/// <summary>
/// Generates a knowledge structure (KStructure object) from a ranked order (RankOrder object) by applying Rule 1.
/// </summary>
///
/// <param name="rankOrder">RankOrder object that is used to generate a knowledge structure.</param>
///
/// <returns>KStructure object, or null if error occured.</returns>
public KStructure createKStructure(RankOrder rankOrder)
{
// Implements Rule 1: Given a set GR of problems with a rank R and a set G<R of problems of lower ranks,
// a union of any subset of GR with G<R is a knowledge state.
// [SC] make sure the rankOrder object is not null
if (rankOrder == null)
{
Log(Severity.Error, "createKStructure: Null object is passed as RankOrder parameter. Returning null.");
return(null);
}
// [SC] make sure there is at least one rank in the rank order
if (rankOrder.getRankCount() == 0)
{
Log(Severity.Error, "createKStructure: rank order has no ranks. Returning null.");
return(null);
}
// [SC] make sure the ranks are sorted in an ascending order
rankOrder.sortAscending();
// [SC] creating knowledge states
List <KState> allStates = new List <KState>();
List <PCategory> prevCategories = new List <PCategory>();
foreach (Rank rank in rankOrder.getRanks())
{
// [SC] getting all unique subsets of categories in this rank
List <List <PCategory> > subsets = rank.getSubsets();
// [SC] for each subset, create a knowledge state by combining with all categories of lower ranks
foreach (List <PCategory> subset in subsets)
{
KState state = new KState();
foreach (PCategory category in prevCategories)
{
state.addCategory(category);
}
foreach (PCategory category in subset)
{
state.addCategory(category);
}
allStates.Add(state);
}
prevCategories.AddRange(rank.getCategories());
}
// [SC] sort states by their sizes in an ascending order
allStates.Sort((stateOne, stateTwo) => stateOne.getCategoryCount().CompareTo(stateTwo.getCategoryCount()));
// [SC] creating an empty knowledge structure object
KStructure ks = new KStructure(rankOrder);
// [SC] creating 0th rank with an empty root state
int rankIndex = 0;
int stateCounter = 0; // [SC] used to generate an ID for each state
KSRank prevRank = null;
KSRank currRank = new KSRank(rankIndex); // [SC] the root rank will automatically add an empty root state
ks.addRank(currRank);
// [SC] adding all states in respective ranks
foreach (KState state in allStates)
{
if (state.getCategoryCount() > rankIndex)
{
stateCounter = 0;
prevRank = currRank;
currRank = new KSRank(++rankIndex);
ks.addRank(currRank);
}
if (currRank.addState(state))
{
state.Id = KSGenerator.getStateID(rankIndex, ++stateCounter);
foreach (KState prevState in prevRank.getStates())
{
if (prevState.isSubsetOf(state))
{
prevState.addNextState(state);
state.addPrevState(prevState);
}
}
}
}
return(ks);
}
/// <summary>
/// creates an XML document object from a given KStructure object
/// </summary>
///
/// <param name="kStructure">KStructure object with a rank order and knowledge structure</param>
///
/// <returns>XmlDocument object</returns>
public XDocument createXml(KStructure kStructure)
{
// [SC] verifying that KStructure object is not null
if (kStructure == null)
{
Log(Severity.Error, "Unable to transform knowledge structure into XML format. kStructure parameter is null. Returning null.");
return(null);
}
// [SC] create xml document object
XDocument doc = new XDocument();
// [SC] add xml declaration to the document
