QGIS API Documentation 3.27.0-Master (75dc696944)
qgsdataprovider.h
Go to the documentation of this file.
1/***************************************************************************
2 qgsdataprovider.h - DataProvider Interface class
3 --------------------------------------
4 Date : 09-Sep-2003
5 Copyright : (C) 2003 by Gary E.Sherman
6 email : sherman at mrcc.com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#ifndef QQGSDATAPROVIDER_H
17#define QQGSDATAPROVIDER_H
18
19#include "qgis_core.h"
20#include <QDateTime>
21#include <QObject>
22#include <QString>
23#include <QStringList>
24#include <QMutex>
25
26#include "qgsdatasourceuri.h"
28#include "qgslayermetadata.h"
29#include "qgserror.h"
30
31class QgsRectangle;
34
35
40class CORE_EXPORT QgsDataProvider : public QObject
41{
42
43#ifdef SIP_RUN
45 if ( qobject_cast<QgsVectorDataProvider *>( sipCpp ) )
46 {
47 sipType = sipType_QgsVectorDataProvider;
48 }
49 else if ( qobject_cast<QgsRasterDataProvider *>( sipCpp ) )
50 {
51 sipType = sipType_QgsRasterDataProvider;
52 }
53 else if ( qobject_cast<QgsMeshDataProvider *>( sipCpp ) )
54 {
55 sipType = sipType_QgsMeshDataProvider;
56 }
57 else if ( qobject_cast<QgsPointCloudDataProvider *>( sipCpp ) )
58 {
59 sipType = sipType_QgsPointCloudDataProvider;
60 }
61 else
62 {
63 sipType = 0;
64 }
66#endif
67 Q_OBJECT
68
69 public:
70
71 // TODO QGIS 4: (re)move DataCapability as this enum is really meant for data items rather than data providers
72
77 {
78 NoDataCapabilities = 0,
79 File = 1,
80 Dir = 1 << 1,
81 Database = 1 << 2,
82 Net = 1 << 3 // Internet source
83 };
84 Q_DECLARE_FLAGS( DataCapabilities, DataCapability )
85
86
94 {
96 CustomData = 3000
97 };
98
99
108 {
109
114
115 };
116
122 {
123 FlagTrustDataSource = 1 << 0,
124 SkipFeatureCount = 1 << 1,
125 FlagLoadDefaultStyle = 1 << 2,
126 SkipGetExtent = 1 << 3,
127 SkipFullScan = 1 << 4,
128 };
129 Q_DECLARE_FLAGS( ReadFlags, ReadFlag )
130
131
136 QgsDataProvider( const QString &uri = QString(),
138 QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() );
139
146
152 virtual void setDataSourceUri( const QString &uri )
153 {
154 mDataSourceURI = uri;
155 }
156
166 virtual QString dataSourceUri( bool expandAuthConfig = false ) const
167 {
168 if ( expandAuthConfig && mDataSourceURI.contains( QLatin1String( "authcfg" ) ) )
169 {
170 const QgsDataSourceUri uri( mDataSourceURI );
171 return uri.uri( expandAuthConfig );
172 }
173 else
174 {
175 return mDataSourceURI;
176 }
177 }
178
186 virtual QString dataComment() const { return QString(); };
187
188
194 void setUri( const QgsDataSourceUri &uri )
195 {
196 mDataSourceURI = uri.uri( true );
197 }
198
205 {
206 return QgsDataSourceUri( mDataSourceURI );
207 }
208
214 virtual Qgis::DataProviderFlags flags() const;
215
223 virtual QgsDataProviderTemporalCapabilities *temporalCapabilities();
224
232 virtual const QgsDataProviderTemporalCapabilities *temporalCapabilities() const SIP_SKIP;
233
238 virtual QgsRectangle extent() const = 0;
239
240
245 virtual bool isValid() const = 0;
246
250 virtual void updateExtents()
251 {
252 // NOP by default
253 }
254
255
262 virtual bool setSubsetString( const QString &subset, bool updateFeatureCount = true )
263 {
264 // NOP by default
265 Q_UNUSED( subset )
266 Q_UNUSED( updateFeatureCount )
267 return false;
268 }
269
270
274 virtual bool supportsSubsetString() const { return false; }
275
282 virtual QString subsetString() const
