private String ParseTextContent(RdfACoreParserContext context)
{
int i = 1;
IRdfAEvent next;
StringBuilder output = new StringBuilder();
List <IRdfAEvent> events = new List <IRdfAEvent>();
do
{
next = context.Events.Dequeue();
switch (next.EventType)
{
case Event.Element:
i++;
break;
case Event.EndElement:
i--;
break;
case Event.Text:
output.Append(((TextEvent)next).Text);
break;
}
events.Add(next);
} while (i > 0);
foreach (IRdfAEvent evt in events)
{
context.Requeue(evt);
}
return(output.ToString());
}
public override void ParseLiteralLanguage(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("xml:lang"))
{
if (RdfSpecsHelper.IsValidLangSpecifier(evt["xml:lang"]))
{
context.Language = evt["xml:lang"];
}
}
}
public override void ParseLiteralLanguage(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("xml:lang"))
{
if (RdfSpecsHelper.IsValidLangSpecifier(evt["xml:lang"]))
{
context.Language = evt["xml:lang"];
}
}
}
private Uri ResolveUri(RdfACoreParserContext context, String value)
{
try
{
String uri = Tools.ResolveUri(value, context.BaseUri.ToSafeString());
return(new Uri(uri));
}
catch
{
return(null);
}
}
private String ParseXmlContent(RdfACoreParserContext context)
{
int i = 1;
IRdfAEvent next;
Stack <String> openElements = new Stack <string>();
StringBuilder output = new StringBuilder();
do
{
next = context.Events.Peek();
switch (next.EventType)
{
case Event.Element:
i++;
output.Append("<" + ((ElementEvent)next).Name);
openElements.Push(((ElementEvent)next).Name);
foreach (KeyValuePair <String, String> attr in next.Attributes)
{
output.Append(" " + attr.Key + "=\"" + attr.Value + "\"");
}
context.Events.Dequeue();
if (context.Events.Peek().EventType == Event.EndElement)
{
context.Events.Dequeue();
i--;
output.Append(" />");
openElements.Pop();
}
else
{
output.Append(">");
}
continue;
case Event.EndElement:
i--;
if (i == 0)
{
break;
}
output.Append("</" + openElements.Pop() + ">");
break;
case Event.Text:
output.Append(((TextEvent)next).Text);
break;
}
context.Events.Dequeue();
} while (i > 0);
return(output.ToString());
}
public override void ParseExtensions(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("xml:base"))
{
try
{
context.BaseUri = new Uri(Tools.ResolveUri(evt["xml:base"], context.BaseUri.ToSafeString()));
}
catch
{
//If URI resolution fails then cannot change the Base URI
}
}
}
public override void ParseExtensions(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("xml:base"))
{
try
{
context.BaseUri = new Uri(Tools.ResolveUri(evt["xml:base"], context.BaseUri.ToSafeString()));
}
catch
{
// If URI resolution fails then cannot change the Base URI
}
}
}
public override void ParsePrefixMappings(RdfACoreParserContext context, IRdfAEvent evt)
{
foreach (KeyValuePair <String, String> attr in evt.Attributes)
{
if (attr.Key.Equals("xmlns"))
{
context.Namespaces.AddNamespace(String.Empty, new Uri(Tools.ResolveUri(attr.Value, context.BaseUri.ToSafeString())));
}
else if (attr.Key.StartsWith("xmlns:"))
{
String prefix = attr.Key.Substring(attr.Key.IndexOf(':') + 1);
context.Namespaces.AddNamespace(prefix, new Uri(Tools.ResolveUri(attr.Value, context.BaseUri.ToSafeString())));
}
}
}
private Uri ResolveTerm(RdfACoreParserContext context, String value)
{
if (context.Terms.HasNamespace(value))
{
return(context.Terms.GetNamespaceUri(value));
}
else if (context.DefaultVocabularyUri != null)
{
return(new Uri(context.DefaultVocabularyUri.ToString() + value));
}
else
{
return(null);
}
}
public override void ParsePrefixMappings(RdfACoreParserContext context, IRdfAEvent evt)
{
foreach (KeyValuePair<String, String> attr in evt.Attributes)
{
if (attr.Key.Equals("xmlns"))
{
context.Namespaces.AddNamespace(String.Empty, new Uri(Tools.ResolveUri(attr.Value, context.BaseUri.ToSafeString())));
}
else if (attr.Key.StartsWith("xmlns:"))
{
String prefix = attr.Key.Substring(attr.Key.IndexOf(':') + 1);
context.Namespaces.AddNamespace(prefix, new Uri(Tools.ResolveUri(attr.Value, context.BaseUri.ToSafeString())));
}
}
}
private void ParsePrefixAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
String[] values = evt["prefix"].Split(this._whitespace);
for (int i = 0; i < values.Length - 1; i += 2)
{
String prefix = values[i];
Uri uri = this.ResolveAbsoluteUri(values[i + 1]);
if (uri == null)
{
continue;
}
context.Namespaces.AddNamespace(prefix, uri);
}
}
private INode ParseObjectResource(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("resource"))
{
return(this.ParseResourceAttibute(context, evt));
}
else if (evt.HasAttribute("href"))
{
return(this.ParseHrefAttribute(context, evt));
}
else
{
return(null);
}
}
public void Load(IRdfHandler handler, TextReader input)
{
if (handler == null)
{
throw new RdfParseException("Cannot parse RDF using a null RDF Handler");
}
if (input == null)
{
throw new RdfParseException("Cannpt parse RDF from a null input");
}
try
{
RdfACoreParserContext context = this.GetParserContext(handler, input);
