/// <inheritdoc />
public override T Dequeue()
{
if (_events.Count > _threshold)
{
return(_events.Dequeue());
}
throw new InvalidOperationException("Event queue is empty");
}
public async Task StartListening()
{
while (true)
{
var dispatchedEvent = _eventQueue.Dequeue();
var strategy = _dispatcherStrategyFactory.GetStrategy(dispatchedEvent.DispatcherStrategy);
await strategy.DispatchEventAsync(dispatchedEvent.EndpointUrl, dispatchedEvent.Payload);
}
}
public void Publish(string pluginName, IEventPublisher callback)
{
while (ququedEventsQueue.GetCount(pluginName) > 0)
{
var e = ququedEventsQueue.Peek(pluginName);
if (RePublish(pluginName, e, callback))
{
ququedEventsQueue.Dequeue(pluginName);
}
else
{
logger.Warn("Can not send event {0} for plugin {1} so this loop was break.", e, pluginName);
break;
}
}
}
public static IEventBase?Dequeue(this IEventQueue eventQueue)
{
return(eventQueue.Dequeue(DefaultQueueName));
}
public static bool TryDequeue(this IEventQueue eventQueue, string queueName, out IEventBase? @event)
{
@event = eventQueue.Dequeue(queueName);
return(@event is not null);
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'parseTypeCollectionPropertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Collection Parse Type Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionParseTypeCollectionPropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Parse Type Collection Property Element");
}
//Get the first Event, should be an ElementEvent
//Type checking is done by the Parent Production
IRdfXmlEvent first = eventlist.Dequeue();
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
//Apply Namespaces
this.ApplyNamespaces(context, element);
//Validate Attributes
String ID = String.Empty;
if (element.Attributes.Count > 2)
{
//Can't be more than 2 Attributes, only allowed an optional rdf:ID and a required rdf:parseType
throw ParserHelper.Error("An Property Element with Parse Type 'Collection' was encountered with too many Attributes. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Collection'", "Parse Type Collection Property Element", element);
}
else
{
//Check the attributes that do exist
foreach (AttributeEvent a in element.Attributes)
{
if (RdfXmlSpecsHelper.IsIDAttribute(a))
{
ID = "#" + a.Value;
}
else if (a.QName.Equals("rdf:parseType"))
{
//OK
}
else
{
//Invalid Attribute
throw ParserHelper.Error("Unexpected Attribute '" + a.QName + "' was encountered on a Property Element with Parse Type 'Collection'. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Collection'", "Parse Type Collection Property Element", element);
}
}
}
//Build sequence of Blank Nodes
IRdfXmlEvent next;
IRdfXmlEvent nodeElement;
Queue<ElementEvent> seqNodes = new Queue<ElementEvent>();
while (eventlist.Count > 1)
{
#region Node Element Processing
//Need to process the Node Element first
//Create a new Sublist
IEventQueue<IRdfXmlEvent> subevents = new EventQueue<IRdfXmlEvent>();
int nesting = 0;
nodeElement = eventlist.Peek();
//Add Node Element to sequence
seqNodes.Enqueue((ElementEvent)nodeElement);
//Gather the Sublist taking account of nesting
do
{
next = eventlist.Dequeue();
subevents.Enqueue(next);
if (next is ElementEvent)
{
nesting++;
}
else if (next is EndElementEvent)
{
nesting--;
}
} while (nesting > 0);
//Call the next Grammar Production
this.GrammarProductionNodeElement(context, subevents);
#endregion
}
//Build a triple expressing the start of the list (which may be an empty list)
INode subj, pred, obj;
INode firstPred, restPred;
INode b1, b2;
//Subject comes from Parent
ElementEvent parentElement = (ElementEvent)parent;
subj = parentElement.SubjectNode;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID.Substring(1), subj);
}
//Predicate from the Element
pred = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
if (seqNodes.Count > 0)
{
//Non-empty list
ElementEvent node;
//Get first Element from the Queue
node = seqNodes.Dequeue();
//Object is first thing in the Sequence which we create a Blank Node for
b1 = context.Handler.CreateBlankNode();
//Assert
if (!context.Handler.HandleTriple(new Triple(subj, pred, b1))) ParserHelper.Stop();
//Reify if applicable
if (!ID.Equals(String.Empty))
{
