25QString QgsFieldCalculatorAlgorithm::name()
const
27 return QStringLiteral(
"fieldcalculator" );
30QString QgsFieldCalculatorAlgorithm::displayName()
const
32 return QObject::tr(
"Field calculator" );
35QStringList QgsFieldCalculatorAlgorithm::tags()
const
37 return QObject::tr(
"field,calculator,vector" ).split(
',' );
40QString QgsFieldCalculatorAlgorithm::group()
const
42 return QObject::tr(
"Vector table" );
45QString QgsFieldCalculatorAlgorithm::groupId()
const
47 return QStringLiteral(
"vectortable" );
50QString QgsFieldCalculatorAlgorithm::outputName()
const
52 return QObject::tr(
"Calculated" );
55QList<int> QgsFieldCalculatorAlgorithm::inputLayerTypes()
const
65void QgsFieldCalculatorAlgorithm::initParameters(
const QVariantMap &configuration )
67 Q_UNUSED( configuration )
69 QStringList fieldTypes;
71 fieldTypes.reserve( 11 );
73 for (
const auto &type :
74 std::vector < std::pair< QMetaType::Type, QMetaType::Type > >
76 {QMetaType::Type::Double, QMetaType::Type::UnknownType },
77 {QMetaType::Type::Int, QMetaType::Type::UnknownType },
78 {QMetaType::Type::QString, QMetaType::Type::UnknownType },
79 {QMetaType::Type::QDate, QMetaType::Type::UnknownType },
80 {QMetaType::Type::QTime, QMetaType::Type::UnknownType },
81 {QMetaType::Type::QDateTime, QMetaType::Type::UnknownType },
82 {QMetaType::Type::Bool, QMetaType::Type::UnknownType },
83 {QMetaType::Type::QByteArray, QMetaType::Type::UnknownType },
84 {QMetaType::Type::QStringList, QMetaType::Type::UnknownType },
85 {QMetaType::Type::QVariantList, QMetaType::Type::Int },
86 {QMetaType::Type::QVariantList, QMetaType::Type::Double }
93 std::unique_ptr< QgsProcessingParameterString > fieldName = std::make_unique< QgsProcessingParameterString > ( QStringLiteral(
"FIELD_NAME" ), QObject::tr(
"Field name" ), QVariant(),
false );
94 std::unique_ptr< QgsProcessingParameterEnum > fieldType = std::make_unique< QgsProcessingParameterEnum > ( QStringLiteral(
"FIELD_TYPE" ), QObject::tr(
"Result field type" ), fieldTypes,
false, 0 );
95 fieldType->setMetadata(
98 QStringLiteral(
"widget_wrapper" ),
101 QStringLiteral(
"icons" ), icons
107 std::unique_ptr< QgsProcessingParameterNumber > fieldLength = std::make_unique< QgsProcessingParameterNumber > ( QStringLiteral(
"FIELD_LENGTH" ), QObject::tr(
"Result field length" ),
Qgis::ProcessingNumberParameterType::Integer, QVariant( 0 ),
false, 0 );
108 std::unique_ptr< QgsProcessingParameterNumber > fieldPrecision = std::make_unique< QgsProcessingParameterNumber > ( QStringLiteral(
"FIELD_PRECISION" ), QObject::tr(
"Result field precision" ),
Qgis::ProcessingNumberParameterType::Integer, QVariant( 0 ),
false, 0 );
109 std::unique_ptr< QgsProcessingParameterExpression > expression = std::make_unique< QgsProcessingParameterExpression> ( QStringLiteral(
"FORMULA" ), QObject::tr(
"Formula" ), QVariant(), QStringLiteral(
"INPUT" ),
false );
111 expression->setMetadata( QVariantMap( {{
"inlineEditor",
true}} ) );
113 addParameter( fieldName.release() );
114 addParameter( fieldType.release() );
115 addParameter( fieldLength.release() );
116 addParameter( fieldPrecision.release() );
117 addParameter( expression.release() );
125QString QgsFieldCalculatorAlgorithm::shortHelpString()
const
127 return QObject::tr(
"This algorithm computes a new vector layer with the same features of the input layer, "
128 "but either overwriting an existing attribute or adding an additional attribute. The values of this field "
129 "are computed from each feature using an expression, based on the properties and attributes of the feature. "
130 "Note that if \"Field name\" is an existing field in the layer then all the rest of the field settings are ignored." );
133QgsFieldCalculatorAlgorithm *QgsFieldCalculatorAlgorithm::createInstance()
const
135 return new QgsFieldCalculatorAlgorithm();
141 std::unique_ptr< QgsProcessingFeatureSource > source( parameterAsSource( parameters, QStringLiteral(
"INPUT" ), context ) );
147 const int fieldTypeIdx = parameterAsInt( parameters, QStringLiteral(
"FIELD_TYPE" ), context );
148 const int fieldLength = parameterAsInt( parameters, QStringLiteral(
"FIELD_LENGTH" ), context );
149 const int fieldPrecision = parameterAsInt( parameters, QStringLiteral(
"FIELD_PRECISION" ), context );
