/// <summary>
/// Delete triple with specified parameters.
/// </summary>
/// <param name="subjectName">Subject</param>
/// <param name="predicateName">Predicate</param>
/// <param name="objectName">Object</param>
/// <returns>Returns 'True' if operation completed succeful, 'False' otherwise.</returns>
public bool DeleteTriplet(TripleName subjectName, TripleName predicateName, TripleName objectName)
{
subjectName = EnsurePrefix(subjectName);
predicateName = EnsurePrefix(predicateName);
objectName = EnsurePrefix(objectName);
var shortSubjectStr = subjectName.ToString();
var shortPredicateStr = predicateName.ToString();
var shortObjectStr = objectName.ToString();
var tr = Triples.Where(t => t.Subject == shortSubjectStr && t.Predicate == shortPredicateStr).Include(o => o.Objects).FirstOrDefault();
if (tr != null)
{
var obj = tr.Objects.FirstOrDefault(o => o.Object == shortObjectStr);
if (obj != null)
{
TripleObjects.Remove(TripleObjects.Find(obj.TripleObject_Id));
if (!tr.Objects.Any())
Triples.Remove(tr);
SaveChanges();
return true;
}
}
return false;
}
/// <summary>Build list of triples that reference specified object</summary>
/// <param name="predicate">Optional predicate name</param>
/// <param name="obj">Object full name</param>
/// <returns>List of triples</returns>
public List <Triple> GetIncomingTriplets(string predicate, string obj)
{
var objectName = EnsurePrefix(TripleName.Parse(obj)).ToString();
IQueryable <Triple> triples;
if (!String.IsNullOrEmpty(predicate))
{
var predicateName = EnsurePrefix(TripleName.Parse(predicate)).ToString();
triples = Triples.Where(t => t.Predicate == predicateName);
}
else
{
// Not very efficient as it enumerates entire database
triples = Triples;
}
return(triples.
Include(o => o.Objects). // Include Objects collection
Where(t => t.Objects.Any(o => o.Object == objectName)).
ToArray(). // Stop LINQ to SQL and use simple collection transformations
Select(t => new Triple {
Subject = t.Subject,
Predicate = t.Predicate,
Objects = new Collection <TripleObject>(t.Objects.Where(o => o.Object == objectName).ToArray())
}).ToList());
}
/// <summary>
/// Delete triple with specified parameters.
/// </summary>
/// <param name="subjectName">Subject</param>
/// <param name="predicateName">Predicate</param>
/// <param name="objectName">Object</param>
/// <returns>Returns 'True' if operation completed succeful, 'False' otherwise.</returns>
public bool DeleteTriplet(TripleName subjectName, TripleName predicateName, TripleName objectName)
{
subjectName = EnsurePrefix(subjectName);
predicateName = EnsurePrefix(predicateName);
objectName = EnsurePrefix(objectName);
var shortSubjectStr = subjectName.ToString();
var shortPredicateStr = predicateName.ToString();
var shortObjectStr = objectName.ToString();
var tr = Triples.Where(t => t.Subject == shortSubjectStr && t.Predicate == shortPredicateStr).Include(o => o.Objects).FirstOrDefault();
if (tr != null)
{
var obj = tr.Objects.FirstOrDefault(o => o.Object == shortObjectStr);
if (obj != null)
{
TripleObjects.Remove(TripleObjects.Find(obj.TripleObject_Id));
if (!tr.Objects.Any())
{
Triples.Remove(tr);
}
SaveChanges();
return(true);
}
}
return(false);
}
/// <summary>Ensures that triple name has prefix. If triple name has namespace, it is converted to prefix</summary>
/// <param name="name">Name of the triple</param>
/// <returns>Name of the triple with prefix available</returns>
public TripleName EnsurePrefix(TripleName name)
{
if(name.Prefix == null) {
var found = TripleName.PrefixesAndNamespaces.FirstOrDefault(p => p.Value == name.Namespace );
if (found.Key != null)
return new TripleName(name.Namespace, found.Key, name.Name);
var tr = TriplePrefixes.FirstOrDefault(t => t.Namespace == name.Namespace);
if(tr != null)
return new TripleName(name.Namespace, tr.Prefix, name.Name);
else
throw new ArgumentException(String.Format("There is no known prefix for namespace {0}", name.Namespace));
} else
return name;
}
/// <summary>
/// Add triple with specified parameters.
