runtime/nepomuk/services/ontologyloader/graphretriever.h

   1 /*  This file is part of the KDE semantic clipboard
   2     Copyright (C) 2008 Tobias Wolf <twolf@access.unizh.ch>
   3     Copyright (C) 2008 Sebastian Trueg <trueg@kde.org>
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Library General Public
   7     License as published by the Free Software Foundation; either
   8     version 2 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Library General Public License for more details.
  14
  15     You should have received a copy of the GNU Library General Public License
  16     along with this library; see the file COPYING.LIB.  If not, write to
  17     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18     Boston, MA 02110-1301, USA.
  19 */
  20
  21 #ifndef _NEPOMUK_GRAPHRETRIEVER_H_
  22 #define _NEPOMUK_GRAPHRETRIEVER_H_
  23
  24 #include <KJob>
  25
  26 class QString;
  27 class QUrl;
  28
  29 namespace Soprano {
  30     class Model;
  31     class StatementIterator;
  32 }
  33 namespace KIO {
  34     class Job;
  35 }
  36
  37 namespace Nepomuk
  38 {
  39
  40     /**
  41      * \class GraphRetriever graphretriever.h <nepomuk/graphretriever.h>
  42      *
  43      * \brief Utility class for retrieving RDF graphs from Web locations.
  44      *
  45      * GraphRetriever allows retrieval of multiple RDF graph fragments from
  46      * the Web using HTTP GET. Target HTTP servers should support the RDF+XML
  47      * request MIME type for this to work.
  48      *
  49      * Clients can queue multiple get requests and must follow the last get
  50      * request with a call to either model() or serialization().
  51      *
  52      * \author Tobias Wolf <twolf@access.unizh.ch>
  53      */
  54     class GraphRetriever : public KJob
  55     {
  56         Q_OBJECT
  57
  58     public:
  59         /**
  60          * Custom and default constructor.
  61          *
  62          * @param parent The parent QObject.
  63          */
  64         GraphRetriever( QObject* parent = 0 );
  65
  66         /**
  67          * Default destructor.
  68          */
  69         ~GraphRetriever();
  70
  71         static GraphRetriever* retrieve( const QUrl& uri );
  72
  73         void setUrl( const QUrl& url );
  74
  75         QUrl url() const;
  76
  77         /**
  78          * Adds a get request for the given URL.
  79          *
  80          * @param url An URL specifying the location of a graph fragment to get.
  81          * @return True if the get request was accepted, false otherwise.
  82          */
  83         void start();
  84
  85         /**
  86          * Returns a new Soprano model constructed from the retrieved graph fragments. The
  87          * client takes over ownership of the returned model.
  88          *
  89          * @return A new Soprano model constructed from the merged fragments.
  90          */
  91         Soprano::Model* model() const;
  92
  93         Soprano::StatementIterator statements() const;
  94
  95     private Q_SLOTS:
  96         /**
  97          * @internal
  98          */
  99         void httpRequestFinished( KJob* );
 100
 101     private:
 102         class Private;
 103         Private* const d;
 104     };
 105
 106 }
 107
 108 #endif