283 {
284 return QString();
285 }
286
287
296 virtual QStringList subLayers() const
297 {
298 return QStringList(); // Empty
299 }
300
308 virtual QStringList subLayerStyles() const
309 {
310 return QStringList(); // Empty
311 }
312
313
317 virtual uint subLayerCount() const
318 {
319 return 0;
320 }
321
322
328 virtual void setLayerOrder( const QStringList &layers )
329 {
330 //prevent unused var warnings
331 if ( layers.count() < 1 )
332 {
333 return;
334 }
335 // NOOP
336 }
337
338
342 virtual void setSubLayerVisibility( const QString &name, bool vis )
343 {
344 //prevent unused var warnings
345 if ( name.isEmpty() || !vis )
346 {
347 return;
348 }
349 // NOOP
350 }
351
352
368 virtual QString name() const = 0;
369
370
383 virtual QString description() const = 0;
384
385
396 virtual QString fileVectorFilters() const
397 {
398 return QString();
399 }
400
401
412 virtual QString fileRasterFilters() const
413 {
414 return QString();
415 }
416
417 // TODO QGIS 4 -> Make `reloadData()` non virtual. This should be implemented in `reloadProviderData()`.
418
426 virtual void reloadData();
427
429 virtual QDateTime timestamp() const { return mTimestamp; }
430
432 virtual QDateTime dataTimestamp() const { return QDateTime(); }
433
439 virtual QgsError error() const { return mError; }
440
445 virtual void invalidateConnections( const QString &connection ) { Q_UNUSED( connection ) }
446
469 virtual bool enterUpdateMode() { return true; }
470
488 virtual bool leaveUpdateMode() { return true; }
489
496 void setProviderProperty( ProviderProperty property, const QVariant &value );
497
504 void setProviderProperty( int property, const QVariant &value ); // SIP_SKIP
505
512 QVariant providerProperty( ProviderProperty property, const QVariant &defaultValue = QVariant() ) const;
513
520 QVariant providerProperty( int property, const QVariant &defaultValue ) const; // SIP_SKIP
521
532 virtual void setListening( bool isListening );
533
534#ifndef SIP_RUN
535
542 {
544 double lastRenderingTimeMs = -1;
545
547 double maxRenderingTimeMs = MAXIMUM_LAYER_PREVIEW_TIME_MS;
548 };
549#endif
550
563 virtual bool renderInPreview( const QgsDataProvider::PreviewContext &context ); // SIP_SKIP
564
573 virtual QgsLayerMetadata layerMetadata() const { return QgsLayerMetadata(); }
574
583 virtual bool writeLayerMetadata( const QgsLayerMetadata &metadata ) { Q_UNUSED( metadata ) return false; }
584
592 QgsCoordinateTransformContext transformContext() const SIP_SKIP;
593
604 virtual void setTransformContext( const QgsCoordinateTransformContext &transformContext ) SIP_SKIP;
605
612 static QString sublayerSeparator();
613
614 signals:
615
622 void fullExtentCalculated();
623
636 void dataChanged();
637
645 void notify( const QString &msg );
646
647
648 protected:
649
653 QDateTime mTimestamp;
654
656 QgsError mError;
657
659 void appendError( const QgsErrorMessage &message ) { mError.append( message ); }
660
662 void setError( const QgsError &error ) { mError = error;}
663
665 QgsDataProvider::ReadFlags mReadFlags = QgsDataProvider::ReadFlags();
666
667 private:
668
673 QString mDataSourceURI;
674
676
677 QMap< int, QVariant > mProviderProperties;
678
682 mutable QMutex mOptionsMutex;
683
688 virtual void reloadProviderData() {}
689};
690
691Q_DECLARE_OPERATORS_FOR_FLAGS( QgsDataProvider::ReadFlags )
692
693#endif
This class represents a coordinate reference system (CRS).