/// </summary>
/// <param name="subjectStr">Subject</param>
/// <param name="predicateStr">Predicate</param>
/// <param name="objectStr">Object</param>
/// <returns>Returns 'True' if operation completed succeful, 'False' otherwise.</returns>
/// <example>PutTriplet( “czusr:76087518-4f8e-4d3a-9bfb-2fd2332376eb”, “czpred:favorite”, "cztimeline:3a87bb5c-85f7-4305-8b2f-f2002580cd25")</example>
public bool PutTriplet(TripleName subjectName, TripleName predicateName, TripleName objectName)
{
subjectName = EnsurePrefix(subjectName);
predicateName = EnsurePrefix(predicateName);
objectName = EnsurePrefix(objectName);
var shortSubjectStr = subjectName.ToString();
var shortPredicateStr = predicateName.ToString();
var shortObjectStr = objectName.ToString();
var tr = Triples.Where(t => t.Subject == shortSubjectStr && t.Predicate == shortPredicateStr).Include(o => o.Objects).FirstOrDefault();
if (tr != null)
{
if (tr.Objects.FirstOrDefault(x => x.Object == shortObjectStr) == null)
{
tr.Objects.Add(
new TripleObject
{
Object = shortObjectStr,
TripleObject_Id = Guid.NewGuid()
}
);
}
else
{
return(true);
}
SaveChanges();
return(true);
}
var triple = new Triple
{
Subject = shortSubjectStr,
Predicate = shortPredicateStr,
Id = Guid.NewGuid(),
Objects = new Collection <TripleObject>
{
new TripleObject
{
Object = shortObjectStr,
TripleObject_Id = Guid.NewGuid()
}
}
};
Triples.Add(triple);
SaveChanges();
return(true);
}
public TripleName TryEnsureNamespace(TripleName name)
{
if (name.Namespace == null)
{
if (TripleName.PrefixesAndNamespaces.ContainsKey(name.Prefix))
{
return(new TripleName(TripleName.PrefixesAndNamespaces[name.Prefix], name.Prefix, name.Name));
}
var tr = TriplePrefixes.FirstOrDefault(x => x.Prefix == name.Prefix);
return(tr != null ? new TripleName(tr.Namespace, name.Prefix, name.Name) : name);
}
else
{
return(name);
}
}
/// <summary>
/// Get triple by specified parameters.
/// </summary>
/// <param name="subject">Subject name with prefix</param>
/// <param name="predicate">Predicate name with prefix or null</param>
/// <param name="obj">Object name with prefix or null</param>
/// <param name="expandPrefixes">If 'True' returns namespaces, else - prefixes.</param>
/// <returns>Returns list of triplets.</returns>
/// <example>GetTriplet( “czusr:76087518-4f8e-4d3a-9bfb-2fd2332376eb”, “czpred:favorite”, null, false)</example>
public List <Triple> GetTriplet(string subject, string predicate = null, string obj = null, bool expandPrefixes = false)
{
if (subject == null)
{
throw new ArgumentNullException("subject");
}
var subjectName = EnsurePrefix(TripleName.Parse(subject));
string subjectStr = subjectName.ToString();
IQueryable <Triple> triples;
if (predicate != null)
{
var predicateName = EnsurePrefix(TripleName.Parse(predicate));
var predicateStr = predicateName.ToString();
if (obj != null)
{
var objectName = EnsurePrefix(TripleName.Parse(obj));
var objectStr = objectName.ToString();
triples = Triples.Where(t => t.Subject == subjectStr && t.Predicate == predicateStr).Include(o => o.Objects).Where(t => t.Objects.FirstOrDefault(x => x.Object == objectStr) != null);
}
else
{
triples = Triples.Where(t => t.Subject == subjectStr && t.Predicate == predicateStr).Include(o => o.Objects);
}
}
else
{
triples = Triples.Where(t => t.Subject == subjectStr).Include(o => o.Objects);
}
if (expandPrefixes)
{
//ToDo:Use Join
triples.ToList().ForEach(x =>
{
x.Subject = TryEnsureNamespace(TripleName.Parse(x.Subject)).ToExpandedString();
x.Predicate = TryEnsureNamespace(TripleName.Parse(x.Predicate)).ToExpandedString();
foreach (var o in x.Objects)
{
o.Object = TryEnsureNamespace(TripleName.Parse(o.Object)).ToExpandedString();
}
});
}
return(triples.ToList());
}
/// <summary>Ensures that triple name has prefix. If triple name has namespace, it is converted to prefix</summary>
/// <param name="name">Name of the triple</param>
/// <returns>Name of the triple with prefix available</returns>
public TripleName EnsurePrefix(TripleName name)
{
if (name.Prefix == null)
{
var found = TripleName.PrefixesAndNamespaces.FirstOrDefault(p => p.Value == name.Namespace);
if (found.Key != null)
{
return(new TripleName(name.Namespace, found.Key, name.Name));
}
var tr = TriplePrefixes.FirstOrDefault(t => t.Namespace == name.Namespace);
if (tr != null)
{
return(new TripleName(name.Namespace, tr.Prefix, name.Name));
}
else
{
throw new ArgumentException(String.Format("There is no known prefix for namespace {0}", name.Namespace));
}
}
else
{
return(name);
}
}
/// <summary>Gets owner of the triplet</summary>
/// <param name="name">Name of the triplet. Triplets referring to timelines, exhibits, artifacts and bNodes are supported.