//Resolve the Uri
UriReferenceEvent uriref = new UriReferenceEvent(ID, String.Empty);
IUriNode uri = this.Resolve(context, uriref, element.BaseUri);
this.Reify(context, uri, subj, pred, b1);
}
//Set the first element in the list
subj = b1;
firstPred = context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfListFirst));
if (!context.Handler.HandleTriple(new Triple(subj, firstPred, node.SubjectNode))) ParserHelper.Stop();
//Middle elements of the list
restPred = context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfListRest));
while (seqNodes.Count >= 1)
{
node = seqNodes.Dequeue();
//Set Node 2 to be the rest of the previous items list
b2 = context.Handler.CreateBlankNode();
if (!context.Handler.HandleTriple(new Triple(b1, restPred, b2))) ParserHelper.Stop();
//Set Node 2 to be the start of it's own list
if (!context.Handler.HandleTriple(new Triple(b2, firstPred, node.SubjectNode))) ParserHelper.Stop();
b1 = b2;
}
//Set last element of the list to have its rest as nil
if (!context.Handler.HandleTriple(new Triple(b1, restPred, context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfListNil))))) ParserHelper.Stop();
}
else
{
//Empty list
//Object is therefore rdf:nil
obj = context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfListNil));
//Assert
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
//Reify if applicable
if (!ID.Equals(String.Empty))
{
//Resolve the Uri
UriReferenceEvent uriref = new UriReferenceEvent(ID, String.Empty);
IUriNode uri = this.Resolve(context, uriref, element.BaseUri);
this.Reify(context, uri, subj, pred, obj);
}
}
//Check last event is an EndElementEvent
next = eventlist.Dequeue();
if (!(next is EndElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + next.GetType().ToString() + "', expected an EndElementEvent to terminate a Parse Type Collection Property Element!", "Parse Type Collection Property Element", next);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'nodeElementList'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events to apply the Production to</param>
private void GrammarProductionNodeElementList(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTrace("Node Element List");
}
IRdfXmlEvent next;
//Want to break up into a number of sublists
while (eventlist.Count > 0)
{
//Create a new Sublist
IEventQueue<IRdfXmlEvent> subevents = new EventQueue<IRdfXmlEvent>();
int nesting = 0;
//Gather the Sublist taking account of nesting
do
{
next = eventlist.Dequeue();
subevents.Enqueue(next);
if (next is ElementEvent)
{
nesting++;
}
else if (next is EndElementEvent)
{
nesting--;
}
} while (nesting > 0);
//Call the next Grammar Production
this.GrammarProductionNodeElement(context, subevents);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'nodeElement'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Node Element and its Children to apply the Production to</param>
private void GrammarProductionNodeElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Node Element");
}
//Get First Event in the Queue
IRdfXmlEvent first = eventlist.Dequeue();
//Check it's an ElementEvent
if (!(first is ElementEvent))
{
//Unexpected Event
throw ParserHelper.Error("Expected an ElementEvent but encountered a '" + first.GetType().ToString() + "'", "Node Element", first);
}
//Check it has a valid Uri
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
this.ApplyNamespaces(context, element);
if (!RdfXmlSpecsHelper.IsNodeElementUri(element.QName))
{
throw ParserHelper.Error("A Node Element was encountered with an invalid URI '" + element.QName + "' \nCore Syntax Terms, Old Syntax Terms and rdf:li cannot be used as Node Element URIs", "Node Element", element);
}
//Check the set of Attributes is Valid
int limitedAttributesFound = 0;
String ID = String.Empty;
foreach (AttributeEvent attr in element.Attributes)
{
if (RdfXmlSpecsHelper.IsIDAttribute(attr))
{
ID = attr.Value;
limitedAttributesFound++;
//Set the Subject
element.Subject = new UriReferenceEvent("#" + attr.Value, attr.SourceXml);
}
else if (RdfXmlSpecsHelper.IsNodeIDAttribute(attr))
{
limitedAttributesFound++;
//Validate the Node ID
if (!XmlSpecsHelper.IsName(attr.Value))
{