//Before we start parsing check if a Version has been specified
if (context.HostLanguage.Version != null)
{
switch (context.HostLanguage.Version)
{
case RdfAParser.XHtmlPlusRdfA10Version:
case RdfAParser.HtmlPlusRdfA10Version:
//If using RDFa 1.0 then should use the old parser instead
RdfAParser parser = new RdfAParser();
parser.Load(context.Handler, input);
return;
}
}
//For any other RDFa Version use this parser
this.Parse(context);
}
catch
{
try
{
input.Close();
}
catch
{
//No catch actions just trying to clean up
}
throw;
}
}
private INode UriToNode(RdfACoreParserContext context, Uri u)
{
if (u == null)
{
return(null);
}
else if (u.Scheme.Equals("rdfa"))
{
String id = u.ToString().Substring(11);
if (id.Equals(String.Empty))
{
id = "rdfa-special-bnode";
}
return(context.Handler.CreateBlankNode(id));
}
else
{
return(context.Handler.CreateUriNode(u));
}
}
private Uri ResolveCurie(RdfACoreParserContext context, String value)
{
if (value.Contains(":"))
{
String prefix = value.Substring(0, value.IndexOf(':'));
String reference = (prefix.Length + 1 < value.Length ? value.Substring(value.IndexOf(':') + 1) : String.Empty);
if (prefix.Equals(String.Empty))
{
return(new Uri(context.DefaultPrefixMapping.ToString() + reference));
}
else if (prefix.Equals("_"))
{
if (reference.Equals(String.Empty))
{
//Q: Should this throw an error?
if (context.SpecialBNodeSeen)
{
return(null);
}
context.SpecialBNodeSeen = true;
}
return(new Uri("rdfa:bnode:" + reference));
}
else
{
if (context.Namespaces.HasNamespace(prefix))
{
return(new Uri(context.Namespaces.GetNamespaceUri(prefix).ToString() + reference));
}
else
{
return(null);
}
}
}
else
{
return(null);
}
}
private INode ParseRelOrRevSubject(RdfACoreParserContext context, IRdfAEvent evt, bool isRoot)
{
if (evt.HasAttribute("about"))
{
return(this.ParseAboutAttribute(context, evt));
}
else if (evt.HasAttribute("src"))
{
return(this.ParseSrcAttribute(context, evt));
}
else if (isRoot || context.HostLanguage.IsRootElement(evt))
{
return(this.UriToNode(context, this.ParseUri(context, String.Empty, RdfACurieMode.SafeCurieOrCurieOrUri)));
}
else if (evt.HasAttribute("typeof"))
{
return(context.Handler.CreateBlankNode());
}
else
{
return(context.ParentObject);
}
}
private INode ParseSubject(RdfACoreParserContext context, IRdfAEvent evt, bool isRoot, out bool skip)
{
skip = false;
if (evt.HasAttribute("about"))
{
return(this.ParseAboutAttribute(context, evt));
}
else if (evt.HasAttribute("src"))
{
return(this.ParseSrcAttribute(context, evt));
}
else if (evt.HasAttribute("resource"))
{
return(this.ParseResourceAttibute(context, evt));
}
else if (evt.HasAttribute("href"))
{
return(this.ParseHrefAttribute(context, evt));
}
else if (isRoot || context.HostLanguage.IsRootElement(evt))
{
return(this.UriToNode(context, this.ParseUri(context, String.Empty, RdfACurieMode.SafeCurieOrCurieOrUri)));
}
else if (evt.HasAttribute("typeof"))
{
return(context.Handler.CreateBlankNode());
}
else
{
if (evt.HasAttribute("property"))
{
skip = true;
}
return(context.ParentObject);
}
}
private INode ParseAboutAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return(this.UriToNode(context, this.ParseUri(context, evt["about"], RdfACurieMode.SafeCurieOrCurieOrUri)));
}
public virtual void ParseLiteralLanguage(RdfACoreParserContext context, IRdfAEvent evt)
{
}
public override void InitTermMappings(RdfACoreParserContext context)
{
// TODO: Load the RDFa default terms
}
public virtual void ParsePrefixMappings(RdfACoreParserContext context, IRdfAEvent evt)
{
}
public virtual void InitTermMappings(RdfACoreParserContext context)
{
}
private INode ParseHrefAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return this.UriToNode(context, this.ParseUri(context, evt["href"], RdfACurieMode.Uri));
}
private void Parse(RdfACoreParserContext context)
{
try
{
context.Handler.StartRdf();
//Initialise Term Mappings
context.HostLanguage.InitTermMappings(context);
IRdfAEvent current;
bool first = true;
int nesting = 0;
INode rdfType = context.Handler.CreateUriNode(new Uri(RdfSpecsHelper.RdfType));
List <IncompleteTriple> localIncompletes = new List <IncompleteTriple>();
do
{
localIncompletes.Clear();
//Dequeue the next event and increment/decrement nesting as appropriate
current = context.Events.Dequeue();
switch (current.EventType)
{
case Event.Element:
nesting++;
context.IncrementNesting();
break;
case Event.EndElement:
context.DecrementNesting();
nesting--;
continue;
default:
//Otherwise skip the event and continue
continue;
//throw new RdfParseException("Encountered an unexpected event of type '" + current.GetType().ToString() + "' when an Element/End Element event was expected", current.Position);
}
//Stop when nesting level returns to 0
if (nesting == 0)
{
break;
}
//Step 1 - Initialisation
bool skip = false;
INode newSubj = null, currObjResource = null, currObjLiteral = null;
//Before carrying out further steps allow host specific special actions
