/// <summary>
/// Navigates this node (and recusively into child nodes) for a match to the path passed as an argument
/// whilst processing the referenced request
/// </summary>
/// <param name="path">The normalized path derived from the user's input</param>
/// <param name="query">The query that this search is for</param>
/// <param name="request">An encapsulation of the request from the user</param>
/// <param name="matchstate">The part of the input path the node represents</param>
/// <param name="wildcard">The contents of the user input absorbed by the AIML wildcards "_" and "*"</param>
/// <returns>The template to process to generate the output</returns>
public string evaluate(string path, SubQuery query, Request request, MatchState matchstate, StringBuilder wildcard)
{
// check for timeout
if (request.StartedOn.AddMilliseconds(request.bot.TimeOut) < DateTime.Now)
{
request.bot.writeToLog("WARNING! Request timeout. User: "******" raw input: \"" + request.rawInput + "\"");
request.hasTimedOut = true;
return(string.Empty);
}
// so we still have time!
path = path.Trim();
// check if this is the end of a branch in the GraphMaster
// return the cCategory for this node
if (this.children.Count == 0)
{
if (path.Length > 0)
{
// if we get here it means that there is a wildcard in the user input part of the
// path.
this.storeWildCard(path, wildcard);
}
return(this.template);
}
// if we've matched all the words in the input sentence and this is the end
// of the line then return the cCategory for this node
if (path.Length == 0)
{
return(this.template);
}
// otherwise split the input into it's component words
string[] splitPath = path.Split(" \r\n\t".ToCharArray());
// get the first word of the sentence
string firstWord = Normalize.MakeCaseInsensitive.TransformInput(splitPath[0]);
// and concatenate the rest of the input into a new path for child nodes
string newPath = path.Substring(firstWord.Length, path.Length - firstWord.Length);
// first option is to see if this node has a child denoted by the "_"
// wildcard. "_" comes first in precedence in the AIML alphabet
if (this.children.ContainsKey("_"))
{
Node childNode = (Node)this.children["_"];
// add the next word to the wildcard match
StringBuilder newWildcard = new StringBuilder();
this.storeWildCard(splitPath[0], newWildcard);
// move down into the identified branch of the GraphMaster structure
string result = childNode.evaluate(newPath, query, request, matchstate, newWildcard);
// and if we get a result from the branch process the wildcard matches and return
// the result
if (result.Length > 0)
{
if (newWildcard.Length > 0)
{
// capture and push the star content appropriate to the current matchstate
switch (matchstate)
{
case MatchState.UserInput:
query.InputStar.Add(newWildcard.ToString());
// added due to this match being the end of the line
newWildcard.Remove(0, newWildcard.Length);
break;
case MatchState.That:
query.ThatStar.Add(newWildcard.ToString());
break;
case MatchState.Topic:
query.TopicStar.Add(newWildcard.ToString());
break;
}
}
return(result);
}
}
// second option - the nodemapper may have contained a "_" child, but led to no match
// or it didn't contain a "_" child at all. So get the child nodemapper from this
// nodemapper that matches the first word of the input sentence.
if (this.children.ContainsKey(firstWord))
{
// process the matchstate - this might not make sense but the matchstate is working
// with a "backwards" path: "topic <topic> that <that> user input"
// the "classic" path looks like this: "user input <that> that <topic> topic"
// but having it backwards is more efficient for searching purposes
MatchState newMatchstate = matchstate;
if (firstWord == "<THAT>")
{
newMatchstate = MatchState.That;
}
else if (firstWord == "<TOPIC>")
{
newMatchstate = MatchState.Topic;
}
Node childNode = (Node)this.children[firstWord];
// move down into the identified branch of the GraphMaster structure using the new
// matchstate
StringBuilder newWildcard = new StringBuilder();
string result = childNode.evaluate(newPath, query, request, newMatchstate, newWildcard);
// and if we get a result from the child return it
if (result.Length > 0)
{
if (newWildcard.Length > 0)
{
// capture and push the star content appropriate to the matchstate if it exists
// and then clear it for subsequent wildcards
switch (matchstate)
{
case MatchState.UserInput:
query.InputStar.Add(newWildcard.ToString());
newWildcard.Remove(0, newWildcard.Length);
break;
case MatchState.That:
query.ThatStar.Add(newWildcard.ToString());
newWildcard.Remove(0, newWildcard.Length);
break;
case MatchState.Topic:
query.TopicStar.Add(newWildcard.ToString());
newWildcard.Remove(0, newWildcard.Length);
break;
}
}
return(result);
}
}
// third option - the input part of the path might have been matched so far but hasn't
// returned a match, so check to see it contains the "*" wildcard. "*" comes last in
// precedence in the AIML alphabet.
if (this.children.ContainsKey("*"))
{
// o.k. look for the path in the child node denoted by "*"
Node childNode = (Node)this.children["*"];
// add the next word to the wildcard match
StringBuilder newWildcard = new StringBuilder();
this.storeWildCard(splitPath[0], newWildcard);
string result = childNode.evaluate(newPath, query, request, matchstate, newWildcard);
// and if we get a result from the branch process and return it
if (result.Length > 0)
{
if (newWildcard.Length > 0)
{
// capture and push the star content appropriate to the current matchstate
switch (matchstate)
{
case MatchState.UserInput:
query.InputStar.Add(newWildcard.ToString());
// added due to this match being the end of the line
newWildcard.Remove(0, newWildcard.Length);
break;
case MatchState.That:
query.ThatStar.Add(newWildcard.ToString());
break;
case MatchState.Topic:
query.TopicStar.Add(newWildcard.ToString());
break;
}
}
return(result);
}
}
// o.k. if the nodemapper has failed to match at all: the input contains neither
// a "_", the sFirstWord text, or "*" as a means of denoting a child node. However,
// if this node is itself representing a wildcard then the search continues to be
// valid if we proceed with the tail.
if ((this.word == "_") || (this.word == "*"))
{
this.storeWildCard(splitPath[0], wildcard);
return(this.evaluate(newPath, query, request, matchstate, wildcard));
}
// If we get here then we're at a dead end so return an empty string. Hopefully, if the
// AIML files have been set up to include a "* <that> * <topic> *" catch-all this
// state won't be reached. Remember to empty the surplus to requirements wildcard matches
wildcard = new StringBuilder();
return(string.Empty);
}
