/// <summary>
/// Helper function which returns the Results (Graph/Triple Store/SPARQL Results) back to the Client in one of their accepted formats
/// </summary>
/// <param name="context">Context of the HTTP Request</param>
/// <param name="result">Results of the Sparql Query</param>
/// <param name="config">Handler Configuration</param>
public static void SendToClient(HttpContext context, Object result, BaseHandlerConfiguration config)
{
MimeTypeDefinition definition = null;
String ctype = "text/plain";
String[] acceptTypes = HandlerHelper.GetAcceptTypes(context);
//Return the Results
if (result is SparqlResultSet)
{
ISparqlResultsWriter sparqlWriter = null;
//Try and get a MIME Type Definition using the HTTP Requests Accept Header
if (acceptTypes != null)
{
definition = MimeTypesHelper.GetDefinitions(acceptTypes).FirstOrDefault(d => d.CanWriteSparqlResults);
}
//Try and get the registered Definition for SPARQL Results XML
if (definition == null)
{
definition = MimeTypesHelper.GetDefinitions(MimeTypesHelper.SparqlXml[0]).FirstOrDefault();
}
//If Definition is still null create a temporary definition
if (definition == null)
{
definition = new MimeTypeDefinition("SPARQL Results XML", MimeTypesHelper.SparqlXml, Enumerable.Empty <String>());
definition.SparqlResultsWriterType = typeof(VDS.RDF.Writing.SparqlXmlWriter);
}
//Set up the Writer appropriately
sparqlWriter = definition.GetSparqlResultsWriter();
context.Response.ContentType = definition.CanonicalMimeType;
HandlerHelper.ApplyWriterOptions(sparqlWriter, config);
//Clear any existing Response
context.Response.Clear();
//Send Result Set to Client
context.Response.ContentEncoding = definition.Encoding;
sparqlWriter.Save((SparqlResultSet)result, new StreamWriter(context.Response.OutputStream, definition.Encoding));
}
else if (result is IGraph)
{
IRdfWriter rdfWriter = null;
//Try and get a MIME Type Definition using the HTTP Requests Accept Header
if (acceptTypes != null)
{
definition = MimeTypesHelper.GetDefinitions(acceptTypes).FirstOrDefault(d => d.CanWriteRdf);
}
if (definition == null)
{
//If no appropriate definition then use the GetWriter method instead
rdfWriter = MimeTypesHelper.GetWriter(acceptTypes, out ctype);
}
else
{
rdfWriter = definition.GetRdfWriter();
}
//Setup the writer
if (definition != null)
{
ctype = definition.CanonicalMimeType;
}
context.Response.ContentType = ctype;
HandlerHelper.ApplyWriterOptions(rdfWriter, config);
//Clear any existing Response
context.Response.Clear();
//Send Graph to Client
if (definition != null)
{
context.Response.ContentEncoding = definition.Encoding;
rdfWriter.Save((IGraph)result, new StreamWriter(context.Response.OutputStream, definition.Encoding));
}
else
{
rdfWriter.Save((IGraph)result, new StreamWriter(context.Response.OutputStream));
}
}
else if (result is ITripleStore)
{
IStoreWriter storeWriter = null;
//Try and get a MIME Type Definition using the HTTP Requests Accept Header
if (acceptTypes != null)
{
definition = MimeTypesHelper.GetDefinitions(acceptTypes).FirstOrDefault(d => d.CanWriteRdfDatasets);
}
if (definition == null)
{
//If no appropriate definition then use the GetStoreWriter method instead
storeWriter = MimeTypesHelper.GetStoreWriter(acceptTypes, out ctype);
}
else
{
storeWriter = definition.GetRdfDatasetWriter();
}
//Setup the writer
if (definition != null)
{
ctype = definition.CanonicalMimeType;
}
context.Response.ContentType = ctype;
HandlerHelper.ApplyWriterOptions(storeWriter, config);
//Clear any existing Response
context.Response.Clear();
//Send Triple Store to Client
if (definition != null)
{
context.Response.ContentEncoding = definition.Encoding;
storeWriter.Save((ITripleStore)result, new VDS.RDF.Storage.Params.StreamParams(context.Response.OutputStream, definition.Encoding));
}
else
{
storeWriter.Save((ITripleStore)result, new VDS.RDF.Storage.Params.StreamParams(context.Response.OutputStream));
}
}
else if (result is ISparqlDataset)
{
//Wrap in a Triple Store and then call self so the Triple Store writing branch of this if gets called instead
TripleStore store = new TripleStore(new DatasetGraphCollection((ISparqlDataset)result));
HandlerHelper.SendToClient(context, store, config);
}
else
{