context.HostLanguage.ParseExtensions(context, current);
//Step 2 - @profile parsing
if (current.HasAttribute("profile"))
{
if (!this.ParseProfileAttribute(context, current))
{
//If an @profile attribute fails to parse then must ignore the current subtree
int i = 0;
IRdfAEvent next;
do
{
next = context.Events.Dequeue();
//Keep track of nesting in the subtree
if (next.EventType == Event.Element)
{
i++;
}
if (next.EventType == Event.EndElement)
{
i--;
}
} while (i > 0 && next.EventType != Event.EndElement && context.Events.Count > 0);
//If couldn't ignore a valid subtree then error
if (context.Events.Count == 0)
{
throw new RdfParseException("Encountered an @profile attribute which pointed to a malformed profile which meant the relevant subtree of the document should be ignored but the document does not contain a well formed subtree");
}
//If a bad @profile then continue after we've ignored the subtree
continue;
}
}
//Step 3 - @vocab parsing
if (current.HasAttribute("vocab"))
{
this.ParseVocabAttribute(context, current);
}
//Step 4 - @prefix parsing (plus any other mechanisms defined by the host language)
if (current.HasAttribute("prefix"))
{
this.ParsePrefixAttribute(context, current);
}
context.HostLanguage.ParsePrefixMappings(context, current);
//Step 5 - Language parsing
context.HostLanguage.ParseLiteralLanguage(context, current);
if (!current.HasAttribute("rel") && !current.HasAttribute("rev"))
{
//Step 6 - If no @rel or @rev establish a subject
newSubj = this.ParseSubject(context, current, nesting == 1, out skip);
}
else
{
//Step 7 - Use @rel or @rev to establish a subject and an object resource
newSubj = this.ParseRelOrRevSubject(context, current, nesting == 1);
currObjResource = this.ParseObjectResource(context, current);
}
//Step 8 - If there is a non-null subject process @typeof
if (newSubj != null)
{
if (current.HasAttribute("typeof"))
{
foreach (INode n in this.ParseTypeofAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(newSubj, rdfType, n)))
{
ParserHelper.Stop();
}
}
}
}
if (currObjResource != null)
{
//Step 9 - If there is a non-null object resource generate triples
if (current.HasAttribute("rel"))
{
foreach (INode n in this.ParseRelAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(newSubj, n, currObjResource)))
{
ParserHelper.Stop();
}
}
}
if (current.HasAttribute("rev"))
{
foreach (INode n in this.ParseRevAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(currObjResource, n, newSubj)))
{
ParserHelper.Stop();
}
}
}
}
else if (newSubj != null)
{
//Step 10 - If there is no object resource but there are predicates generate incomplete triples
currObjResource = context.Handler.CreateBlankNode();
if (current.HasAttribute("rel"))
{
foreach (INode n in this.ParseRelAttribute(context, current))
{
localIncompletes.Add(new IncompleteTriple(n, IncompleteTripleDirection.Forward));
}
}
if (current.HasAttribute("rev"))
{
foreach (INode n in this.ParseRevAttribute(context, current))
{
localIncompletes.Add(new IncompleteTriple(n, IncompleteTripleDirection.Reverse));
}
}
}
//Step 11 - Establish the current object literal
if (newSubj != null && current.HasAttribute("property"))
{
//Must be an @property attribute in order for any triples to be generated
List <INode> ps = this.ParsePropertyAttribute(context, current).ToList();
if (ps.Count > 0)
{
Uri dtUri;
if (current.HasAttribute("content"))
{
//If @content is present then either a plain/typed literal
if (current.HasAttribute("datatype"))
{
//@datatype is present so typed literal
dtUri = this.ParseUri(context, current["datatype"], RdfACurieMode.TermOrCurieOrAbsUri);
currObjLiteral = context.Handler.CreateLiteralNode(current["content"], dtUri);
}
else
{
//Plain literal
currObjLiteral = context.Handler.CreateLiteralNode(current["content"], context.Language);
}
}
else if (current.HasAttribute("datatype"))
{
//Typed literal
dtUri = this.ParseUri(context, current["datatype"], RdfACurieMode.TermOrCurieOrAbsUri);
if (dtUri != null)
{
if (dtUri.ToString().Equals(RdfSpecsHelper.RdfXmlLiteral))
{
//XML Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseXmlContent(context), dtUri);
}
else
{
//Typed Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), dtUri);
}
}
else
{
//If datatype does not resolve fall back to plain literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), context.Language);
}
}
else
{
//Plain Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), context.Language);
}
//Generate the relevant triples
foreach (INode p in ps)
{
if (!context.Handler.HandleTriple(new Triple(newSubj, p, currObjLiteral)))
{
ParserHelper.Stop();
}
}
}
}
//Step 12 - Complete any existing incomplete triples
if (!skip && newSubj != null)
{
foreach (IncompleteTriple t in context.IncompleteTriples)
{
if (t.Direction == IncompleteTripleDirection.Forward)
{
if (!context.Handler.HandleTriple(new Triple(context.ParentSubject, t.Predicate, newSubj)))
{
ParserHelper.Stop();
}
}
else
{
