public void SparqlUpdateCreateDrop()
{
TripleStore store = new TripleStore();
Console.WriteLine("Store has " + store.Graphs.Count + " Graphs");
//Create a couple of Graphs using Create Commands
CreateCommand create1 = new CreateCommand(new Uri("http://example.org/1"));
CreateCommand create2 = new CreateCommand(new Uri("http://example.org/2"));
store.ExecuteUpdate(create1);
store.ExecuteUpdate(create2);
Assert.AreEqual(3, store.Graphs.Count, "Store should have now had three Graphs");
Assert.AreEqual(0, store.Triples.Count(), "Store should have no triples at this point");
//Trying the same Create again should cause an error
try
{
store.ExecuteUpdate(create1);
Assert.Fail("Executing a CREATE command twice without the SILENT modifier should error");
}
catch (SparqlUpdateException)
{
Console.WriteLine("Executing a CREATE command twice without the SILENT modifier errored as expected");
}
//Equivalent Create with SILENT should not error
CreateCommand create3 = new CreateCommand(new Uri("http://example.org/1"), true);
try
{
store.ExecuteUpdate(create3);
Console.WriteLine("Executing a CREATE for an existing Graph with the SILENT modifier suppressed the error as expected");
}
catch (SparqlUpdateException)
{
Assert.Fail("Executing a CREATE for an existing Graph with the SILENT modifier should not error");
}
DropCommand drop1 = new DropCommand(new Uri("http://example.org/1"));
store.ExecuteUpdate(drop1);
Assert.AreEqual(2, store.Graphs.Count, "Store should have only 2 Graphs after we executed the DROP command");
try
{
store.ExecuteUpdate(drop1);
Assert.Fail("Trying to DROP a non-existent Graph should error");
}
catch (SparqlUpdateException)
{
Console.WriteLine("Trying to DROP a non-existent Graph produced an error as expected");
}
DropCommand drop2 = new DropCommand(new Uri("http://example.org/1"), ClearMode.Graph, true);
try
{
store.ExecuteUpdate(drop2);
Console.WriteLine("Trying to DROP a non-existent Graph with the SILENT modifier suppressed the error as expected");
}
catch (SparqlUpdateException)
{
Assert.Fail("Trying to DROP a non-existent Graph with the SILENT modifier should suppress the error");
}
}
/// <summary>
/// Processes a CREATE command
/// </summary>
/// <param name="cmd">Create Command</param>
public void ProcessCreateCommand(CreateCommand cmd)
{
this.ProcessCommand(cmd);
}
/// <summary>
/// Processes a CREATE command
/// </summary>
/// <param name="cmd">Create Command</param>
/// <remarks>
/// <para>
/// Implemented by adding an empty Graph to the Store
/// </para>
/// <para>
/// <strong>Warning:</strong> As the <see cref="IGenericIOManager">IGenericIOManager</see> interface does not allow checking whether a Graph exists processing CREATE commands can result in overwriting existing Graphs
/// </para>
/// </remarks>
public void ProcessCreateCommand(CreateCommand cmd)
{
if (this._manager is IUpdateableGenericIOManager)
{
((IUpdateableGenericIOManager)this._manager).Update(cmd.ToString());
}
else
{
Graph g = new Graph();
g.BaseUri = cmd.TargetUri;
try
{
//As Khalil Ahmed pointed out the behaviour when the store doesn't support empty graphs the behaviour should be to act as if the operation succeeded
if ((this._manager.IOBehaviour & IOBehaviour.ExplicitEmptyGraphs) == 0) return;
this._manager.SaveGraph(g);
}
catch
{
if (!cmd.Silent) throw;
}
}
}
/// <summary>
/// Processes a CREATE command
/// </summary>
/// <param name="cmd">Create Command</param>
/// <remarks>
/// <para>
/// Implemented by adding an empty Graph to the Store
/// </para>
/// <para>
/// <strong>Warning:</strong> As the <see cref="IGenericIOManager">IGenericIOManager</see> interface does not allow checking whether a Graph exists processing CREATE commands can result in overwriting existing Graphs
/// </para>
/// </remarks>
public void ProcessCreateCommand(CreateCommand cmd)
{
if (this._manager is IUpdateableGenericIOManager)
{
((IUpdateableGenericIOManager)this._manager).Update(cmd.ToString());
}
else
{
Graph g = new Graph();
g.BaseUri = cmd.TargetUri;
try
{
this._manager.SaveGraph(g);
}
catch
{
if (!cmd.Silent) throw;
}
}
}
/// <summary>
/// Processes a CREATE command
/// </summary>
/// <param name="cmd">Create Command</param>
/// <param name="context">SPARQL Update Evaluation Context</param>
protected virtual void ProcessCreateCommandInternal(CreateCommand cmd, SparqlUpdateEvaluationContext context)
{
cmd.Evaluate(context);
}
/// <summary>
/// Processes a CREATE command
/// </summary>
/// <param name="cmd">Create Command</param>
public void ProcessCreateCommand(CreateCommand cmd)
{
this.ProcessCreateCommandInternal(cmd, this.GetContext());
}
private void TryParseCreateCommand(SparqlUpdateParserContext context)
{
bool silent = false;
//May possibly have a SILENT Keyword
IToken next = context.Tokens.Dequeue();
if (next.TokenType == Token.SILENT)
{
silent = true;
next = context.Tokens.Dequeue();
}
//Followed by a mandatory GRAPH Keyword
if (next.TokenType != Token.GRAPH)
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a GRAPH Keyword as part of the CREATE command", next);
}
//Then MUST have a URI
Uri u = this.TryParseGraphRef(context);
CreateCommand cmd = new CreateCommand(u, silent);
context.CommandSet.AddCommand(cmd);
}
