27QgsExpressionUtils::TVL QgsExpressionUtils::AND[3][3] =
30 { False, False, False },
34QgsExpressionUtils::TVL QgsExpressionUtils::OR[3][3] =
41QgsExpressionUtils::TVL QgsExpressionUtils::NOT[3] = { True, False,
Unknown };
44QColor QgsExpressionUtils::getColorValue(
const QVariant &value,
QgsExpression *parent,
bool &isQColor )
46 isQColor = value.userType() == QMetaType::Type::QColor;
47 QColor color = isQColor ? value.value<QColor>() :
QgsSymbolLayerUtils::decodeColor( value.toString() );
48 if ( ! color.isValid() )
51 : QObject::tr(
"Cannot convert '%1' to color" ).arg( value.toString() ) );
59 if ( value.userType() == qMetaTypeId<QgsGradientColorRamp>() )
64 parent->
setEvalErrorString( QObject::tr(
"Cannot convert '%1' to gradient ramp" ).arg( value.toString() ) );
71 return getMapLayerPrivate( value, context, parent );
80#ifdef __clang_analyzer__
90 qWarning(
"Raw map layer pointer stored in expression evaluation, switch to QgsWeakMapLayerPointer instead" );
97 const QString identifier = value.toString();
102 const QList< QgsMapLayerStore * > stores = context->
layerStores();
106 QPointer< QgsMapLayerStore > storePointer( store );
107 auto findLayerInStoreFunction = [ storePointer, &ml, identifier ]
112 ml = store->mapLayer( identifier );
118 ml = store->mapLayersByName( identifier ).value( 0 );
124 if ( QThread::currentThread() == store->thread() )
125 findLayerInStoreFunction();
127 QMetaObject::invokeMethod( store, findLayerInStoreFunction, Qt::BlockingQueuedConnection );
134 auto getMapLayerFromProjectInstance = [ &ml, identifier ]
139 ml = project->
mapLayer( identifier );
147 if ( QThread::currentThread() == qApp->thread() )
148 getMapLayerFromProjectInstance();
150 QMetaObject::invokeMethod( qApp, getMapLayerFromProjectInstance, Qt::BlockingQueuedConnection );
161#ifndef __clang_analyzer__
171 qWarning(
"Raw map layer pointer stored in expression evaluation, switch to QgsWeakMapLayerPointer instead" );
177 QPointer< QgsMapLayer > layerPointer( ml );
178 auto runFunction = [ layerPointer, &function, &foundLayer ]
190 if ( QThread::currentThread() == ml->thread() )
193 QMetaObject::invokeMethod( ml, runFunction, Qt::BlockingQueuedConnection );
201 auto runFunction = [ value, context, expression, &function, &foundLayer ]
203 if (
QgsMapLayer *layer = getMapLayerPrivate( value, context, expression ) )
226 const QString identifier = value.toString();
229 const QList< QgsMapLayerStore * > stores = context->layerStores();
233 QPointer< QgsMapLayerStore > storePointer( store );
234 auto findLayerInStoreFunction = [ storePointer, identifier, function, &foundLayer ]
240 ml = store->mapLayer( identifier );
244 ml = store->mapLayersByName( identifier ).value( 0 );
257 if ( QThread::currentThread() == store->thread() )
258 findLayerInStoreFunction();
260 QMetaObject::invokeMethod( store, findLayerInStoreFunction, Qt::BlockingQueuedConnection );
267 auto getMapLayerFromProjectInstance = [ value, identifier, &function, &foundLayer ]
288 getMapLayerFromProjectInstance();
290 QMetaObject::invokeMethod(
QgsProject::instance(), getMapLayerFromProjectInstance, Qt::BlockingQueuedConnection );
295QVariant QgsExpressionUtils::runMapLayerFunctionThreadSafe(
const QVariant &value,
const QgsExpressionContext *context,
QgsExpression *expression,
const std::function<QVariant(
QgsMapLayer * )> &function,
bool &foundLayer )
300 executeLambdaForMapLayer( value, context, expression, [&res, function](
QgsMapLayer * layer )
303 res = function( layer );
309std::unique_ptr<QgsVectorLayerFeatureSource> QgsExpressionUtils::getFeatureSource(
const QVariant &value,
const QgsExpressionContext *context,
QgsExpression *e,
bool &foundLayer )
311 std::unique_ptr<QgsVectorLayerFeatureSource> featureSource;
313 executeLambdaForMapLayer( value, context, e, [&featureSource](
QgsMapLayer * layer )
315 if (
QgsVectorLayer *vl = qobject_cast< QgsVectorLayer *>( layer ) )
321 return featureSource;
326 return qobject_cast<QgsVectorLayer *>( getMapLayerPrivate( value, context, e ) );
334 if (
QgsMapLayer *layer = getMapLayer( value, context, parent ) )
337 res = parts.value( QStringLiteral(
"path" ) ).toString();
342 res = value.toString();
366 for (
int i = 0; i < fields.