if (!context.Handler.HandleTriple(new Triple(newSubj, t.Predicate, context.ParentSubject)))
{
ParserHelper.Stop();
}
}
}
context.IncompleteTriples.Clear();
}
//Step 13 - Set up for processing child elements if necessary
//Can skip this if the next event is an end element
if (context.Events.Peek().EventType != Event.EndElement)
{
context.ParentSubject = newSubj;
if (currObjResource != null)
{
context.ParentObject = currObjResource;
}
else if (newSubj != null)
{
context.ParentObject = newSubj;
}
else
{
context.ParentObject = context.ParentSubject;
}
context.IncompleteTriples.AddRange(localIncompletes);
}
} while (context.Events.Count > 0);
if (context.Events.Count > 0)
{
throw new RdfParseException("Source document is malformed! Encountered an end element which closes the document element but there are still more elements to be parsed", current.Position);
}
context.Handler.EndRdf(true);
}
catch (RdfParsingTerminatedException)
{
context.Handler.EndRdf(true);
}
catch
{
context.Handler.EndRdf(false);
throw;
}
}
private INode UriToNode(RdfACoreParserContext context, Uri u)
{
if (u == null)
{
return null;
}
else if (u.Scheme.Equals("rdfa"))
{
String id = u.ToString().Substring(11);
if (id.Equals(String.Empty)) id = "rdfa-special-bnode";
return context.Handler.CreateBlankNode(id);
}
else
{
return context.Handler.CreateUriNode(u);
}
}
private Uri ParseUri(RdfACoreParserContext context, String value, RdfACurieMode mode)
{
switch (mode)
{
case RdfACurieMode.Uri:
//Resolve as a URI which may be relative
return this.ResolveUri(context, value);
case RdfACurieMode.SafeCurieOrCurieOrUri:
if (this.IsSafeCurie(value))
{
//If a Safe CURIE must resolve as a CURIE ignoring if not resolvable
return this.ResolveSafeCurie(context, value);
}
else
{
//Otherwise try resolving as a CURIE and if not resolvable try as a URI
Uri u = this.ResolveCurie(context, value);
if (u == null)
{
//Try resolving as a URI
return this.ResolveUri(context, value);
}
else
{
//Resolved as a CURIE
return u;
}
}
case RdfACurieMode.TermOrCurieOrAbsUri:
if (XmlSpecsHelper.IsNCName(value))
{
//If a Term try resolving as a term and ignore if not resolvable
return this.ResolveTerm(context, value);
}
else if (this.IsCurie(value))
{
//If a CURIE try resolving as a CURIE first
Uri u = this.ResolveCurie(context, value);
if (u == null)
{
//If not resolvable as a CURIE try as an absolute URI
return this.ResolveAbsoluteUri(value);
}
else
{
//Resolved as a CURIE
return u;
}
}
else
{
//Try resolving as an absolute URI
return this.ResolveAbsoluteUri(value);
}
default:
return null;
}
}
private INode ParseHrefAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return(this.UriToNode(context, this.ParseUri(context, evt["href"], RdfACurieMode.Uri)));
}
private String ParseTextContent(RdfACoreParserContext context)
{
int i = 1;
IRdfAEvent next;
StringBuilder output = new StringBuilder();
List<IRdfAEvent> events = new List<IRdfAEvent>();
do
{
next = context.Events.Dequeue();
switch (next.EventType)
{
case Event.Element:
i++;
break;
case Event.EndElement:
i--;
break;
case Event.Text:
output.Append(((TextEvent)next).Text);
break;
}
events.Add(next);
} while (i > 0);
foreach (IRdfAEvent evt in events)
{
context.Requeue(evt);
}
return output.ToString();
}
private Uri ParseUri(RdfACoreParserContext context, String value, RdfACurieMode mode)
{
switch (mode)
{
case RdfACurieMode.Uri:
//Resolve as a URI which may be relative
return(this.ResolveUri(context, value));
case RdfACurieMode.SafeCurieOrCurieOrUri:
if (this.IsSafeCurie(value))
{
//If a Safe CURIE must resolve as a CURIE ignoring if not resolvable
return(this.ResolveSafeCurie(context, value));
}
else
{
//Otherwise try resolving as a CURIE and if not resolvable try as a URI
Uri u = this.ResolveCurie(context, value);
if (u == null)
{
//Try resolving as a URI
return(this.ResolveUri(context, value));
}
else
{
//Resolved as a CURIE
return(u);
}
}
case RdfACurieMode.TermOrCurieOrAbsUri:
if (XmlSpecsHelper.IsNCName(value))
{
//If a Term try resolving as a term and ignore if not resolvable
return(this.ResolveTerm(context, value));
}
else if (this.IsCurie(value))
{
//If a CURIE try resolving as a CURIE first
Uri u = this.ResolveCurie(context, value);
if (u == null)
{
//If not resolvable as a CURIE try as an absolute URI
return(this.ResolveAbsoluteUri(value));
}
else
{
//Resolved as a CURIE
return(u);
}
}
else
{
//Try resolving as an absolute URI
return(this.ResolveAbsoluteUri(value));
}
default:
return(null);
}
}
private IEnumerable <Uri> ParseUris(RdfACoreParserContext context, String value)
{
String[] values = value.Trim().Split(this._whitespace);
return((from v in values
select this.ParseUri(context, value, RdfACurieMode.TermOrCurieOrAbsUri)).Where(u => u != null));
}
private IEnumerable <INode> ParsePropertyAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return(from u in this.ParseUris(context, evt["property"])
select this.UriToNode(context, u));
}
