/// <summary>
/// Processes an INSERT command
/// </summary>
/// <param name="cmd">Insert Command</param>
/// <remarks>
/// <para>
/// <strong>Note:</strong> The underlying manager must implement the <see cref="IQueryableGenericIOManager">IQueryableGenericIOManager</see> interface in order for INSERT commands to be processed
/// </para>
/// </remarks>
public void ProcessInsertCommand(InsertCommand cmd)
{
if (this._manager is IUpdateableGenericIOManager)
{
((IUpdateableGenericIOManager)this._manager).Update(cmd.ToString());
}
else
{
if (this._manager is IQueryableGenericIOManager)
{
//Check IO Behaviour
//For a insert we either need the ability to Update Add Triples or to Overwrite Graphs
//Firstly check behaviour persuant to default graph if applicable
if (cmd.InsertPattern.TriplePatterns.OfType<IConstructTriplePattern>().Any())
{
//Must support notion of default graph
if ((this._manager.IOBehaviour & IOBehaviour.HasDefaultGraph) == 0) throw new SparqlUpdateException("The underlying store does not support the notion of an explicit unnamed Default Graph required to process this command");
//Must allow either OverwriteDefault or CanUpdateAddTriples
if ((this._manager.IOBehaviour & IOBehaviour.CanUpdateAddTriples) == 0 && (this._manager.IOBehaviour & IOBehaviour.OverwriteDefault) == 0) throw new SparqlUpdateException("The underlying store does not support the required IO Behaviour to implement this command");
}
//Then check behaviour persuant to named graphs if applicable
if (cmd.InsertPattern.HasChildGraphPatterns)
{
//Must support named graphs
if ((this._manager.IOBehaviour & IOBehaviour.HasNamedGraphs) == 0) throw new SparqlUpdateException("The underlying store does not support the notion of named graphs required to process this command");
//Must allow either CanUpdateAddTriples or OverwriteNamed
if ((this._manager.IOBehaviour & IOBehaviour.CanUpdateAddTriples) == 0 && (this._manager.IOBehaviour & IOBehaviour.OverwriteNamed) == 0) throw new SparqlUpdateException("The underlying store does not support the required IO Behaviour to implement this command");
}
//First build and make the query to get a Result Set
String queryText = "SELECT * WHERE " + cmd.WherePattern.ToString();
SparqlQueryParser parser = new SparqlQueryParser();
SparqlQuery query = parser.ParseFromString(queryText);
if (cmd.GraphUri != null && !cmd.UsingUris.Any()) query.AddDefaultGraph(cmd.GraphUri);
foreach (Uri u in cmd.UsingUris)
{
query.AddDefaultGraph(u);
}
foreach (Uri u in cmd.UsingNamedUris)
{
query.AddNamedGraph(u);
}
Object results = ((IQueryableGenericIOManager)this._manager).Query(query.ToString());
if (results is SparqlResultSet)
{
//Now need to transform the Result Set back to a Multiset
Multiset mset = new Multiset((SparqlResultSet)results);
//Generate the Triples for each Solution
List<Triple> insertedTriples = new List<Triple>();
Dictionary<String, List<Triple>> insertedGraphTriples = new Dictionary<string, List<Triple>>();
foreach (ISet s in mset.Sets)
{
List<Triple> tempInsertedTriples = new List<Triple>();
try
{
ConstructContext context = new ConstructContext(null, s, true);
foreach (IConstructTriplePattern p in cmd.InsertPattern.TriplePatterns.OfType<IConstructTriplePattern>())
{
try
{
tempInsertedTriples.Add(p.Construct(context));
}
catch (RdfQueryException)
{
//If we get an error here then it means we couldn't construct a specific
//triple so we continue anyway
}
}
insertedTriples.AddRange(tempInsertedTriples);
}
catch (RdfQueryException)
{
//If we get an error here this means we couldn't construct for this solution so the
//solution is ignore for this graph
}
//Triples from GRAPH clauses
foreach (GraphPattern gp in cmd.InsertPattern.ChildGraphPatterns)
{
tempInsertedTriples.Clear();
try
{
String graphUri;
switch (gp.GraphSpecifier.TokenType)
{
case Token.URI:
graphUri = gp.GraphSpecifier.Value;
break;
case Token.VARIABLE:
if (s.ContainsVariable(gp.GraphSpecifier.Value))
{
INode temp = s[gp.GraphSpecifier.Value.Substring(1)];
if (temp == null)
{
//If the Variable is not bound then skip
continue;
}
else if (temp.NodeType == NodeType.Uri)
{
graphUri = temp.ToSafeString();
}
else
{
//If the Variable is not bound to a URI then skip
continue;
}
}
else
{
//If the Variable is not bound for this solution then skip
continue;
}
break;
default:
//Any other Graph Specifier we have to ignore this solution
continue;
}
if (!insertedGraphTriples.ContainsKey(graphUri)) insertedGraphTriples.Add(graphUri, new List<Triple>());
ConstructContext context = new ConstructContext(null, s, true);
foreach (IConstructTriplePattern p in gp.TriplePatterns.OfType<IConstructTriplePattern>())
{
try
{
tempInsertedTriples.Add(p.Construct(context));
}
catch (RdfQueryException)
{
//If we get an error here then it means we couldn't construct a specific
//triple so we continue anyway
}
}
insertedGraphTriples[graphUri].AddRange(tempInsertedTriples);
}
catch (RdfQueryException)
{
//If we get an error here this means we couldn't construct for this solution so the
//solution is ignore for this graph
}
}
}
//Now decide how to apply the update
if (this._manager.UpdateSupported)
{
this._manager.UpdateGraph(cmd.GraphUri, insertedTriples, Enumerable.Empty<Triple>());
foreach (KeyValuePair<String, List<Triple>> graphInsertion in insertedGraphTriples)
{
this._manager.UpdateGraph(graphInsertion.Key, graphInsertion.Value, Enumerable.Empty<Triple>());
}
}
else
{
Graph g = new Graph();
this._manager.LoadGraph(g, cmd.GraphUri);
g.Assert(insertedTriples);
this._manager.SaveGraph(g);
foreach (KeyValuePair<String, List<Triple>> graphInsertion in insertedGraphTriples)
{
g = new Graph();
this._manager.LoadGraph(g, graphInsertion.Key);
g.Assert(graphInsertion.Value);
this._manager.SaveGraph(g);
}
}
}
else
{
throw new SparqlUpdateException("Cannot evaluate an INSERT Command as the underlying Store failed to answer the query for the WHERE portion of the command as expected");
}
}
else
{
throw new NotSupportedException("INSERT commands are not supported by this Update Processor as the manager for the underlying Store does not provide Query capabilities which are necessary to process this command");
}
}
}
