rdf/base/nsIRDFCompositeDataSource.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsIRDFDataSource.idl"
   7
   8 interface nsISimpleEnumerator;
   9
  10 /**
  11  * An nsIRDFCompositeDataSource composes individual data sources, providing
  12  * the illusion of a single, coherent RDF graph.
  13  */
  14 [scriptable, uuid(96343820-307C-11D2-BC15-00805F912FE7)]
  15 interface nsIRDFCompositeDataSource : nsIRDFDataSource {
  16
  17     /**
  18      *
  19      * Set this value to <code>true</code> if the composite datasource
  20      * may contains at least one datasource that has <em>negative</em>
  21      * assertions. (This is the default.)
  22      *
  23      * Set this value to <code>false</code> if none of the datasources
  24      * being composed contains a negative assertion. This allows the
  25      * composite datasource to perform some query optimizations.
  26      *
  27      * By default, this value is <code>true</true>.
  28      */
  29     attribute boolean   allowNegativeAssertions;
  30
  31     /**
  32      * Set to <code>true</code> if the composite datasource should
  33      * take care to coalesce duplicate arcs when returning values from
  34      * queries. (This is the default.)
  35      *
  36      * Set to <code>false</code> if the composite datasource shouldn't
  37      * bother to check for duplicates. This allows the composite
  38      * datasource to more efficiently answer queries.
  39      *
  40      * By default, this value is <code>true</code>.
  41      */
  42     attribute boolean   coalesceDuplicateArcs;
  43
  44     /**
  45      * Add a datasource the the composite data source.
  46      * @param aDataSource the datasource to add to composite
  47      */
  48     void AddDataSource(in nsIRDFDataSource aDataSource);
  49
  50     /**
  51      * Remove a datasource from the composite data source.
  52      * @param aDataSource the datasource to remove from the composite
  53      */
  54     void RemoveDataSource(in nsIRDFDataSource aDataSource);
  55
  56     /**
  57      * Retrieve the datasources in the composite data source.
  58      * @return an nsISimpleEnumerator that will enumerate each
  59      * of the datasources in the composite
  60      */
  61     nsISimpleEnumerator GetDataSources();
  62 };
  63
  64 %{C++
  65 extern nsresult
  66 NS_NewRDFCompositeDataSource(nsIRDFCompositeDataSource** result);
  67 %}
  68