private INode ParseAboutAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return this.UriToNode(context, this.ParseUri(context, evt["about"], RdfACurieMode.SafeCurieOrCurieOrUri));
}
private INode ParseResourceAttibute(RdfACoreParserContext context, IRdfAEvent evt)
{
return(this.UriToNode(context, this.ParseUri(context, evt["resource"], RdfACurieMode.SafeCurieOrCurieOrUri)));
}
private INode ParseResourceAttibute(RdfACoreParserContext context, IRdfAEvent evt)
{
return this.UriToNode(context, this.ParseUri(context, evt["resource"], RdfACurieMode.SafeCurieOrCurieOrUri));
}
public virtual void ParseExtensions(RdfACoreParserContext context, IRdfAEvent evt)
{
}
private IEnumerable<INode> ParsePropertyAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
return (from u in this.ParseUris(context, evt["property"])
select this.UriToNode(context, u));
}
private bool ParseProfileAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
foreach (Uri u in this.ParseUris(context, evt["profile"]))
{
try
{
Graph g = new Graph();
#if !SILVERLIGHT
UriLoader.Load(g, u);
#else
throw new PlatformNotSupportedException("The @profile attribute is not currently supported under Silverlight/Windows Phone 7");
#endif
String prefixQuery = "PREFIX rdfa: <" + RdfAParser.RdfANamespace + "> SELECT SAMPLE(?prefix) AS ?NamespacePrefix SAMPLE(?uri) AS ?NamespaceURI WHERE { ?s rdfa:prefix ?prefix ; rdfa:uri ?uri } GROUP BY ?s HAVING (COUNT(?prefix) = 1 && COUNT(?uri) = 1)";
String termQuery = "PREFIX rdfa: <" + RdfAParser.RdfANamespace + "> SELECT SAMPLE(?term) AS ?Term SAMPLE(?uri) AS ?URI WHERE {?s rdfa:term ?term ; rdfa:uri ?uri } GROUP BY ?s HAVING (COUNT(?term) = 1 && COUNT(?uri) = 1)";
//Namespace Mappings
Object results = g.ExecuteQuery(prefixQuery);
if (results is SparqlResultSet)
{
SparqlResultSet rset = (SparqlResultSet)results;
foreach (SparqlResult r in rset.Results)
{
INode prefixNode = r["NamespacePrefix"];
INode nsNode = r["NamespaceURI"];
if (prefixNode.NodeType == NodeType.Literal && nsNode.NodeType == NodeType.Literal)
{
String prefix = ((ILiteralNode)prefixNode).Value.ToLower();
String ns = ((ILiteralNode)nsNode).Value;
context.Namespaces.AddNamespace(prefix, new Uri(ns));
}
}
}
//Term Mappings
results = g.ExecuteQuery(termQuery);
if (results is SparqlResultSet)
{
SparqlResultSet rset = (SparqlResultSet)results;
foreach (SparqlResult r in rset.Results)
{
INode termNode = r["Term"];
INode uriNode = r["URI"];
if (termNode.NodeType == NodeType.Literal && uriNode.NodeType == NodeType.Literal)
{
String term = ((ILiteralNode)termNode).Value;
String uri = ((ILiteralNode)uriNode).Value;
if (XmlSpecsHelper.IsNCName(term))
{
context.Terms.AddNamespace(term, new Uri(uri));
}
}
}
}
//Vocabulary Setting
INode vocabNode = g.GetTriplesWithPredicate(g.CreateUriNode(new Uri(RdfAParser.RdfANamespace + "vocabulary"))).Select(t => t.Object).FirstOrDefault();
if (vocabNode != null)
{
if (vocabNode.NodeType == NodeType.Literal)
{
context.DefaultVocabularyUri = new Uri(((ILiteralNode)vocabNode).Value);
}
else if (vocabNode.NodeType == NodeType.Uri)
{
context.DefaultVocabularyUri = ((IUriNode)vocabNode).Uri;
}
}
}
catch
{
return(false);
}
}
return(true);
}
private String ParseXmlContent(RdfACoreParserContext context)
{
int i = 1;
IRdfAEvent next;
Stack<String> openElements = new Stack<string>();
StringBuilder output = new StringBuilder();
do
{
next = context.Events.Peek();
switch (next.EventType)
{
case Event.Element:
i++;
output.Append("<" + ((ElementEvent)next).Name);
openElements.Push(((ElementEvent)next).Name);
foreach (KeyValuePair<String, String> attr in next.Attributes)
{
output.Append(" " + attr.Key + "=\"" + attr.Value + "\"");
}
context.Events.Dequeue();
if (context.Events.Peek().EventType == Event.EndElement)
{
context.Events.Dequeue();
i--;
output.Append(" />");
openElements.Pop();
}
else
{
output.Append(">");
}
continue;
case Event.EndElement:
i--;
if (i == 0)
{
break;
}
output.Append("</" + openElements.Pop() + ">");
break;
case Event.Text:
output.Append(((TextEvent)next).Text);
break;
}
context.Events.Dequeue();
} while (i > 0);
return output.ToString();
}
private Uri ResolveSafeCurie(RdfACoreParserContext context, String value)
{
return(this.ResolveCurie(context, value.Substring(1, value.Length - 2)));
}
private IEnumerable<Uri> ParseUris(RdfACoreParserContext context, String value)
{
String[] values = value.Trim().Split(this._whitespace);
return (from v in values
select this.ParseUri(context, value, RdfACurieMode.TermOrCurieOrAbsUri)).Where(u => u != null);
}
private Uri ResolveCurie(RdfACoreParserContext context, String value)
{
if (value.Contains(":"))
{
String prefix = value.Substring(0, value.IndexOf(':'));
String reference = (prefix.Length + 1 < value.Length ? value.Substring(value.IndexOf(':') + 1) : String.Empty);
if (prefix.Equals(String.Empty))
{
return new Uri(context.DefaultPrefixMapping.ToString() + reference);
}
else if (prefix.Equals("_"))
{
if (reference.Equals(String.Empty))
{
//Q: Should this throw an error?
