22 QString QgsAddUniqueValueIndexAlgorithm::name()
const 24 return QStringLiteral(
"adduniquevalueindexfield" );
27 QString QgsAddUniqueValueIndexAlgorithm::displayName()
const 29 return QObject::tr(
"Add unique value index field" );
32 QStringList QgsAddUniqueValueIndexAlgorithm::tags()
const 34 return QObject::tr(
"categorize,categories,category,reclassify,classes,create" ).split(
',' );
37 QString QgsAddUniqueValueIndexAlgorithm::group()
const 39 return QObject::tr(
"Vector table" );
42 QString QgsAddUniqueValueIndexAlgorithm::groupId()
const 44 return QStringLiteral(
"vectortable" );
47 void QgsAddUniqueValueIndexAlgorithm::initAlgorithm(
const QVariantMap & )
54 QObject::tr(
"Output field name" ), QStringLiteral(
"NUM_FIELD" ) ) );
56 std::unique_ptr< QgsProcessingParameterFeatureSink > classedOutput = qgis::make_unique< QgsProcessingParameterFeatureSink >( QStringLiteral(
"OUTPUT" ), QObject::tr(
"Layer with index field" ),
QgsProcessing::TypeVectorAnyGeometry, QVariant(), true );
57 classedOutput->setCreateByDefault(
true );
58 addParameter( classedOutput.release() );
60 std::unique_ptr< QgsProcessingParameterFeatureSink > summaryOutput = qgis::make_unique< QgsProcessingParameterFeatureSink >( QStringLiteral(
"SUMMARY_OUTPUT" ), QObject::tr(
"Class summary" ),
62 summaryOutput->setCreateByDefault(
false );
63 addParameter( summaryOutput.release() );
66 QString QgsAddUniqueValueIndexAlgorithm::shortHelpString()
const 68 return QObject::tr(
"This algorithm takes a vector layer and an attribute and adds a new numeric field. Values in this field correspond to values in the specified attribute, so features with the same " 69 "value for the attribute will have the same value in the new numeric field. This creates a numeric equivalent of the specified attribute, which defines the same classes.\n\n" 70 "The new attribute is not added to the input layer but a new layer is generated instead.\n\n" 71 "Optionally, a separate table can be output which contains a summary of the class field values mapped to the new unique numeric value." );
74 QgsAddUniqueValueIndexAlgorithm *QgsAddUniqueValueIndexAlgorithm::createInstance()
const 76 return new QgsAddUniqueValueIndexAlgorithm();
81 std::unique_ptr< QgsProcessingFeatureSource > source( parameterAsSource( parameters, QStringLiteral(
"INPUT" ), context ) );
85 QString newFieldName = parameterAsString( parameters, QStringLiteral(
"FIELD_NAME" ), context );
91 std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral(
"OUTPUT" ), context, dest, fields, source->wkbType(), source->sourceCrs() ) );
93 QString sourceFieldName = parameterAsString( parameters, QStringLiteral(
"FIELD" ), context );
94 int fieldIndex = source->fields().lookupField( sourceFieldName );
100 summaryFields.
append( newField );
101 summaryFields.
append( source->fields().at( fieldIndex ) );
102 std::unique_ptr< QgsFeatureSink > summarySink( parameterAsSink( parameters, QStringLiteral(
"SUMMARY_OUTPUT" ), context, summaryDest, summaryFields,
QgsWkbTypes::NoGeometry ) );
104 QHash< QVariant, int > classes;
108 long count = source->featureCount();
109 double step = count > 0 ? 100.0 / count : 1;
120 QVariant clazz = attributes.at( fieldIndex );
122 int thisValue = classes.value( clazz, -1 );
123 if ( thisValue == -1 )
125 thisValue = classes.count();
126 classes.insert( clazz, thisValue );
131 attributes.append( thisValue );
143 QMap< int, QVariant > sorted;
144 for (
auto classIt = classes.constBegin(); classIt != classes.constEnd(); ++classIt )
146 sorted.insert( classIt.value(), classIt.key() );
149 for (
auto sortedIt = sorted.constBegin(); sortedIt != sorted.constEnd(); ++sortedIt )
159 results.insert( QStringLiteral(
"OUTPUT" ), dest );
161 results.insert( QStringLiteral(
"SUMMARY_OUTPUT" ), summaryDest );
Wrapper for iterator of features from vector data provider or vector layer.
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
Base class for providing feedback from a processing algorithm.
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
A vector layer or feature source field parameter for processing algorithms.
void setProgress(double progress)
Sets the current progress for the feedback object.
Container of fields for a vector layer.
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
This class wraps a request for features to a vector layer (or directly its vector data provider)...
Custom exception class for processing related exceptions.
bool append(const QgsField &field, FieldOrigin origin=OriginProvider, int originIndex=-1)
Appends a field. The field must have unique name, otherwise it is rejected (returns false) ...
Encapsulate a field in an attribute table or data source.
bool isCanceled() const
Tells whether the operation has been canceled already.
An input feature source (such as vector layers) parameter for processing algorithms.
Tables (i.e. vector layers with or without geometry). When used for a sink this indicates the sink ha...
bool nextFeature(QgsFeature &f)
Contains information about the context in which a processing algorithm is executed.
A string parameter for processing algorithms.
Any vector layer with geometry.