doc.Declaration = new XDeclaration("1.0", "UTF-8", "yes");
// [SC] add a root element 'TwoA' and declare namespace attributes
XElement twoAElem = new XElement(XMLFactory.TWOA_ELEM
, new XAttribute(XMLFactory.XMLNS_ATTR, XMLFactory.twoa)
, new XAttribute(XMLFactory.XSD_ATTR, XMLFactory.xsd)
);
doc.Add(twoAElem);
// [SC] create a list of categories and a rank order
if (kStructure.hasRankOrder())
{
RankOrder rankOrder = kStructure.rankOrder;
rankOrder.sortAscending();
// [SC] add 'TwoA/PCategories' list element
XElement pcatsElem = new XElement(XMLFactory.PCATS_ELEM);
twoAElem.Add(pcatsElem);
// [SC] add 'TwoA/RankOrder' element
XElement rankOrderElem = new XElement(XMLFactory.RANKORDER_ELEM);
twoAElem.Add(rankOrderElem);
// [SC] add 'TwoA/RankOrder/Params' list element
XElement rankParamsElem = new XElement(XMLFactory.PARAMS_ELEM);
rankOrderElem.Add(rankParamsElem);
// [SC] add 'TwoA/RankOrder/Params.Threshold' element
XElement thresholdElem = new XElement(XMLFactory.THRESHOLD_ELEM);
rankParamsElem.Add(thresholdElem);
thresholdElem.SetValue("" + rankOrder.Threshold);
// [SC] create 'TwoA/RankOrder/Ranks' list element
XElement ranksElem = new XElement(XMLFactory.RANKS_ELEM);
rankOrderElem.Add(ranksElem);
// [SC] iterate through ranks and create correspoinding XML elements
for (int rankCounter = 0; rankCounter < rankOrder.getRankCount(); rankCounter++)
{
Rank rank = rankOrder.getRankAt(rankCounter);
// [SC] add 'TwoA/RankOrder/Ranks/Rank' element
XElement rankElem = new XElement(XMLFactory.RANK_ELEM);
ranksElem.Add(rankElem);
// [SC] add 'TwoA/RankOrder/Ranks/Rank@Index' attribute to the 'Rank' element
XAttribute indexAttr = new XAttribute(XMLFactory.INDEX_ATTR, "" + rank.RankIndex);
rankElem.Add(indexAttr);
// [SC] interate through categories in the rank and create corresponding XML element and reference to it
for (int catCounter = 0; catCounter < rank.getCategoryCount(); catCounter++)
{
PCategory pcat = rank.getCategoryAt(catCounter);
// [SC] add 'TwoA/PCategories/PCategory' element with 'xsd:id' attribute
XElement pcatElem = new XElement(XMLFactory.PCAT_ELEM);
pcatsElem.Add(pcatElem);
// [SC] add 'TwoA/PCategories/PCategory@xsd:id' attribute
XAttribute idAttr = new XAttribute(XMLFactory.ID_ATTR, "" + pcat.Id);
pcatElem.Add(idAttr);
// [SC] add 'TwoA/PCategories/PCategory/Rating' element
XElement ratingElem = new XElement(XMLFactory.RATING_ELEM);
pcatElem.Add(ratingElem);
ratingElem.SetValue("" + pcat.Rating);
// [SC] add 'TwoA/RankOrder/Ranks/Rank/PCategory' element with 'xsd:idref' attribute
XElement pcatRefElem = new XElement(XMLFactory.PCAT_ELEM);
rankElem.Add(pcatRefElem);
// [SC] add 'TwoA/RankOrder/Ranks/Rank/PCategory@xsd:idref' attribute
XAttribute idrefAttr = new XAttribute(XMLFactory.IDREF_ATTR, "" + pcat.Id);
pcatRefElem.Add(idrefAttr);
}
}
}
else
{
Log(Severity.Warning, "Rank order is missing while transforming KStructure object into XML format.");
}
// [SC] creates elements for 'KStructure'
if (kStructure.hasRanks())
{
kStructure.sortAscending();
// [SC] add 'TwoA/KStructure' element
XElement kStructureElem = new XElement(XMLFactory.KSTRUCTURE_ELEM);
twoAElem.Add(kStructureElem);
// [SC] iterate through KSRanks and create corresponding XML elements
for (int rankCounter = 0; rankCounter < kStructure.getRankCount(); rankCounter++)
{
KSRank rank = kStructure.getRankAt(rankCounter);