throw new RdfOutputException("Unexpected Result Object of Type '" + result.GetType().ToString() + "' returned - unable to write Objects of this Type to the HTTP Response");
}
}
public void ProcessRequest(HttpContext context)
{
//Turn on Response Buffering
context.Response.Buffer = true;
//Prepare the Cache Directories
if (!Path.IsPathRooted(this._cacheDir))
{
this._cacheDir = context.Server.MapPath(this._cacheDir);
}
if (this._loader == null)
{
this._loader = new ExpansionLoader(this._cacheDir);
}
//Add our Custom Headers
try
{
context.Response.Headers.Add("X-dotNetRDF-Version", Assembly.GetAssembly(typeof(VDS.RDF.IGraph)).GetName().Version.ToString());
}
catch (PlatformNotSupportedException)
{
context.Response.AddHeader("X-dotNetRDF-Version", Assembly.GetAssembly(typeof(VDS.RDF.IGraph)).GetName().Version.ToString());
}
try
{
//Retrieve the desired URI and Profile URI from Querystring parameters
String uri = context.Request.QueryString["uri"];
String profile = context.Request.QueryString["profile"];
if (uri == null)
{
if (context.Request.Url.Query.Equals(String.Empty))
{
throw new ArgumentNullException("uri", "Required uri parameter used to designate the URI you wish to expand was not found. Your request must use a URI of the form " + context.Request.Url.ToString() + "?uri=" + Uri.EscapeDataString("http://example.org"));
}
else
{
throw new ArgumentNullException("uri", "Required uri parameter used to designate the URI you wish to expand was not found. Your request must use a URI of the form " + context.Request.Url.ToString().Replace(context.Request.Url.Query, String.Empty) + "?uri=" + Uri.EscapeDataString("http://example.org"));
}
}
//Note that the ExpansionLoader class automatically handles all the Caching for us
IInMemoryQueryableStore store;
String uriHash = new Uri(uri).GetSha256Hash();
if (profile == null)
{
//Use Default Profile
store = this._loader.Load(new Uri(uri));
}
else
{
//Use Custom Profile
store = this._loader.Load(new Uri(uri), new Uri(profile));
}
String ctype;
IStoreWriter writer = MimeTypesHelper.GetStoreWriter(context.Request.AcceptTypes, out ctype);
context.Response.ContentType = ctype;
writer.Save(store, new StreamParams(context.Response.OutputStream));
}
catch (ArgumentNullException argNull)
{
HandleErrors(context, "Missing Argument", argNull);
}
catch (RdfParseException parseEx)
{
HandleErrors(context, "RDF Parser Error", parseEx);
}
catch (RdfException rdfEx)
{
HandleErrors(context, "RDF Error", rdfEx);
}
catch (Exception ex)
{
HandleErrors(context, "Error", ex);
}
}
private bool SetOptions(String[] args)
{
if (args.Length == 0 || (args.Length == 1 && args[0].Equals("-help")))
{
this.ShowUsage();
return(false);
}
//Look through the arguments to see what we've been asked to do
foreach (String arg in args)
{
if (arg.StartsWith("-uri:"))
{
this._inputs.Add(arg);
}
else if (arg.StartsWith("-hs"))
{
if (arg.Contains(':'))
{
bool hs;
if (Boolean.TryParse(arg.Substring(arg.IndexOf(':') + 1), out hs))
{
this._options.Add(new HighSpeedOption(hs));
}
else
{
this._options.Add(new HighSpeedOption(true));
}
}
else
{
this._options.Add(new HighSpeedOption(true));
}
}
else if (arg.StartsWith("-pp"))
{
if (arg.Contains(':'))
{
bool pp;
if (Boolean.TryParse(arg.Substring(arg.IndexOf(':') + 1), out pp))
{
this._options.Add(new PrettyPrintingOption(pp));
}
else
{
this._options.Add(new PrettyPrintingOption(true));
}
}
else
{
this._options.Add(new PrettyPrintingOption(true));
}
}
else if (arg.StartsWith("-c"))
{
if (arg.Contains(':'))
{
int c;
if (Int32.TryParse(arg.Substring(arg.IndexOf(':') + 1), out c))
{
this._options.Add(new CompressionLevelOption(c));
}
else
{
this._options.Add(new CompressionLevelOption(WriterCompressionLevel.Default));
}
}
else
{
this._options.Add(new CompressionLevelOption(WriterCompressionLevel.Default));
}
}
else if (arg.StartsWith("-stylesheet:"))
{
String stylesheet = arg.Substring(arg.IndexOf(':') + 1);
this._options.Add(new StylesheetOption(stylesheet));
}
else if (arg.Equals("-merge"))
{
this._merge = true;
}
else if (arg.Equals("-overwrite"))
{
this._overwrite = true;
}
else if (arg.Equals("-dataset"))
{
this._dataset = true;
this._merge = true;
}
else if (arg.StartsWith("-out:") || arg.StartsWith("-output:"))
{
this._output = arg.Substring(arg.IndexOf(':') + 1);
//If the Writers have not been set then we'll set them now
