22QString QgsAddUniqueValueIndexAlgorithm::name()
const
24 return QStringLiteral(
"adduniquevalueindexfield" );
27QString QgsAddUniqueValueIndexAlgorithm::displayName()
const
29 return QObject::tr(
"Add unique value index field" );
32QStringList QgsAddUniqueValueIndexAlgorithm::tags()
const
34 return QObject::tr(
"categorize,categories,category,reclassify,classes,create" ).split(
',' );
37QString QgsAddUniqueValueIndexAlgorithm::group()
const
39 return QObject::tr(
"Vector table" );
42QString QgsAddUniqueValueIndexAlgorithm::groupId()
const
44 return QStringLiteral(
"vectortable" );
47void QgsAddUniqueValueIndexAlgorithm::initAlgorithm(
const QVariantMap & )
51 addParameter(
new QgsProcessingParameterString( QStringLiteral(
"FIELD_NAME" ), QObject::tr(
"Output field name" ), QStringLiteral(
"NUM_FIELD" ) ) );
54 classedOutput->setCreateByDefault(
true );
55 addParameter( classedOutput.release() );
57 auto summaryOutput = std::make_unique<QgsProcessingParameterFeatureSink>( QStringLiteral(
"SUMMARY_OUTPUT" ), QObject::tr(
"Class summary" ),
Qgis::ProcessingSourceType::Vector, QVariant(),
true );
58 summaryOutput->setCreateByDefault(
false );
59 addParameter( summaryOutput.release() );
62QString QgsAddUniqueValueIndexAlgorithm::shortHelpString()
const
64 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 "
65 "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"
66 "The new attribute is not added to the input layer but a new layer is generated instead.\n\n"
67 "Optionally, a separate table can be output which contains a summary of the class field values mapped to the new unique numeric value." );
70QString QgsAddUniqueValueIndexAlgorithm::shortDescription()
const
72 return QObject::tr(
"Adds a numeric field and assigns the same index to features of the same attribute value." );
75QgsAddUniqueValueIndexAlgorithm *QgsAddUniqueValueIndexAlgorithm::createInstance()
const
77 return new QgsAddUniqueValueIndexAlgorithm();
82 std::unique_ptr<QgsProcessingFeatureSource> source( parameterAsSource( parameters, QStringLiteral(
"INPUT" ), context ) );
86 const QString newFieldName = parameterAsString( parameters, QStringLiteral(
"FIELD_NAME" ), context );
91 throw QgsProcessingException( QObject::tr(
"A field with the same name (%1) already exists" ).arg( newFieldName ) );
98 std::unique_ptr<QgsFeatureSink> sink( parameterAsSink( parameters, QStringLiteral(
"OUTPUT" ), context, dest, fields, source->wkbType(), source->sourceCrs() ) );
100 const QString sourceFieldName = parameterAsString( parameters, QStringLiteral(
"FIELD" ), context );
101 const int fieldIndex = source->fields().lookupField( sourceFieldName );
102 if ( fieldIndex < 0 )
107 summaryFields.
append( newField );
108 summaryFields.
append( source->fields().at( fieldIndex ) );
109 std::unique_ptr<QgsFeatureSink> summarySink( parameterAsSink( parameters, QStringLiteral(
"SUMMARY_OUTPUT" ), context, summaryDest, summaryFields,
Qgis::WkbType::NoGeometry ) );
111 QHash<QVariant, int> classes;
115 const long count = source->featureCount();
116 const double step = count > 0 ? 100.0 / count : 1;
127 const QVariant clazz = attributes.at( fieldIndex );
129 int thisValue = classes.value( clazz, -1 );
130 if ( thisValue == -1 )
132 thisValue = classes.count();
133 classes.insert( clazz, thisValue );
138 attributes.append( thisValue );
151 QMap<int, QVariant> sorted;
152 for (
auto classIt = classes.constBegin(); classIt != classes.constEnd(); ++classIt )
154 sorted.insert( classIt.value(), classIt.key() );
157 for (
auto sortedIt = sorted.constBegin(); sortedIt != sorted.constEnd(); ++sortedIt )
162 throw QgsProcessingException( writeFeatureError( summarySink.get(), parameters, QStringLiteral(
"SUMMARY_OUTPUT" ) ) );
170 results.insert( QStringLiteral(
"OUTPUT" ), dest );
174 summarySink->finalize();
175 results.insert( QStringLiteral(
"SUMMARY_OUTPUT" ), summaryDest );
@ Vector
Tables (i.e. vector layers with or without geometry). When used for a sink this indicates the sink ha...
@ VectorAnyGeometry
Any vector layer with geometry.
@ SkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
Fetch next feature and stores in f, returns true on success.
Wraps a request for features to a vector layer (or directly its vector data provider).
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
bool isCanceled() const
Tells whether the operation has been canceled already.
void setProgress(double progress)
Sets the current progress for the feedback object.
Encapsulate a field in an attribute table or data source.
Container of fields for a vector layer.
bool append(const QgsField &field, Qgis::FieldOrigin origin=Qgis::FieldOrigin::Provider, int originIndex=-1)
Appends a field.
Q_INVOKABLE int lookupField(const QString &fieldName) const
Looks up field's index from the field name.
Contains information about the context in which a processing algorithm is executed.
Custom exception class for processing related exceptions.
Base class for providing feedback from a processing algorithm.
An input feature source (such as vector layers) parameter for processing algorithms.
A vector layer or feature source field parameter for processing algorithms.
A string parameter for processing algorithms.