150 const QString fieldName = parameterAsString( parameters, QStringLiteral(
"FIELD_NAME" ), context );
152 QMetaType::Type fieldType = QMetaType::Type::QString;
153 QMetaType::Type fieldSubType = QMetaType::Type::UnknownType;
154 switch ( fieldTypeIdx )
157 fieldType = QMetaType::Type::Double;
160 fieldType = QMetaType::Type::Int;
163 fieldType = QMetaType::Type::QString;
166 fieldType = QMetaType::Type::QDate;
169 fieldType = QMetaType::Type::QTime;
172 fieldType = QMetaType::Type::QDateTime;
175 fieldType = QMetaType::Type::Bool;
178 fieldType = QMetaType::Type::QByteArray;
181 fieldType = QMetaType::Type::QStringList;
182 fieldSubType = QMetaType::Type::QString;
185 fieldType = QMetaType::Type::QVariantList;
186 fieldSubType = QMetaType::Type::Int;
189 fieldType = QMetaType::Type::QVariantList;
190 fieldSubType = QMetaType::Type::Double;
194 if ( fieldName.isEmpty() )
207 mFields = source->fields();
209 const int fieldIdx = mFields.indexFromName( field.name() );
213 mFields.append( field );
217 feedback->
pushWarning( QObject::tr(
"Field name %1 already exists and will be replaced" ).arg( field.name() ) );
220 mFieldIdx = mFields.lookupField( field.name() );
223 const QString expressionString = parameterAsString( parameters, QStringLiteral(
"FORMULA" ), context );
224 mExpressionContext = createExpressionContext( parameters, context, source.get() );
229 mExpression.setGeomCalculator( &mDa );
231 mExpression.setAreaUnits( context.
areaUnit() );
233 if ( mExpression.hasParserError() )
235 .arg( expressionString, mExpression.parserErrorString() ) );
237 mExpression.prepare( &mExpressionContext );
245 const QStringList fieldNames = mFields.names();
246 for (
const QString &fieldName : fieldNames )
250 if ( attributeIndex >= 0 )
251 attributes[attributeIndex] = feature.
attribute( fieldName );
254 if ( mExpression.isValid() )
256 mExpressionContext.setFeature( feature );
257 mExpressionContext.lastScope()->setVariable( QStringLiteral(
"row_number" ), mRowNumber );
259 const QVariant value = mExpression.evaluate( &mExpressionContext );
261 if ( mExpression.hasEvalError() )
264 .arg( mExpression.expression(), mExpression.evalErrorString() ) );
267 attributes[mFieldIdx] = value;
271 attributes[mFieldIdx] = QVariant();
280bool QgsFieldCalculatorAlgorithm::supportInPlaceEdit(
const QgsMapLayer *layer )
const
@ Vector
Tables (i.e. vector layers with or without geometry). When used for a sink this indicates the sink ha...
@ SkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
QFlags< ProcessingFeatureSourceFlag > ProcessingFeatureSourceFlags
Flags which control how QgsProcessingFeatureSource fetches features.
Class for parsing and evaluation of expressions (formerly called "search strings").
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
int fieldNameIndex(const QString &fieldName) const
Utility method to get attribute index from name.
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
Q_INVOKABLE QVariant attribute(const QString &name) const
Lookup attribute value by attribute name.
Encapsulate a field in an attribute table or data source.
Container of fields for a vector layer.
static QIcon iconForFieldType(QMetaType::Type type, QMetaType::Type subType=QMetaType::Type::UnknownType, const QString &typeString=QString())
Returns an icon corresponding to a field type.
Base class for all map layer types.
Contains information about the context in which a processing algorithm is executed.
QgsCoordinateTransformContext transformContext() const
Returns the coordinate transform context.
Qgis::AreaUnit areaUnit() const
Returns the area unit to use for area calculations.
Qgis::DistanceUnit distanceUnit() const
Returns the distance unit to use for distance calculations.
QString ellipsoid() const
Returns the ellipsoid to use for distance and area calculations.
Custom exception class for processing related exceptions.
Base class for providing feedback from a processing algorithm.
virtual void pushWarning(const QString &warning)
Pushes a warning informational message from the algorithm.
static QString typeToDisplayString(QMetaType::Type type, QMetaType::Type subType=QMetaType::Type::UnknownType)
Returns a user-friendly translated string representing a QVariant type.
QList< QgsFeature > QgsFeatureList