Abstract base class for QgsPropertyCollection like objects. More...

#include <qgspropertycollection.h>

Inheritance diagram for QgsAbstractPropertyCollection:

Public Member Functions
	QgsAbstractPropertyCollection (const QString &name=QString())
	Constructor for QgsAbstractPropertyCollection. More...

virtual	~QgsAbstractPropertyCollection ()=default

virtual void	clear ()=0
	Removes all properties from the collection. More...

virtual bool	hasActiveProperties () const =0
	Returns `true` if the collection has any active properties, or `false` if all properties within the collection are deactivated. More...

virtual bool	hasDynamicProperties () const =0
	Returns `true` if the collection has any active, non-static properties, or `false` if either all non-static properties within the collection are deactivated or if the collection only contains static properties. More...

virtual bool	hasProperty (int key) const =0
	Returns `true` if the collection contains a property with the specified key. More...

virtual bool	isActive (int key) const =0
	Returns `true` if the collection contains an active property with the specified key. More...

virtual bool	loadVariant (const QVariant &configuration, const QgsPropertiesDefinition &definitions)=0
	Loads this property collection from a QVariantMap, wrapped in a QVariant. More...

QString	name () const
	Returns the descriptive name of the property collection. More...

virtual bool	prepare (const QgsExpressionContext &context=QgsExpressionContext()) const =0
	Prepares the collection against a specified expression context. More...

virtual QgsProperty	property (int key) const =0
	Returns a matching property from the collection, if one exists. More...

virtual QSet< int >	propertyKeys () const =0
	Returns a list of property keys contained within the collection. More...

virtual bool	readXml (const QDomElement &collectionElem, const QgsPropertiesDefinition &definitions)
	Reads property collection state from an XML element. More...

virtual QSet< QString >	referencedFields (const QgsExpressionContext &context=QgsExpressionContext(), bool ignoreContext=false) const =0
	Returns the set of any fields referenced by the active properties from the collection. More...

void	setName (const QString &name)
	Sets the descriptive name for the property collection. More...

virtual QVariant	toVariant (const QgsPropertiesDefinition &definitions) const =0
	Saves this property collection to a QVariantMap, wrapped in a QVariant. More...

virtual QVariant	value (int key, const QgsExpressionContext &context, const QVariant &defaultValue=QVariant()) const =0
	Returns the calculated value of the property with the specified key from within the collection. More...

bool	valueAsBool (int key, const QgsExpressionContext &context, bool defaultValue=false, bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as an boolean. More...

QColor	valueAsColor (int key, const QgsExpressionContext &context, const QColor &defaultColor=QColor(), bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as a color. More...

QDateTime	valueAsDateTime (int key, const QgsExpressionContext &context, const QDateTime &defaultDateTime=QDateTime(), bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as a datetime. More...

double	valueAsDouble (int key, const QgsExpressionContext &context, double defaultValue=0.0, bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as a double. More...

int	valueAsInt (int key, const QgsExpressionContext &context, int defaultValue=0, bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as an integer. More...

QString	valueAsString (int key, const QgsExpressionContext &context, const QString &defaultString=QString(), bool *ok=nullptr) const
	Calculates the current value of the property with the specified key and interprets it as a string. More...

virtual bool	writeXml (QDomElement &collectionElem, const QgsPropertiesDefinition &definitions) const
	Writes the current state of the property collection into an XML element. More...

Detailed Description

Abstract base class for QgsPropertyCollection like objects.

Since: QGIS 3.0

Definition at line 41 of file qgspropertycollection.h.

Constructor & Destructor Documentation

◆ QgsAbstractPropertyCollection()

QgsAbstractPropertyCollection::QgsAbstractPropertyCollection ( const QString & name = QString() )

Constructor for QgsAbstractPropertyCollection.

The name parameter should be set to a descriptive name for the collection.

Definition at line 24 of file qgspropertycollection.cpp.

◆ ~QgsAbstractPropertyCollection()

virtual QgsAbstractPropertyCollection::~QgsAbstractPropertyCollection ( )

virtualdefault

Member Function Documentation

◆ clear()

virtual void QgsAbstractPropertyCollection::clear ( )

pure virtual

Removes all properties from the collection.

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ hasActiveProperties()

virtual bool QgsAbstractPropertyCollection::hasActiveProperties ( ) const

pure virtual

Returns true if the collection has any active properties, or false if all properties within the collection are deactivated.

See also: hasDynamicProperties()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ hasDynamicProperties()

virtual bool QgsAbstractPropertyCollection::hasDynamicProperties ( ) const

pure virtual

Returns true if the collection has any active, non-static properties, or false if either all non-static properties within the collection are deactivated or if the collection only contains static properties.

See also: hasActiveProperties()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ hasProperty()

virtual bool QgsAbstractPropertyCollection::hasProperty ( int key ) const

pure virtual

Returns true if the collection contains a property with the specified key.

Parameters

key	integer key for property. The intended use case is that a context specific enum is cast to int and used for the key value.

See also: property()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ isActive()

virtual bool QgsAbstractPropertyCollection::isActive ( int key ) const

pure virtual

Returns true if the collection contains an active property with the specified key.

Parameters

key	integer key for property to test. The intended use case is that a context specific enum is cast to int and used for the key value.

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ loadVariant()

virtual bool QgsAbstractPropertyCollection::loadVariant	(	const QVariant &	configuration,
		const QgsPropertiesDefinition &	definitions
	)

pure virtual

Loads this property collection from a QVariantMap, wrapped in a QVariant.

You can use QgsXmlUtils::readVariant to save it to an XML document.