if (context.SpecialBNodeSeen) return null;
context.SpecialBNodeSeen = true;
}
return new Uri("rdfa:bnode:" + reference);
}
else
{
if (context.Namespaces.HasNamespace(prefix))
{
return new Uri(context.Namespaces.GetNamespaceUri(prefix).ToString() + reference);
}
else
{
return null;
}
}
}
else
{
return null;
}
}
private Uri ResolveUri(RdfACoreParserContext context, String value)
{
try
{
String uri = Tools.ResolveUri(value, context.BaseUri.ToSafeString());
return new Uri(uri);
}
catch
{
return null;
}
}
private Uri ResolveTerm(RdfACoreParserContext context, String value)
{
if (context.Terms.HasNamespace(value))
{
return context.Terms.GetNamespaceUri(value);
}
else if (context.DefaultVocabularyUri != null)
{
return new Uri(context.DefaultVocabularyUri.ToString() + value);
}
else
{
return null;
}
}
private Uri ResolveSafeCurie(RdfACoreParserContext context, String value)
{
return this.ResolveCurie(context, value.Substring(1, value.Length - 2));
}
private void Parse(RdfACoreParserContext context)
{
try
{
context.Handler.StartRdf();
//Initialise Term Mappings
context.HostLanguage.InitTermMappings(context);
IRdfAEvent current;
bool first = true;
int nesting = 0;
INode rdfType = context.Handler.CreateUriNode(new Uri(RdfSpecsHelper.RdfType));
List<IncompleteTriple> localIncompletes = new List<IncompleteTriple>();
do
{
localIncompletes.Clear();
//Dequeue the next event and increment/decrement nesting as appropriate
current = context.Events.Dequeue();
switch (current.EventType)
{
case Event.Element:
nesting++;
context.IncrementNesting();
break;
case Event.EndElement:
context.DecrementNesting();
nesting--;
continue;
default:
//Otherwise skip the event and continue
continue;
//throw new RdfParseException("Encountered an unexpected event of type '" + current.GetType().ToString() + "' when an Element/End Element event was expected", current.Position);
}
//Stop when nesting level returns to 0
if (nesting == 0) break;
//Step 1 - Initialisation
bool skip = false;
INode newSubj = null, currObjResource = null, currObjLiteral = null;
//Before carrying out further steps allow host specific special actions
context.HostLanguage.ParseExtensions(context, current);
//Step 2 - @profile parsing
if (current.HasAttribute("profile"))
{
if (!this.ParseProfileAttribute(context, current))
{
//If an @profile attribute fails to parse then must ignore the current subtree
int i = 0;
IRdfAEvent next;
do
{
next = context.Events.Dequeue();
//Keep track of nesting in the subtree
if (next.EventType == Event.Element) i++;
if (next.EventType == Event.EndElement) i--;
} while (i > 0 && next.EventType != Event.EndElement && context.Events.Count > 0);
//If couldn't ignore a valid subtree then error
if (context.Events.Count == 0) throw new RdfParseException("Encountered an @profile attribute which pointed to a malformed profile which meant the relevant subtree of the document should be ignored but the document does not contain a well formed subtree");
//If a bad @profile then continue after we've ignored the subtree
continue;
}
}
//Step 3 - @vocab parsing
if (current.HasAttribute("vocab")) this.ParseVocabAttribute(context, current);
//Step 4 - @prefix parsing (plus any other mechanisms defined by the host language)
if (current.HasAttribute("prefix")) this.ParsePrefixAttribute(context, current);
context.HostLanguage.ParsePrefixMappings(context, current);
//Step 5 - Language parsing
context.HostLanguage.ParseLiteralLanguage(context, current);
if (!current.HasAttribute("rel") && !current.HasAttribute("rev"))
{
//Step 6 - If no @rel or @rev establish a subject
newSubj = this.ParseSubject(context, current, nesting == 1, out skip);
}
else
{
//Step 7 - Use @rel or @rev to establish a subject and an object resource
newSubj = this.ParseRelOrRevSubject(context, current, nesting == 1);
currObjResource = this.ParseObjectResource(context, current);
}
//Step 8 - If there is a non-null subject process @typeof
if (newSubj != null)
{
if (current.HasAttribute("typeof"))
{
foreach (INode n in this.ParseTypeofAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(newSubj, rdfType, n))) ParserHelper.Stop();
}
}
}
if (currObjResource != null)
{
//Step 9 - If there is a non-null object resource generate triples
if (current.HasAttribute("rel"))
{
foreach (INode n in this.ParseRelAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(newSubj, n, currObjResource))) ParserHelper.Stop();
}
}
if (current.HasAttribute("rev"))
{
foreach (INode n in this.ParseRevAttribute(context, current))