count(); i++ )
378 *foundFeatures = hasFeature;
382 const QVariant value = exp.
evaluate( &context );
385 return std::make_tuple(
static_cast<QMetaType::Type
>( value.userType() ), value.userType() );
390 return std::make_tuple(
static_cast<QMetaType::Type
>( value.userType() ), value.userType() );
@ NoGeometry
Geometry is not required. It may still be returned if e.g. required for a filter condition.
@ NoFlags
No flags are set.
@ Expression
Field is calculated from an expression.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
QList< QgsMapLayerStore * > layerStores() const
Returns the list of layer stores associated with the context.
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
static std::tuple< QMetaType::Type, int > determineResultType(const QString &expression, const QgsVectorLayer *layer, QgsFeatureRequest request=QgsFeatureRequest(), QgsExpressionContext context=QgsExpressionContext(), bool *foundFeatures=nullptr)
Returns a value type and user type for a given expression.
Class for parsing and evaluation of expressions (formerly called "search strings").
void setEvalErrorString(const QString &str)
Sets evaluation error (used internally by evaluation functions)
bool needsGeometry() const
Returns true if the expression uses feature geometry for some computation.
QVariant evaluate()
Evaluate the feature and return the result.
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.
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsFeatureRequest & setFlags(Qgis::FeatureRequestFlags flags)
Sets flags that affect how features will be fetched.
QgsFeatureRequest & setLimit(long long limit)
Set the maximum number of features to request.
QgsFeatureRequest & setSubsetOfAttributes(const QgsAttributeList &attrs)
Set a subset of attributes that will be fetched.
QgsFeatureRequest & setExpressionContext(const QgsExpressionContext &context)
Sets the expression context used to evaluate filter expressions.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Container of fields for a vector layer.
Qgis::FieldOrigin fieldOrigin(int fieldIdx) const
Returns the field's origin (value from an enumeration).
Gradient color ramp, which smoothly interpolates between two colors and also supports optional extra ...
double value(int index) const override
Returns relative value between [0,1] of color at specified index.
A storage object for map layers, in which the layers are owned by the store and have their lifetime b...
Base class for all map layer types.
QString source() const
Returns the source for the layer.
QString providerType() const
Returns the provider type (provider key) for this layer.
Encapsulates a QGIS project, including sets of map layers and their styles, layouts,...
static QgsProject * instance()
Returns the QgsProject singleton instance.
Q_INVOKABLE QgsMapLayer * mapLayer(const QString &layerId) const
Retrieve a pointer to a registered layer by layer ID.
Q_INVOKABLE QList< QgsMapLayer * > mapLayersByName(const QString &layerName) const
Retrieve a list of matching registered layers by layer name.
QVariantMap decodeUri(const QString &providerKey, const QString &uri)
Breaks a provider data source URI into its component paths (e.g.
static QgsProviderRegistry * instance(const QString &pluginPath=QString())
Means of accessing canonical single instance.
Contains utility functions for working with symbols and symbol layers.
static bool isNull(const QVariant &variant, bool silenceNullWarnings=false)
Returns true if the specified variant should be considered a NULL value.
Partial snapshot of vector layer's state (only the members necessary for access to features)
Represents a vector layer which manages a vector based data sets.
QgsFeatureIterator getFeatures(const QgsFeatureRequest &request=QgsFeatureRequest()) const FINAL
Queries the layer for features specified in request.
@ Unknown
Unknown/invalid format.
#define Q_NOWARN_DEPRECATED_POP
#define Q_NOWARN_DEPRECATED_PUSH
QList< int > QgsAttributeList
QPointer< QgsMapLayer > QgsWeakMapLayerPointer
Weak pointer for QgsMapLayer.