Contains information about the context in which a coordinate transform is executed.
Base class for handling properties relating to a data provider's temporal capabilities.
Abstract base class for spatial data provider implementations.
virtual void invalidateConnections(const QString &connection)
Invalidate connections corresponding to specified name.
virtual bool leaveUpdateMode()
Leave update mode.
void setUri(const QgsDataSourceUri &uri)
Set the data source specification.
virtual void setLayerOrder(const QStringList &layers)
Reorder the list of layer names to be rendered by this provider (in order from bottom to top)
ReadFlag
Flags which control dataprovider construction.
virtual QString name() const =0
Returns a provider name.
void setError(const QgsError &error)
Sets error message.
virtual QDateTime timestamp() const
Time stamp of data source in the moment when data/metadata were loaded by provider.
virtual QgsCoordinateReferenceSystem crs() const =0
Returns the coordinate system for the data source.
virtual QString dataComment() const
Returns a short comment for the data that this provider is providing access to (e....
ProviderProperty
Properties are used to pass custom configuration options into data providers.
@ EvaluateDefaultValues
Evaluate default values on provider side when calling QgsVectorDataProvider::defaultValue( int index ...
virtual QString subsetString() const
Returns the subset definition string (typically sql) currently in use by the layer and used by the pr...
virtual QgsLayerMetadata layerMetadata() const
Returns layer metadata collected from the provider's source.
virtual void setDataSourceUri(const QString &uri)
Set the data source specification.
virtual QString fileRasterFilters() const
Returns raster file filter string.
virtual QgsError error() const
Gets current status error.
DataCapability
Used in browser model to understand which items for which providers should be populated.
virtual QDateTime dataTimestamp() const
Current time stamp of data source.
virtual bool supportsSubsetString() const
Returns true if the provider supports setting of subset strings.
virtual QString dataSourceUri(bool expandAuthConfig=false) const
Gets the data source specification.
virtual QString description() const =0
Returns description.
QgsDataSourceUri uri() const
Gets the data source specification.
virtual QString fileVectorFilters() const
Returns vector file filter string.
virtual QStringList subLayerStyles() const
Sub-layer styles for each sub-layer handled by this provider, in order from bottom to top.
virtual bool setSubsetString(const QString &subset, bool updateFeatureCount=true)
Set the subset string used to create a subset of features in the layer.
virtual uint subLayerCount() const
Returns the number of layers for the current data source.
virtual QStringList subLayers() const
Sub-layers handled by this provider, in order from bottom to top.
virtual bool writeLayerMetadata(const QgsLayerMetadata &metadata)
Writes layer metadata to the underlying provider source.
virtual bool enterUpdateMode()
Enter update mode.
virtual void setSubLayerVisibility(const QString &name, bool vis)
Set the visibility of the given sublayer name.
Class for storing the component parts of a RDBMS data source URI (e.g.
QString uri(bool expandAuthConfig=true) const
Returns the complete URI as a string.
QgsErrorMessage represents single error message.
Definition: qgserror.h:33
QgsError is container for error messages (report).
Definition: qgserror.h:81
void append(const QString &message, const QString &tag)
Append new error message.
Definition: qgserror.cpp:39
A structured metadata store for a map layer.
A rectangle specified with double values.
Definition: qgsrectangle.h:42
#define SIP_CONVERT_TO_SUBCLASS_CODE(code)
Definition: qgis_sip.h:186
#define SIP_SKIP
Definition: qgis_sip.h:126
#define SIP_END
Definition: qgis_sip.h:203
Q_DECLARE_OPERATORS_FOR_FLAGS(QgsField::ConfigurationFlags) CORE_EXPORT QDataStream &operator<<(QDataStream &out
Writes the field to stream out. QGIS version compatibility is not guaranteed.
Stores settings related to the context in which a preview job runs.
Setting options for creating vector data providers.
QgsCoordinateTransformContext transformContext
Coordinate transform context.