throw ParserHelper.Error("The value '" + attr.Value + "' for rdf:nodeID is not valid, RDF Node IDs can only be valid Names as defined by the W3C XML Specification", "Node Element", attr);
}
//Set the Subject
element.Subject = new BlankNodeIDEvent(attr.Value, attr.SourceXml);
}
else if (RdfXmlSpecsHelper.IsAboutAttribute(attr))
{
limitedAttributesFound++;
//Set the Subject
element.Subject = new UriReferenceEvent(attr.Value, attr.SourceXml);
}
else if (RdfXmlSpecsHelper.IsPropertyAttribute(attr))
{
//Don't need to do anything here yet
}
else
{
//Unknown and Unexpected Attribute Type
throw ParserHelper.Error("Unexpected Attribute '" + attr.QName + "' was encountered!", "Node Element", element);
}
//Can't have more than 1 of ID, Node ID or About Attributes
if (limitedAttributesFound > 1)
{
throw ParserHelper.Error("A Node Element can only have 1 of the following attributes: rdf:id, rdf:nodeID, rdf:about", "Node Element", element);
}
}
//Generate a Blank Node ID if our Subject is empty
if (element.Subject == null)
{
element.Subject = new BlankNodeIDEvent(element.SourceXml);
}
//Add statements as necessary
INode subj, pred, obj;
if (element.SubjectNode == null)
{
//Don't always want to drop in here since the SubjectNode may already be set elsewhere
if (element.Subject is UriReferenceEvent)
{
UriReferenceEvent uri = (UriReferenceEvent)element.Subject;
subj = this.Resolve(context, uri, element.BaseUri);
}
else if (element.Subject is BlankNodeIDEvent)
{
BlankNodeIDEvent blank = (BlankNodeIDEvent)element.Subject;
//Select whether we need to generate an ID or if there's one given for the Blank Node
//Note that we let the Graph class handle generation of IDs
if (blank.Identifier.Equals(String.Empty))
{
subj = context.Handler.CreateBlankNode();
}
else
{
subj = context.Handler.CreateBlankNode(blank.Identifier);
}
}
else
{
throw ParserHelper.Error("Unexpected Subject generated for a Triple", "Node Element", element.Subject);
}
} else {
subj = element.SubjectNode;
}
//Set the Subject Node property of the Event for later reuse
element.SubjectNode = subj;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID, subj);
}
if (!element.QName.Equals("rdf:Description") && !element.QName.Equals(":Description"))
{
//Assert a Triple regarding Type
pred = context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfType));
obj = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
}
//Go back over Attributes looking for property attributes
foreach (AttributeEvent attr in element.Attributes)
{
if (RdfXmlSpecsHelper.IsPropertyAttribute(attr))
{
if (attr.QName.Equals("rdf:type"))
{
//Generate a Type Triple
pred = context.Handler.CreateUriNode(UriFactory.Create(RdfSpecsHelper.RdfType));
//Resolve URIRef into a Uri Node
UriReferenceEvent uriref = new UriReferenceEvent(attr.Value, attr.SourceXml);
obj = this.Resolve(context, uriref, element.BaseUri);
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
}
else
{
//Generate a Property Triple
pred = context.Handler.CreateUriNode(UriFactory.Create(Tools.ResolveQName(attr.QName, context.Namespaces, context.BaseUri)));
//Add Language to Literal if necessary
if (element.Language.Equals(String.Empty))
{
obj = context.Handler.CreateLiteralNode(attr.Value);
}
else
{
obj = context.Handler.CreateLiteralNode(attr.Value, element.Language);
}
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
}
}
}
//Handle Child Elements
IEventQueue<IRdfXmlEvent> children = new EventQueue<IRdfXmlEvent>();
while (eventlist.Count > 1)
{
children.Enqueue(eventlist.Dequeue());
}
if (children.Count > 0) this.GrammarProductionPropertyElementList(context, children, element);
//Check Last Event in queue is an EndElement event
IRdfXmlEvent last = eventlist.Dequeue();
if (!(last is EndElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + last.GetType().ToString() + "', expected an EndElement Event", "NodeElement", last);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'literalPropertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Literal Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionLiteralPropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Literal Property Element");
}
//Get the 3 Events (should only be three)
IRdfXmlEvent first, middle, last;
