEngineError)
{
Logger.FlowEngineSource.TraceData(TraceEventType.Error, 0, new BREException("Error when processing RuleFactory id: " + id, e));
}
/*
* Set the RuleResult to an exception so I can test for it in the If
* Hey, technically it IS what it returned ;)
* The factory can return null here, but that could have caused the
* exception anyway.....
*/
IBRERuleMetaData metaData = new BRERuleMetaDataImpl(id, ruleContext.GetFactory(id), aMap, nextStackLoc, step);
ruleResult = new BRERuleResultImpl(metaData, e);
}
ruleContext.CallStack.Push(ruleResult);
// call listeners
DispatchRuleResult(ruleResult);
ruleContext.SetResult(id, ruleResult);
}
/// <summary> Sets a RuleFactory
/// *
/// </summary>
/// <param name="aId">The UID of the RuleFactory
/// </param>
/// <param name="aFactory">The Factory
///
/// </param>
public virtual void SetFactory(object aId, IBRERuleFactory aFactory)
{
if (factories != null) {
if (factories.Contains(aId)) factories.Remove(aId);
factories.Add(aId, aFactory);
}
}
/// <summary> Creates a new instance of the object
/// <P>
/// This constructor makes a call to a protected constructor
/// within AbstractBRERuleContext. This is another reason
/// why this class in final, because this technically breaks
/// encapsulation. For more info see:</P><P>
/// <I>Effective Java</I> (first printing) by Joshua Bloch.
/// Item 14, pg. 71
/// </P>
/// *
/// </summary>
/// <param name="aId">The UID of the RuleResult
/// </param>
/// <param name="aFactory">The RuleFactory that create the RuleResult
/// </param>
/// <param name="aParams">A Map of the parameters
/// </param>
/// <param name="aStackLoc">The location on the stack of this RuleResult
/// </param>
/// <param name="aStep">The step within the rule
///
/// </param>
public BRERuleMetaDataImpl(object aId, IBRERuleFactory aFactory, Hashtable aParams, int aStackLoc, object aStep)
: base(aId, aFactory, aParams, aStackLoc, aStep)
{
}
/// <summary> Sets a RuleFactory
/// *
/// </summary>
/// <param name="aId">The UID of the RuleFactory
/// </param>
/// <param name="aFactory">The Factory
///
/// </param>
public virtual void SetFactory(object aId, IBRERuleFactory aFactory)
{
if (factories != null) {
factories[aId] = aFactory;
}
}