if (this._writer == null && this._storeWriter == null)
{
String format;
try
{
format = MimeTypesHelper.GetMimeType(Path.GetExtension(this._output));
}
catch (RdfException)
{
Console.Error.WriteLine("rdfConvert: The File Extension '" + Path.GetExtension(this._output) + "' is not permissible since dotNetRDF cannot infer a MIME type from the extension");
return(false);
}
try
{
this._writer = MimeTypesHelper.GetWriter(format);
}
catch (RdfException)
{
//Supress this error
}
try
{
this._storeWriter = MimeTypesHelper.GetStoreWriter(format);
if (this._writer == null)
{
this._merge = true;
}
else if (this._writer is NTriplesWriter && !Path.GetExtension(this._output).Equals(".nt"))
{
this._writer = null;
this._merge = true;
}
}
catch (RdfException)
{
//Suppress this error
}
if (this._writer == null && this._storeWriter == null)
{
Console.Error.WriteLine("rdfConvert: The MIME Type '" + format + "' is not permissible since dotNetRDF does not support outputting in that format");
return(false);
}
}
}
else if (arg.StartsWith("-outformat:"))
{
String format = arg.Substring(arg.IndexOf(':') + 1);
if (!format.Contains("/"))
{
try
{
format = MimeTypesHelper.GetMimeType(format);
}
catch (RdfException)
{
Console.Error.WriteLine("rdfConvert: The File Extension '" + format + "' is not permissible since dotNetRDF cannot infer a MIME type from the extension");
return(false);
}
}
//Validate the MIME Type
if (!IsValidMimeType(format))
{
Console.Error.WriteLine("rdfConvert: The MIME Type '" + format + "' is not permissible since dotNetRDF does not support outputting in that format");
return(false);
}
try
{
this._writer = MimeTypesHelper.GetWriter(format);
this._outExt = MimeTypesHelper.GetFileExtension(this._writer);
}
catch (RdfException)
{
//Supress this error
}
try
{
this._storeWriter = MimeTypesHelper.GetStoreWriter(format);
if (this._writer == null)
{
//In the event that we can't get a valid Writer then individual graphs
//will be put into a Store and output as a Dataset
this._merge = true;
this._outExt = MimeTypesHelper.GetFileExtension(this._storeWriter);
}
else if (this._writer is NTriplesWriter && (!format.Equals("nt") || !format.Equals(".nt") || !format.Equals("text/plain")))
{
this._writer = null;
this._merge = true;
this._outExt = MimeTypesHelper.GetFileExtension(this._storeWriter);
}
}
catch (RdfException)
{
//Suppress this error
}
if (this._writer == null && this._storeWriter == null)
{
Console.Error.WriteLine("rdfConvert: The MIME Type '" + format + "' is not permissible since dotNetRDF does not support outputting in that format");
return(false);
}
}
else if (arg.StartsWith("-outext:"))
{
this._outExt = arg.Substring(arg.IndexOf(':') + 1);
if (!this._outExt.StartsWith("."))
{
this._outExt = "." + this._outExt;
}
}
else if (arg.Equals("-debug"))
{
this._debug = true;
}
else if (arg.Equals("-help"))
{
//Ignore help argument if other arguments are present
}
else if (arg.Equals("-nocache"))
{
Options.UriLoaderCaching = false;
}
else if (arg.Equals("-nobom"))
{
Options.UseBomForUtf8 = false;
}
else if (arg.Equals("-warnings"))
{
this._warnings = true;
UriLoader.Warning += this.ShowWarning;
UriLoader.StoreWarning += this.ShowWarning;
FileLoader.Warning += this.ShowWarning;
FileLoader.StoreWarning += this.ShowWarning;
}
else
{
//Anything else is treated as an input file
this._inputs.Add(arg);
}
}
//If there are no this._inputs then we'll abort
if (this._inputs.Count == 0)
{
Console.Error.WriteLine("rdfConvert: No Inputs were provided - please provide one/more files or URIs you wish to convert");
return(false);
}
//If there are no writers specified then we'll abort
if (this._writer == null && this._storeWriter == null)
{
Console.Error.WriteLine("rdfConvert: Aborting since no output options have been specified, use the -out:filename or -outformat: arguments to specify output format");
return(false);
}
if (!this._outExt.Equals(String.Empty))
{
if (!this._outExt.StartsWith("."))
{
this._outExt = "." + this._outExt;
}
}
else if (!this._output.Equals(String.Empty))
{
this._outExt = Path.GetExtension(this._output);
}
//Apply the Options to the Writers
foreach (IConversionOption option in this._options)
{
if (this._writer != null)
{
option.Apply(this._writer);
}
if (this._storeWriter != null)
{
option.Apply(this._storeWriter);
}
}
return(true);
}