first = eventlist.Dequeue();
middle = eventlist.Dequeue();
last = eventlist.Dequeue();
//If Queue is non-empty then Error
if (eventlist.Count > 0)
{
throw ParserHelper.Error("Too many events encountered while trying to parse a Literal Property Element", first);
}
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
//Apply Namespaces
this.ApplyNamespaces(context, element);
//Validate that the middle event is a TextEvent
if (!(middle is TextEvent))
{
throw ParserHelper.Error("Unexpected event '" + middle.GetType().ToString() + "', expected a TextEvent in a Literal Property Element", middle);
}
TextEvent text = (TextEvent)middle;
//Validate the Attributes
String ID = String.Empty;
String datatype = String.Empty;
if (element.Attributes.Count > 2)
{
throw ParserHelper.Error("A Literal Property Element contains too many attributes, only rdf:ID and rdf:datatype are permitted", element);
}
else
{
//Only rdf:ID and rdf:datatype allowed
foreach (AttributeEvent a in element.Attributes)
{
if (RdfXmlSpecsHelper.IsIDAttribute(a)) {
ID = "#" + a.Value;
}
else if (RdfXmlSpecsHelper.IsDataTypeAttribute(a))
{
datatype = a.Value;
}
else
{
throw ParserHelper.Error("A Literal Property Element contains an unexpected attribute, only rdf:ID and rdf:datatype are permitted", element);
}
}
}
//Create the Nodes for the Graph
INode subj, pred, obj;
//Get the Subject from the Parent
ElementEvent parentEl = (ElementEvent)parent;
subj = parentEl.SubjectNode;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID.Substring(1), subj);
}
//Create a Predicate from this Element
pred = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
//Create an Object from the Text Event
if (datatype.Equals(String.Empty))
{
//No Type with possible Language
if (element.Language.Equals(String.Empty))
{
obj = context.Handler.CreateLiteralNode(text.Value);
}
else
{
obj = context.Handler.CreateLiteralNode(text.Value, element.Language);
}
}
else
{
//Typed
//Resolve the Datatype Uri
UriReferenceEvent dtref = new UriReferenceEvent(datatype, String.Empty);
IUriNode dturi = this.Resolve(context, dtref, element.BaseUri);
obj = context.Handler.CreateLiteralNode(text.Value, dturi.Uri);
}
//Assert the Triple
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
//Reify if applicable
if (!ID.Equals(String.Empty))
{
//Resolve the Uri
UriReferenceEvent uriref = new UriReferenceEvent(ID, String.Empty);
IUriNode uri = this.Resolve(context, uriref,element.BaseUri);
this.Reify(context, uri, subj, pred, obj);
}
}
/// <summary>
/// Helper function which inserts an Element back on the front of a Queue
/// </summary>
/// <param name="eventlist">Queue to insert onto the Front of</param>
/// <param name="evt">Event to put on the front of the Queue</param>
private void QueueJump(IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent evt)
{
Stack<IRdfXmlEvent> temp = new Stack<IRdfXmlEvent>();
temp.Push(evt);
while (eventlist.Count > 0)
{
temp.Push(eventlist.Dequeue());
}
foreach (IRdfXmlEvent e in temp.Reverse())
{
eventlist.Enqueue(e);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'resourcePropertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Resource Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionResourcePropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Resource Property Element");
}
//Cast to an ElementEvent
//We don't validate type here since we know this will be an ElementEvent because the calling function
//will have done this validation previously
IRdfXmlEvent first = eventlist.Dequeue();
IRdfXmlEvent next = eventlist.Peek();
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
//Apply Namespaces
this.ApplyNamespaces(context, element);
//Only allowed one attribute max which must be an ID attribute
String ID = String.Empty;
if (element.Attributes.Count > 1)
{
throw ParserHelper.Error("A Resource Property Element contains too many Attributes, only rdf:ID is permitted", element);
}
else if (element.Attributes.Count == 1)
{
if (!RdfXmlSpecsHelper.IsIDAttribute(element.Attributes.First()))
{
throw ParserHelper.Error("A Resource Property Element was encountered with a single attribute which was not rdf:ID, only rdf:ID is permitted", element);
