QGIS API Documentation  3.21.0-Master (5b68dc587e)
qgsprocessingprovider.cpp
Go to the documentation of this file.
1 /***************************************************************************
2  qgsprocessingprovider.cpp
3  --------------------------
4  begin : December 2016
5  copyright : (C) 2016 by Nyall Dawson
6  email : nyall dot dawson at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #include "qgsprocessingprovider.h"
19 #include "qgsapplication.h"
20 #include "qgsvectorfilewriter.h"
21 #include "qgsrasterfilewriter.h"
22 #include "qgssettings.h"
23 
25  : QObject( parent )
26 {}
27 
28 
30 {
31  qDeleteAll( mAlgorithms );
32 }
33 
35 {
36  return QgsApplication::getThemeIcon( "/processingAlgorithm.svg" );
37 }
38 
40 {
41  return QgsApplication::iconPath( QStringLiteral( "processingAlgorithm.svg" ) );
42 }
43 
44 QgsProcessingProvider::Flags QgsProcessingProvider::flags() const
45 {
46  return QgsProcessingProvider::Flags();
47 }
48 
50 {
51  return QString();
52 }
53 
55 {
56  return name();
57 }
58 
60 {
61  return QString();
62 }
63 
65 {
67 }
68 
70 {
71  qDeleteAll( mAlgorithms );
72  mAlgorithms.clear();
73  if ( isActive() )
74  {
76  emit algorithmsLoaded();
77  }
78 }
79 
80 QList<const QgsProcessingAlgorithm *> QgsProcessingProvider::algorithms() const
81 {
82  return mAlgorithms.values();
83 }
84 
85 const QgsProcessingAlgorithm *QgsProcessingProvider::algorithm( const QString &name ) const
86 {
87  return mAlgorithms.value( name );
88 }
89 
91 {
92  if ( !algorithm )
93  return false;
94 
95  if ( mAlgorithms.contains( algorithm->name() ) )
96  {
97  QgsMessageLog::logMessage( tr( "Duplicate algorithm name %1 for provider %2" ).arg( algorithm->name(), id() ), QObject::tr( "Processing" ) );
98  return false;
99  }
100 
101  // init the algorithm - this allows direct querying of the algorithm's parameters
102  // and outputs from the provider's copy
103  algorithm->initAlgorithm( QVariantMap() );
104 
105  algorithm->setProvider( this );
106  mAlgorithms.insert( algorithm->name(), algorithm );
107  return true;
108 }
109 
111 {
113 }
114 
116 {
118 }
119 
120 bool QgsProcessingProvider::isSupportedOutputValue( const QVariant &outputValue, const QgsProcessingDestinationParameter *parameter, QgsProcessingContext &context, QString &error ) const
121 {
122  error.clear();
123  QString outputPath = QgsProcessingParameters::parameterAsOutputLayer( parameter, outputValue, context ).trimmed();
124 
125  if ( outputPath.isEmpty() )
126  {
128  {
129  return true;
130  }
131  else
132  {
133  error = tr( "Missing parameter value %1" ).arg( parameter->description() );
134  return false;
135  }
136  }
137 
140  {
141  if ( outputPath.startsWith( QLatin1String( "memory:" ) ) )
142  {
144  {
145  error = tr( "This algorithm only supports disk-based outputs" );
146  return false;
147  }
148  return true;
149  }
150 
151  QString providerKey;
152  QString uri;
153  QString layerName;
154  QMap<QString, QVariant> options;
155  bool useWriter = false;
156  QString format;
157  QString extension;
158  QgsProcessingUtils::parseDestinationString( outputPath, providerKey, uri, layerName, format, options, useWriter, extension );
159 
160  if ( providerKey != QLatin1String( "ogr" ) )
161  {
163  {
164  error = tr( "This algorithm only supports disk-based outputs" );
165  return false;
166  }
167  return true;
168  }
169 
170  if ( !supportedOutputVectorLayerExtensions().contains( extension, Qt::CaseInsensitive ) )
171  {
172  error = tr( "“.%1” files are not supported as outputs for this algorithm" ).arg( extension );
173  return false;
174  }
175  return true;
176  }
177  else if ( parameter->type() == QgsProcessingParameterRasterDestination::typeName() )
178  {
179  const QFileInfo fi( outputPath );
180  const QString extension = fi.completeSuffix();
181  if ( !supportedOutputRasterLayerExtensions().contains( extension, Qt::CaseInsensitive ) )
182  {
183  error = tr( "“.%1” files are not supported as outputs for this algorithm" ).arg( extension );
184  return false;
185  }
186  return true;
187  }
188  else
189  {
190  return true;
191  }
192 }
193 
194 QString QgsProcessingProvider::defaultVectorFileExtension( bool hasGeometry ) const
195 {
196  const QString userDefault = QgsProcessingUtils::defaultVectorExtension();
197 
198  const QStringList supportedExtensions = supportedOutputVectorLayerExtensions();
199  if ( supportedExtensions.contains( userDefault, Qt::CaseInsensitive ) )
200  {
201  // user set default is supported by provider, use that
202  return userDefault;
203  }
204  else if ( !supportedExtensions.empty() )
205  {
206  return supportedExtensions.at( 0 );
207  }
208  else
209  {
210  // who knows? provider says it has no file support at all...
211  // let's say shp. even MapInfo supports shapefiles.