/// In all other cases method returns null.</param>
/// <param name="bNodes">List of previously examined bNodes to avoid endless recursion</param>
/// <returns>String representation of owning user ID</returns>
public string GetSubjectOwner(TripleName name, List<string> bNodes = null)
{
name = EnsurePrefix(name);
switch (name.Prefix)
{
case TripleName.UserPrefix:
return name.Name;
case TripleName.TimelinePrefix:
var timelineId = Guid.Parse(name.Name);
var timeline = Timelines.Where(t => t.Id == timelineId).FirstOrDefault();
if (timeline == null)
return null;
Entry(timeline).Reference(t => t.Collection).Load();
return GetCollectionOwner(timeline.Collection);
case TripleName.ExhibitPrefix:
var exhibitId = Guid.Parse(name.Name);
var exhibit = Exhibits.Where(e => e.Id == exhibitId).FirstOrDefault();
if (exhibit == null)
return null;
Entry(exhibit).Reference(e => e.Collection).Load();
return GetCollectionOwner(exhibit.Collection);
case TripleName.ArtifactPrefix:
var artifactId = Guid.Parse(name.Name);
var artifact = ContentItems.Where(c => c.Id == artifactId).FirstOrDefault();
if (artifact == null)
return null;
Entry(artifact).Reference(a => a.Collection).Load();
return GetCollectionOwner(artifact.Collection);
case TripleName.TourPrefix:
var tourId = Guid.Parse(name.Name);
var tour = Tours.FirstOrDefault(t => t.Id == tourId);
if (tour == null)
return null;
Entry(tour).Reference(t => t.Collection).Load();
return GetCollectionOwner(tour.Collection);
case "_":
var subject = name.ToString();
// Guard against infinite loop
if (bNodes != null && bNodes.Contains(subject))
return null;
// Find subject of any triple that uses passed subject as object
var linkedSubject = Triples.
Include(t => t.Objects).
Where(t => t.Objects.Any(o => o.Object == subject)).
Select(t => t.Subject).FirstOrDefault();
if (String.IsNullOrEmpty(linkedSubject))
return null;
// Get owner of linked subject
if (bNodes == null)
bNodes = new List<string>(new string[] { subject });
else
bNodes.Add(subject);
return GetSubjectOwner(TripleName.Parse(linkedSubject), bNodes);
default:
return null;
}
}
/// <summary>Gets owner of the triplet</summary>
/// <param name="name">Name of the triplet. Triplets referring to timelines, exhibits, artifacts and bNodes are supported.