}
else
{
ID = element.Attributes.First().Value;
}
}
//Next must be an ElementEvent
if (!(next is ElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + next.GetType().ToString() + "', expected an ElementEvent as the first Event in a Resource Property Elements Event list", next);
}
//Get list of Sub Events
IEventQueue<IRdfXmlEvent> subevents = new EventQueue<IRdfXmlEvent>();
while (eventlist.Count > 1)
{
subevents.Enqueue(eventlist.Dequeue());
}
this.GrammarProductionNodeElement(context, subevents);
//Check Last is an EndElementEvent
IRdfXmlEvent last = eventlist.Dequeue();
if (!(last is EndElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + last.GetType().ToString() + "', expected an EndElement Event", last);
}
//Now we can generate the relevant RDF
INode subj, pred, obj;
//Validate the Type of the Parent
if (!(parent is ElementEvent))
{
throw ParserHelper.Error("Unexpected Parent Event '" + parent.GetType().ToString() + "', expected an ElementEvent", parent);
}
ElementEvent parentEl = (ElementEvent)parent;
//Get the Subject Node from the Parent
subj = parentEl.SubjectNode;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID, subj);
}
//Create a Predicate from this Element
pred = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
//Get the Object Node from the Child Node
ElementEvent child = (ElementEvent)next;
obj = child.SubjectNode;
//Assert the Triple
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
//Add Reification where appropriate
if (element.Attributes.Count == 1)
{
//Must be an rdf:ID attribute as we've validated this earlier
//Get the Attribute Event and generate a Uri from it
AttributeEvent attr = element.Attributes.First();
UriReferenceEvent uriref = new UriReferenceEvent("#" + attr.Value, attr.SourceXml);
IUriNode uri = this.Resolve(context, uriref, element.BaseUri);
this.Reify(context, uri, subj, pred, obj);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'propertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionPropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Property Element");
}
//Get first thing from the Queue
IRdfXmlEvent first = eventlist.Dequeue();
ElementEvent element;
//Must be an ElementEvent
if (!(first is ElementEvent))
{
//Unexpected Event
throw ParserHelper.Error("Expected an ElementEvent but encountered a '" + first.GetType().ToString() + "'", "PropertyElement", first);
}
//Validate the Uri
element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
this.ApplyNamespaces(context, element);
if (!RdfXmlSpecsHelper.IsPropertyElementURI(element.QName))
{
//Invalid Uri
throw ParserHelper.Error("A Property Element was encountered with an invalid URI '" + element.QName + "'\nCore Syntax Terms, Old Syntax Terms and rdf:Description cannot be used as Property Element URIs", "PropertyElement", element);
}
//List Expansion
if (element.QName.Equals("rdf:li"))
{
UriReferenceEvent u = this.ListExpand(parent);
element.SetUri(u);
}
//Need to select what to do based on the Type of Property Element
IRdfXmlEvent next = eventlist.Peek();
//This call inserts the first element back at the head of the queue
//Most of the sub-productions here need this
//Would ideally use Stacks instead of Queues but Queues make more sense for most of the Parsing
this.QueueJump(eventlist, first);
if (element.ParseType == RdfXmlParseType.None)
{
//A Resource/Literal Property Element
if (next is ElementEvent)
{
//Resource
this.GrammarProductionResourcePropertyElement(context, eventlist, parent);
}
else if (next is TextEvent)
{
//Literal
this.GrammarProductionLiteralPropertyElement(context, eventlist, parent);
}
else if (next is EndElementEvent)
{
//An Empty Property Element
this.GrammarProductionEmptyPropertyElement(context, element, parent);
}
else
{
//Error
throw ParserHelper.Error("An Element which should be Parsed with the Default Parsing Rules was encountered without a valid subsequent Event - Parser cannot proceed!", "Property Element", element);
}
}
else if (element.ParseType == RdfXmlParseType.Literal)
{
//A rdf:parseType="Literal" Property Element
this.GrammarProductionParseTypeLiteralPropertyElement(context, eventlist, parent);
}
else if (element.ParseType == RdfXmlParseType.Collection)