212  return hasGeometry ? QStringLiteral( "shp" ) : QStringLiteral( "dbf" );
213  }
214 }
215 
217 {
218  const QString userDefault = QgsProcessingUtils::defaultRasterExtension();
219 
220  const QStringList supportedExtensions = supportedOutputRasterLayerExtensions();
221  if ( supportedExtensions.contains( userDefault, Qt::CaseInsensitive ) )
222  {
223  // user set default is supported by provider, use that
224  return userDefault;
225  }
226  else if ( !supportedExtensions.empty() )
227  {
228  return supportedExtensions.at( 0 );
229  }
230  else
231  {
232  // who knows? provider says it has no file support at all...
233  return QStringLiteral( "tif" );
234  }
235 }
236 
238 {
239  return true;
240 }
static QIcon getThemeIcon(const QString &name, const QColor &fillColor=QColor(), const QColor &strokeColor=QColor())
Helper to get a theme icon.
static QString iconPath(const QString &iconFile)
Returns path to the desired icon file.
static void logMessage(const QString &message, const QString &tag=QString(), Qgis::MessageLevel level=Qgis::MessageLevel::Warning, bool notifyUser=true)
Adds a message to the log instance (and creates it if necessary).
Abstract base class for processing algorithms.
void setProvider(QgsProcessingProvider *provider)
Associates this algorithm with its provider.
virtual void initAlgorithm(const QVariantMap &configuration=QVariantMap())=0
Initializes the algorithm using the specified configuration.
virtual QString name() const =0
Returns the algorithm name, used for identifying the algorithm.
Contains information about the context in which a processing algorithm is executed.
Base class for all parameter definitions which represent file or layer destinations,...
QString description() const
Returns the description for the parameter.
virtual QString type() const =0
Unique parameter type name.
Flags flags() const
Returns any flags associated with the parameter.
static QString typeName()
Returns the type name for the parameter class.
static QString typeName()
Returns the type name for the parameter class.
static QString typeName()
Returns the type name for the parameter class.
static QString parameterAsOutputLayer(const QgsProcessingParameterDefinition *definition, const QVariantMap &parameters, QgsProcessingContext &context)
Evaluates the parameter with matching definition to a output layer destination.
virtual QIcon icon() const
Returns an icon for the provider.
virtual QString defaultVectorFileExtension(bool hasGeometry=true) const
Returns the default file extension to use for vector outputs created by the provider.
virtual QString helpId() const
Returns the provider help id string, used for creating QgsHelp urls for algorithms belong to this pro...
virtual bool isSupportedOutputValue(const QVariant &outputValue, const QgsProcessingDestinationParameter *parameter, QgsProcessingContext &context, QString &error) const
Returns true if the specified outputValue is of a supported file format for the given destination par...
virtual QStringList supportedOutputTableExtensions() const
Returns a list of the table (geometry-less vector layers) file extensions supported by this provider.
const QgsProcessingAlgorithm * algorithm(const QString &name) const
Returns the matching algorithm by name, or nullptr if no matching algorithm is contained by this prov...
virtual QString versionInfo() const
Returns a version information string for the provider, or an empty string if this is not applicable (...
virtual QStringList supportedOutputVectorLayerExtensions() const
Returns a list of the vector format file extensions supported by this provider.
virtual QString name() const =0
Returns the provider name, which is used to describe the provider within the GUI.
virtual QStringList supportedOutputRasterLayerExtensions() const
Returns a list of the raster format file extensions supported by this provider.
QgsProcessingProvider(QObject *parent=nullptr)
Constructor for QgsProcessingProvider.
virtual bool isActive() const
Returns true if the provider is active and able to run algorithms.
virtual QString defaultRasterFileExtension() const
Returns the default file extension to use for raster outputs created by the provider.
void algorithmsLoaded()
Emitted when the provider has loaded (or refreshed) its list of available algorithms.
virtual QString svgIconPath() const
Returns a path to an SVG version of the provider's icon.
virtual void loadAlgorithms()=0
Loads all algorithms belonging to this provider.
void refreshAlgorithms()
Refreshes the algorithms available from the provider, causing it to re-populate with all associated a...
virtual QString longName() const
Returns the longer version of the provider name, which can include extra details such as version numb...
virtual bool supportsNonFileBasedOutput() const
Returns true if the provider supports non-file based outputs (such as memory layers or direct databas...
virtual Flags flags() const
Returns the flags indicating how and when the provider operates and should be exposed to users.
bool addAlgorithm(QgsProcessingAlgorithm *algorithm)
Adds an algorithm to the provider.
QList< const QgsProcessingAlgorithm * > algorithms() const
Returns a list of algorithms supplied by this provider.
static QString defaultVectorExtension()
Returns the default vector extension to use, in the absence of all other constraints (e....
static QString defaultRasterExtension()
Returns the default raster extension to use, in the absence of all other constraints (e....
static QStringList supportedFormatExtensions(RasterFormatOptions options=SortRecommended)
Returns a list of file extensions for supported formats.
static QStringList supportedFormatExtensions(VectorFormatOptions options=SortRecommended)
Returns a list of file extensions for supported formats, e.g "shp", "gpkg".
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into allowing algorithms to be written in pure substantial changes are required in order to port existing x Processing algorithms for QGIS x The most significant changes are outlined not GeoAlgorithm For algorithms which operate on features one by consider subclassing the QgsProcessingFeatureBasedAlgorithm class This class allows much of the boilerplate code for looping over features from a vector layer to be bypassed and instead requires implementation of a processFeature method Ensure that your algorithm(or algorithm 's parent class) implements the new pure virtual createInstance(self) call
#define SIP_TRANSFERTHIS
Definition: qgis_sip.h:53