|
public static Parse ( string name ) : |
||
| name | string | String with full triple name |
| return | ||
/// <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>
/// 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>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);
}
}