{
//A rdf:parseType="Collection" Property Element
this.GrammarProductionParseTypeCollectionPropertyElement(context, eventlist, parent);
}
else if (element.ParseType == RdfXmlParseType.Resource)
{
//A rdf:parseType="Resource" Property Element
this.GrammarProductionParseTypeResourcePropertyElement(context, eventlist, parent);
}
else if (next is EndElementEvent)
{
//An Empty Property Element
this.GrammarProductionEmptyPropertyElement(context, element, parent);
}
else
{
//Error
throw ParserHelper.Error("An Element without a known Parse Type was encountered Or the Parser was unable to determine what to do based on the subsequent event - Parser cannot proceed!", "Node Element", element);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'parseTypeResourcePropertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Resource Parse Type Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionParseTypeResourcePropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Parse Type Resource Property Element");
}
//Get the first Event, should be an ElementEvent
//Type checking is done by the Parent Production
IRdfXmlEvent first = eventlist.Dequeue();
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
//Apply Namespaces
this.ApplyNamespaces(context, element);
//Validate Attributes
String ID = String.Empty;
if (element.Attributes.Count > 2)
{
//Can't be more than 2 Attributes, only allowed an optional rdf:ID and a required rdf:parseType
throw ParserHelper.Error("An Property Element with Parse Type 'Resource' was encountered with too many Attributes. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Resource'", "Parse Type Resource Property Element", element);
}
else
{
//Check the attributes that do exist
foreach (AttributeEvent a in element.Attributes)
{
if (RdfXmlSpecsHelper.IsIDAttribute(a))
{
ID = "#" + a.Value;
}
else if (a.QName.Equals("rdf:parseType"))
{
//OK
}
else
{
//Invalid Attribute
throw ParserHelper.Error("Unexpected Attribute '" + a.QName + "' was encountered on a Property Element with Parse Type 'Resource'. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Resource'", "Parse Type Resource Property Element", element);
}
}
}
//Add a Triple about this
INode subj, pred, obj;
//Get the Subject from the Parent
ElementEvent parentEvent = (ElementEvent)parent;
subj = parentEvent.SubjectNode;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID.Substring(1), subj);
}
//Create the Predicate from the Element
pred = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
//Generate a Blank Node ID for the Object
obj = context.Handler.CreateBlankNode();
//Assert
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
//Reify if applicable
if (!ID.Equals(String.Empty))
{
//Resolve the Uri
UriReferenceEvent uriref = new UriReferenceEvent(ID, String.Empty);
IUriNode uri = this.Resolve(context, uriref,element.BaseUri);
this.Reify(context, uri, subj, pred, obj);
}
//Get the next event in the Queue which should be either an Element Event or a End Element Event
//Validate this
IRdfXmlEvent next = eventlist.Dequeue();
if (next is EndElementEvent)
{
//Content is Empty so nothing else to do
}
else if (next is ElementEvent)
{
//Non-Empty Content so need to build a sequence of new events
IEventQueue<IRdfXmlEvent> subEvents = new EventQueue<IRdfXmlEvent>();
//Create an rdf:Description event as the container
ElementEvent descrip = new ElementEvent("rdf:Description", element.BaseUri, String.Empty);
descrip.Subject = new BlankNodeIDEvent(String.Empty);
descrip.SubjectNode = obj;
subEvents.Enqueue(descrip);
//Add the current element we were looking at
subEvents.Enqueue(next);
//Add rest of events in list (exceot the last)
while (eventlist.Count > 1)
{
subEvents.Enqueue(eventlist.Dequeue());
}
//Terminate with an EndElement Event
subEvents.Enqueue(new EndElementEvent());
//Process with Node Element Production
this.GrammarProductionNodeElement(context, subEvents);
//Get the last thing in the List
next = eventlist.Dequeue();
}
else
{
throw ParserHelper.Error("Unexpected Event '" + next.GetType().ToString() + "', expected an ElementEvent or EndElementEvent after a Parse Type Resource Property Element!", "Parse Type Resource Property Element", next);