{
if (!context.Handler.HandleTriple(new Triple(currObjResource, n, newSubj))) ParserHelper.Stop();
}
}
}
else if (newSubj != null)
{
//Step 10 - If there is no object resource but there are predicates generate incomplete triples
currObjResource = context.Handler.CreateBlankNode();
if (current.HasAttribute("rel"))
{
foreach (INode n in this.ParseRelAttribute(context, current))
{
localIncompletes.Add(new IncompleteTriple(n, IncompleteTripleDirection.Forward));
}
}
if (current.HasAttribute("rev"))
{
foreach (INode n in this.ParseRevAttribute(context, current))
{
localIncompletes.Add(new IncompleteTriple(n, IncompleteTripleDirection.Reverse));
}
}
}
//Step 11 - Establish the current object literal
if (newSubj != null && current.HasAttribute("property"))
{
//Must be an @property attribute in order for any triples to be generated
List<INode> ps = this.ParsePropertyAttribute(context, current).ToList();
if (ps.Count > 0)
{
Uri dtUri;
if (current.HasAttribute("content"))
{
//If @content is present then either a plain/typed literal
if (current.HasAttribute("datatype"))
{
//@datatype is present so typed literal
dtUri = this.ParseUri(context, current["datatype"], RdfACurieMode.TermOrCurieOrAbsUri);
currObjLiteral = context.Handler.CreateLiteralNode(current["content"], dtUri);
}
else
{
//Plain literal
currObjLiteral = context.Handler.CreateLiteralNode(current["content"], context.Language);
}
}
else if (current.HasAttribute("datatype"))
{
//Typed literal
dtUri = this.ParseUri(context, current["datatype"], RdfACurieMode.TermOrCurieOrAbsUri);
if (dtUri != null)
{
if (dtUri.ToString().Equals(RdfSpecsHelper.RdfXmlLiteral))
{
//XML Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseXmlContent(context), dtUri);
}
else
{
//Typed Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), dtUri);
}
}
else
{
//If datatype does not resolve fall back to plain literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), context.Language);
}
}
else
{
//Plain Literal using element content
currObjLiteral = context.Handler.CreateLiteralNode(this.ParseTextContent(context), context.Language);
}
//Generate the relevant triples
foreach (INode p in ps)
{
if (!context.Handler.HandleTriple(new Triple(newSubj, p, currObjLiteral))) ParserHelper.Stop();
}
}
}
//Step 12 - Complete any existing incomplete triples
if (!skip && newSubj != null)
{
foreach (IncompleteTriple t in context.IncompleteTriples)
{
if (t.Direction == IncompleteTripleDirection.Forward)
{
if (!context.Handler.HandleTriple(new Triple(context.ParentSubject, t.Predicate, newSubj))) ParserHelper.Stop();
}
else
{
if (!context.Handler.HandleTriple(new Triple(newSubj, t.Predicate, context.ParentSubject))) ParserHelper.Stop();
}
}
context.IncompleteTriples.Clear();
}
//Step 13 - Set up for processing child elements if necessary
//Can skip this if the next event is an end element
if (context.Events.Peek().EventType != Event.EndElement)
{
context.ParentSubject = newSubj;
if (currObjResource != null)
{
context.ParentObject = currObjResource;
}
else if (newSubj != null)
{
context.ParentObject = newSubj;
}
else
{
context.ParentObject = context.ParentSubject;
}
context.IncompleteTriples.AddRange(localIncompletes);
}
} while (context.Events.Count > 0);
if (context.Events.Count > 0) throw new RdfParseException("Source document is malformed! Encountered an end element which closes the document element but there are still more elements to be parsed", current.Position);
context.Handler.EndRdf(true);
}
catch (RdfParsingTerminatedException)
{
context.Handler.EndRdf(true);
}
catch
{
context.Handler.EndRdf(false);
throw;
}
}
public virtual void InitTermMappings(RdfACoreParserContext context)
{
}
private bool ParseProfileAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
foreach (Uri u in this.ParseUris(context, evt["profile"]))
{
try
{
Graph g = new Graph();
#if !SILVERLIGHT
UriLoader.Load(g, u);
#else
throw new PlatformNotSupportedException("The @profile attribute is not currently supported under Silverlight/Windows Phone 7");
#endif
String prefixQuery = "PREFIX rdfa: <" + RdfAParser.RdfANamespace + "> SELECT SAMPLE(?prefix) AS ?NamespacePrefix SAMPLE(?uri) AS ?NamespaceURI WHERE { ?s rdfa:prefix ?prefix ; rdfa:uri ?uri } GROUP BY ?s HAVING (COUNT(?prefix) = 1 && COUNT(?uri) = 1)";
String termQuery = "PREFIX rdfa: <" + RdfAParser.RdfANamespace + "> SELECT SAMPLE(?term) AS ?Term SAMPLE(?uri) AS ?URI WHERE {?s rdfa:term ?term ; rdfa:uri ?uri } GROUP BY ?s HAVING (COUNT(?term) = 1 && COUNT(?uri) = 1)";