// [SC] add 'TwoA/KStructure/KSRank' element
XElement ksRankElem = new XElement(XMLFactory.KSRANK_ELEM);
kStructureElem.Add(ksRankElem);
// [SC] add 'TwoA/KStructure/KSRank@Index' attribute
XAttribute indexAttr = new XAttribute(XMLFactory.INDEX_ATTR, "" + rank.RankIndex);
ksRankElem.Add(indexAttr);
// [SC] iterate through states and add corresponding XML elements
for (int stateCounter = 0; stateCounter < rank.getStateCount(); stateCounter++)
{
KState state = rank.getStateAt(stateCounter);
// [SC] add 'TwoA/KStructure/KSRank/KState' element with 'xsd:id' attribute
XElement stateElem = new XElement(XMLFactory.KSTATE_ELEM);
ksRankElem.Add(stateElem);
// [SC] add 'TwoA/KStructure/KSRank/KState@xsd:id' attribute
XAttribute idAttr = new XAttribute(XMLFactory.ID_ATTR, "" + state.Id);
stateElem.Add(idAttr);
// [SC] add 'TwoA/KStructure/KSRank/KState@Type' attribute
XAttribute typeAttr = new XAttribute(XMLFactory.TYPE_ATTR, "" + state.StateType);
stateElem.Add(typeAttr);
// [SC] add 'TwoA/KStructure/KSRank/KState/PCategories' list element
XElement pcatsElem = new XElement(XMLFactory.PCATS_ELEM);
stateElem.Add(pcatsElem);
// [SC] iterate through categories in the state
for (int catCounter = 0; catCounter < state.getCategoryCount(); catCounter++)
{
PCategory pcat = state.getCategoryAt(catCounter);
// [SC] add 'TwoA/KStructure/KSRank/KState/PCategories/PCategory' element with 'xsd:idref' attribute
XElement pcatElem = new XElement(XMLFactory.PCAT_ELEM);
pcatsElem.Add(pcatElem);
// [SC] add 'TwoA/KStructure/KSRank/KState/PCategories/PCategory@xsd:idref' attribute
XAttribute idrefAttr = new XAttribute(XMLFactory.IDREF_ATTR, "" + pcat.Id);
pcatElem.Add(idrefAttr);
}
// [SC] add 'TwoA/KStructure/KSRank/KState/PreviousStates' list element
XElement prevStatesElem = new XElement(XMLFactory.PREV_STATES_ELEM);
stateElem.Add(prevStatesElem);
// [SC] iterate through immediate prerequisite states in the gradient
for (int prevStateCounter = 0; prevStateCounter < state.getPrevStateCount(); prevStateCounter++)
{
KState prevState = state.getPrevStateAt(prevStateCounter);
// [SC] add 'TwoA/KStructure/KSRank/KState/PreviousStates/KState' element with 'xsd:idref' attribute
XElement prevStateElem = new XElement(XMLFactory.KSTATE_ELEM);
prevStatesElem.Add(prevStateElem);
// [SC] add 'TwoA/KStructure/KSRank/KState/PreviousStates/KState@xsd:idref' attribute
XAttribute idrefAttr = new XAttribute(XMLFactory.IDREF_ATTR, "" + prevState.Id);
prevStateElem.Add(idrefAttr);
}
// [SC] add 'TwoA/KStructure/KSRank/KState/NextStates' list element
XElement nextStatesElem = new XElement(XMLFactory.NEXT_STATES_ELEM);
stateElem.Add(nextStatesElem);
// [SC] iterate through immediate next states in the gradient
for (int nextStateCounter = 0; nextStateCounter < state.getNextStateCount(); nextStateCounter++)
{
KState nextState = state.getNextStateAt(nextStateCounter);
// [SC] add 'TwoA/KStructure/KSRank/KState/NextStates/KState' element with 'xsd:idref' attribute
XElement nextStateElem = new XElement(XMLFactory.KSTATE_ELEM);
nextStatesElem.Add(nextStateElem);
// [SC] add 'TwoA/KStructure/KSRank/KState/NextStates/KState@xsd:idref' attribute
XAttribute idrefAttr = new XAttribute(XMLFactory.IDREF_ATTR, "" + nextState.Id);
nextStateElem.Add(idrefAttr);
}
}
}
}
else
{
Log(Severity.Warning, "Knowledge structure is missing while transforming KStructure object into XML format.");
}
return(doc);
}