/// In all other cases method returns null.</param>
/// <param name="bNodes">List of previously examined bNodes to avoid endless recursion</param>
/// <returns>String representation of owning user ID</returns>
public string GetSubjectOwner(TripleName name, List <string> bNodes = null)
{
name = EnsurePrefix(name);
switch (name.Prefix)
{
case TripleName.UserPrefix:
return(name.Name);
case TripleName.TimelinePrefix:
var timelineId = Guid.Parse(name.Name);
var timeline = Timelines.Where(t => t.Id == timelineId).FirstOrDefault();
if (timeline == null)
{
return(null);
}
Entry(timeline).Reference(t => t.Collection).Load();
return(GetCollectionOwner(timeline.Collection));
case TripleName.ExhibitPrefix:
var exhibitId = Guid.Parse(name.Name);
var exhibit = Exhibits.Where(e => e.Id == exhibitId).FirstOrDefault();
if (exhibit == null)
{
return(null);
}
Entry(exhibit).Reference(e => e.Collection).Load();
return(GetCollectionOwner(exhibit.Collection));
case TripleName.ArtifactPrefix:
var artifactId = Guid.Parse(name.Name);
var artifact = ContentItems.Where(c => c.Id == artifactId).FirstOrDefault();
if (artifact == null)
{
return(null);
}
Entry(artifact).Reference(a => a.Collection).Load();
return(GetCollectionOwner(artifact.Collection));
case TripleName.TourPrefix:
var tourId = Guid.Parse(name.Name);
var tour = Tours.FirstOrDefault(t => t.Id == tourId);
if (tour == null)
{
return(null);
}
Entry(tour).Reference(t => t.Collection).Load();
return(GetCollectionOwner(tour.Collection));
case "_":
var subject = name.ToString();
// Guard against infinite loop
if (bNodes != null && bNodes.Contains(subject))
{
return(null);
}
// Find subject of any triple that uses passed subject as object
var linkedSubject = Triples.
Include(t => t.Objects).
Where(t => t.Objects.Any(o => o.Object == subject)).
Select(t => t.Subject).FirstOrDefault();
if (String.IsNullOrEmpty(linkedSubject))
{
return(null);
}
// Get owner of linked subject
if (bNodes == null)
{
bNodes = new List <string>(new string[] { subject });
}
else
{
bNodes.Add(subject);
}
return(GetSubjectOwner(TripleName.Parse(linkedSubject), bNodes));
default:
return(null);
}
}
public TripleName TryEnsureNamespace(TripleName name)
{
if(name.Namespace == null)
{
if (TripleName.PrefixesAndNamespaces.ContainsKey(name.Prefix))
return new TripleName(TripleName.PrefixesAndNamespaces[name.Prefix], name.Prefix, name.Name);
var tr = TriplePrefixes.FirstOrDefault(x => x.Prefix == name.Prefix);
return tr != null ? new TripleName(tr.Namespace, name.Prefix, name.Name) : name;
} else
return name;
}
/// <summary>
/// Add triple with specified parameters.
/// </summary>
/// <param name="subjectStr">Subject</param>
/// <param name="predicateStr">Predicate</param>
/// <param name="objectStr">Object</param>
/// <returns>Returns 'True' if operation completed succeful, 'False' otherwise.</returns>
/// <example>PutTriplet( “czusr:76087518-4f8e-4d3a-9bfb-2fd2332376eb”, “czpred:favorite”, "cztimeline:3a87bb5c-85f7-4305-8b2f-f2002580cd25")</example>
public bool PutTriplet(TripleName subjectName, TripleName predicateName, TripleName objectName)
{
subjectName = EnsurePrefix(subjectName);
predicateName = EnsurePrefix(predicateName);
objectName = EnsurePrefix(objectName);
var shortSubjectStr = subjectName.ToString();
var shortPredicateStr = predicateName.ToString();
var shortObjectStr = objectName.ToString();
var tr = Triples.Where(t => t.Subject == shortSubjectStr && t.Predicate == shortPredicateStr).Include(o => o.Objects).FirstOrDefault();
if (tr != null)
{
if (tr.Objects.FirstOrDefault(x => x.Object == shortObjectStr) == null)
{
tr.Objects.Add(
new TripleObject
{
Object = shortObjectStr,
TripleObject_Id = Guid.NewGuid()
}
);
}
else
{
return true;
}
SaveChanges();
return true;
}
var triple = new Triple
{
Subject = shortSubjectStr,
Predicate = shortPredicateStr,
Id = Guid.NewGuid(),
Objects = new Collection<TripleObject>
{
new TripleObject
{
Object = shortObjectStr,
TripleObject_Id = Guid.NewGuid()
}
}
};
Triples.Add(triple);
SaveChanges();
return true;
}