//Namespace Mappings
Object results = g.ExecuteQuery(prefixQuery);
if (results is SparqlResultSet)
{
SparqlResultSet rset = (SparqlResultSet)results;
foreach (SparqlResult r in rset.Results)
{
INode prefixNode = r["NamespacePrefix"];
INode nsNode = r["NamespaceURI"];
if (prefixNode.NodeType == NodeType.Literal && nsNode.NodeType == NodeType.Literal)
{
String prefix = ((ILiteralNode)prefixNode).Value.ToLower();
String ns = ((ILiteralNode)nsNode).Value;
context.Namespaces.AddNamespace(prefix, new Uri(ns));
}
}
}
//Term Mappings
results = g.ExecuteQuery(termQuery);
if (results is SparqlResultSet)
{
SparqlResultSet rset = (SparqlResultSet)results;
foreach (SparqlResult r in rset.Results)
{
INode termNode = r["Term"];
INode uriNode = r["URI"];
if (termNode.NodeType == NodeType.Literal && uriNode.NodeType == NodeType.Literal)
{
String term = ((ILiteralNode)termNode).Value;
String uri = ((ILiteralNode)uriNode).Value;
if (XmlSpecsHelper.IsNCName(term))
{
context.Terms.AddNamespace(term, new Uri(uri));
}
}
}
}
//Vocabulary Setting
INode vocabNode = g.GetTriplesWithPredicate(g.CreateUriNode(new Uri(RdfAParser.RdfANamespace + "vocabulary"))).Select(t => t.Object).FirstOrDefault();
if (vocabNode != null)
{
if (vocabNode.NodeType == NodeType.Literal)
{
context.DefaultVocabularyUri = new Uri(((ILiteralNode)vocabNode).Value);
}
else if (vocabNode.NodeType == NodeType.Uri)
{
context.DefaultVocabularyUri = ((IUriNode)vocabNode).Uri;
}
}
}
catch
{
return false;
}
}
return true;
}
public virtual void ParseLiteralLanguage(RdfACoreParserContext context, IRdfAEvent evt)
{
}
public override void InitTermMappings(RdfACoreParserContext context)
{
//TODO: Load the RDFa default terms
}
public override void InitTermMappings(RdfACoreParserContext context)
{
// TODO: Load RDFa default profile and HTML+RDFa profile
}
private INode ParseSubject(RdfACoreParserContext context, IRdfAEvent evt, bool isRoot, out bool skip)
{
skip = false;
if (evt.HasAttribute("about"))
{
return this.ParseAboutAttribute(context, evt);
}
else if (evt.HasAttribute("src"))
{
return this.ParseSrcAttribute(context, evt);
}
else if (evt.HasAttribute("resource"))
{
return this.ParseResourceAttibute(context, evt);
}
else if (evt.HasAttribute("href"))
{
return this.ParseHrefAttribute(context, evt);
}
else if (isRoot || context.HostLanguage.IsRootElement(evt))
{
return this.UriToNode(context, this.ParseUri(context, String.Empty, RdfACurieMode.SafeCurieOrCurieOrUri));
}
else if (evt.HasAttribute("typeof"))
{
return context.Handler.CreateBlankNode();
}
else
{
if (evt.HasAttribute("property")) skip = true;
return context.ParentObject;
}
}
public virtual void ParseExtensions(RdfACoreParserContext context, IRdfAEvent evt)
{
}
private INode ParseRelOrRevSubject(RdfACoreParserContext context, IRdfAEvent evt, bool isRoot)
{
if (evt.HasAttribute("about"))
{
return this.ParseAboutAttribute(context, evt);
}
else if (evt.HasAttribute("src"))
{
return this.ParseSrcAttribute(context, evt);
}
else if (isRoot || context.HostLanguage.IsRootElement(evt))
{
return this.UriToNode(context, this.ParseUri(context, String.Empty, RdfACurieMode.SafeCurieOrCurieOrUri));
}
else if (evt.HasAttribute("typeof"))
{
return context.Handler.CreateBlankNode();
}
else
{
return context.ParentObject;
}
}
public virtual void ParsePrefixMappings(RdfACoreParserContext context, IRdfAEvent evt)
{
}
private INode ParseObjectResource(RdfACoreParserContext context, IRdfAEvent evt)
{
if (evt.HasAttribute("resource"))
{
return this.ParseResourceAttibute(context, evt);
}
else if (evt.HasAttribute("href"))
{
return this.ParseHrefAttribute(context, evt);
}
else
{
return null;
}
}
private void ParseVocabAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
context.DefaultVocabularyUri = this.ParseUri(context, evt["vocab"], RdfACurieMode.Uri);
}
private void ParseVocabAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
context.DefaultVocabularyUri = this.ParseUri(context, evt["vocab"], RdfACurieMode.Uri);
}
private void ParsePrefixAttribute(RdfACoreParserContext context, IRdfAEvent evt)
{
String[] values = evt["prefix"].Split(this._whitespace);
for (int i = 0; i < values.Length - 1; i += 2)
{
String prefix = values[i];
Uri uri = this.ResolveAbsoluteUri(values[i + 1]);
if (uri == null) continue;
context.Namespaces.AddNamespace(prefix, uri);
}
}
public override void InitTermMappings(RdfACoreParserContext context)
{
//TODO: Load RDFa default profile and HTML+RDFa profile
}