}
//Check for the last thing being an EndElement Event
if (!(next is EndElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + next.GetType().ToString() + "', expected an EndElementEvent to terminate a Parse Type Resource Property Element!", "Parse Type Resource Property Element", next);
}
}
/// <summary>
/// Implementation of the RDF/XML Grammar Production 'parseTypeLiteralPropertyElt'
/// </summary>
/// <param name="context">Parser Context</param>
/// <param name="eventlist">Queue of Events that make up the Literal Parse Type Property Element and its Children</param>
/// <param name="parent">Parent Event (ie. Node) of the Property Element</param>
private void GrammarProductionParseTypeLiteralPropertyElement(RdfXmlParserContext context, IEventQueue<IRdfXmlEvent> eventlist, IRdfXmlEvent parent)
{
//Tracing
if (this._traceparsing)
{
this.ProductionTracePartial("Parse Type Literal Property Element");
}
//Get the first Event, should be an ElementEvent
//Type checking is done by the Parent Production
IRdfXmlEvent first = eventlist.Dequeue();
ElementEvent element = (ElementEvent)first;
if (this._traceparsing) this.ProductionTracePartial(element);
//Apply Namespaces
this.ApplyNamespaces(context, element);
//Validate Attributes
String ID = String.Empty;
if (element.Attributes.Count > 2)
{
//Can't be more than 2 Attributes, only allowed an optional rdf:ID and a required rdf:parseType
throw ParserHelper.Error("An Property Element with Parse Type 'Literal' was encountered with too many Attributes. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Literal'", "Parse Type Literal Property Element", element);
}
else
{
//Check the attributes that do exist
foreach (AttributeEvent a in element.Attributes)
{
if (RdfXmlSpecsHelper.IsIDAttribute(a))
{
ID = "#" + a.Value;
}
else if (a.QName.Equals("rdf:parseType"))
{
//OK
}
else
{
//Invalid Attribute
throw ParserHelper.Error("Unexpected Attribute '" + a.QName + "' was encountered on a Property Element with Parse Type 'Literal'. Only rdf:ID and rdf:parseType are allowed on Property Elements with Parse Type 'Literal'", "Parse Type Literal Property Element", element);
}
}
}
//Get the next event in the Queue which should be a TypedLiteralEvent
//Validate this
IRdfXmlEvent lit = eventlist.Dequeue();
if (!(lit is TypedLiteralEvent))
{
throw ParserHelper.Error("Unexpected Event '" + lit.GetType().ToString() + "', expected a TypedLiteralEvent after a Property Element with Parse Type 'Literal'", "Parse Type Literal Property Element", lit);
}
//Get the Subject from the Parent
INode subj, pred, obj;
ElementEvent parentEl = (ElementEvent) parent;
subj = parentEl.SubjectNode;
//Validate the ID (if any)
if (!ID.Equals(String.Empty))
{
this.ValidateID(context, ID.Substring(1), subj);
}
//Create the Predicate from the Element
pred = this.Resolve(context, element);//context.Handler.CreateUriNode(element.QName);
//Create the Object from the Typed Literal
TypedLiteralEvent tlit = (TypedLiteralEvent)lit;
//At the moment we're just going to ensure that we normalize it to Unicode Normal Form C
String xmllit = tlit.Value;
#if !NO_NORM
xmllit = xmllit.Normalize();
#endif
obj = context.Handler.CreateLiteralNode(xmllit, UriFactory.Create(tlit.DataType));
//Assert the Triple
if (!context.Handler.HandleTriple(new Triple(subj, pred, obj))) ParserHelper.Stop();
//Reify if applicable
if (!ID.Equals(String.Empty))
{
//Resolve the Uri
UriReferenceEvent uriref = new UriReferenceEvent(ID, String.Empty);
IUriNode uri = this.Resolve(context, uriref,element.BaseUri);
this.Reify(context, uri, subj, pred, obj);
}
//Check for the last thing being an EndElement Event
IRdfXmlEvent next = eventlist.Dequeue();
if (!(next is EndElementEvent))
{
throw ParserHelper.Error("Unexpected Event '" + next.GetType().ToString() + "', expected an EndElementEvent to terminate a Parse Type Literal Property Element!", "Parse Type Literal Property Element", next);
}
}
public IReadOnlyCollection <IDomainEvent> DequeueAllEvents() => _eventQueue.Dequeue();
public static bool TryDequeue(this IEventQueue eventQueue, out IEventBase @event)
{
@event = eventQueue.Dequeue(DefaultQueueName);
return(null != @event);
}