/// <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>
/// 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>
/// 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);
}
/// <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);
}
}
/// <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;
}