See also: toVariant()

Implemented in QgsPropertyCollection, and QgsPropertyCollectionStack.

◆ name()

QString QgsAbstractPropertyCollection::name ( ) const

inline

Returns the descriptive name of the property collection.

See also: setName()

Definition at line 69 of file qgspropertycollection.h.

◆ prepare()

virtual bool QgsAbstractPropertyCollection::prepare ( const QgsExpressionContext & context = QgsExpressionContext() ) const

pure virtual

Prepares the collection against a specified expression context.

Calling prepare before evaluating the collection's properties multiple times allows precalculation of expensive setup tasks such as parsing expressions. Returns true if preparation was successful.

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ property()

virtual QgsProperty QgsAbstractPropertyCollection::property ( int key ) const

pure virtual

Returns a matching property from the collection, if one exists.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.

Returns: matching property, or null if no matching, active property found.

See also: hasProperty()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ propertyKeys()

virtual QSet<int> QgsAbstractPropertyCollection::propertyKeys ( ) const

pure virtual

Returns a list of property keys contained within the collection.

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ readXml()

bool QgsAbstractPropertyCollection::readXml	(	const QDomElement &	collectionElem,
		const QgsPropertiesDefinition &	definitions
	)

virtual

Reads property collection state from an XML element.

Parameters

collectionElem	source DOM element for property collection's state
definitions	property definitions

See also: writeXml()

Definition at line 108 of file qgspropertycollection.cpp.

◆ referencedFields()

virtual QSet< QString > QgsAbstractPropertyCollection::referencedFields	(	const QgsExpressionContext &	context = `QgsExpressionContext()`,
		bool	ignoreContext = `false`
	)		const

pure virtual

Returns the set of any fields referenced by the active properties from the collection.

Parameters

context	expression context the properties will be evaluated against.
ignoreContext	This parameter has been added in QGIS 3.14. When set to `true`, even fields not set in context's fields() will be reported - this is useful e.g. with vector tiles where the actual available field names may not be known beforehand.

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ setName()

void QgsAbstractPropertyCollection::setName ( const QString & name )

inline

Sets the descriptive name for the property collection.

See also: name()

Definition at line 75 of file qgspropertycollection.h.

◆ toVariant()

virtual QVariant QgsAbstractPropertyCollection::toVariant ( const QgsPropertiesDefinition & definitions ) const

pure virtual

Saves this property collection to a QVariantMap, wrapped in a QVariant.

You can use QgsXmlUtils::writeVariant to save it to an XML document.

See also: loadVariant()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ value()

virtual QVariant QgsAbstractPropertyCollection::value	(	int	key,
		const QgsExpressionContext &	context,
		const QVariant &	defaultValue = `QVariant()`
	)		const

pure virtual

Returns the calculated value of the property with the specified key from within the collection.

If you need the validity of the value (like ok provided from the valueAs* variants) refer to the property() and QgsProperty::value()

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	expression context to evaluate property against
defaultValue	default value to return if no matching, active property found or if the property value cannot be calculated

Returns: calculated property value, or default value if property could not be evaluated

See also: valueAsString(); valueAsColor(); valueAsDouble(); valueAsInt(); valueAsBool()

Implemented in QgsPropertyCollectionStack, and QgsPropertyCollection.

◆ valueAsBool()

bool QgsAbstractPropertyCollection::valueAsBool	(	int	key,
		const QgsExpressionContext &	context,
		bool	defaultValue = `false`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as an boolean.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultValue	default boolean to return if the property cannot be calculated as a boolean
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to bool

See also: value(); valueAsDateTime(); valueAsString(); valueAsColor(); valueAsDouble(); valueAsInt()

Definition at line 88 of file qgspropertycollection.cpp.

◆ valueAsColor()

QColor QgsAbstractPropertyCollection::valueAsColor	(	int	key,
		const QgsExpressionContext &	context,
		const QColor &	defaultColor = `QColor()`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as a color.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultColor	default color to return if the property cannot be calculated as a color
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to color

See also: value(); valueAsDateTime(); valueAsString(); valueAsDouble(); valueAsInt(); valueAsBool()

Definition at line 54 of file qgspropertycollection.cpp.

◆ valueAsDateTime()

QDateTime QgsAbstractPropertyCollection::valueAsDateTime	(	int	key,
		const QgsExpressionContext &	context,
		const QDateTime &	defaultDateTime = `QDateTime()`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as a datetime.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultDateTime	default datetime to return if the property cannot be calculated as a datetime
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to datetime

See also: value(); valueAsString(); valueAsColor(); valueAsDouble(); valueAsInt(); valueAsBool()

Since: QGIS 3.14

Definition at line 30 of file qgspropertycollection.cpp.

◆ valueAsDouble()

double QgsAbstractPropertyCollection::valueAsDouble	(	int	key,
		const QgsExpressionContext &	context,
		double	defaultValue = `0.0`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as a double.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultValue	default double to return if the property cannot be calculated as a double
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to double

See also: value(); valueAsDateTime(); valueAsString(); valueAsColor(); valueAsInt(); valueAsBool()

Definition at line 66 of file qgspropertycollection.cpp.

◆ valueAsInt()

int QgsAbstractPropertyCollection::valueAsInt	(	int	key,
		const QgsExpressionContext &	context,
		int	defaultValue = `0`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as an integer.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultValue	default integer to return if the property cannot be calculated as a integer
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to integer

See also: value(); valueAsDateTime(); valueAsString(); valueAsColor(); valueAsDouble(); valueAsBool()

Definition at line 77 of file qgspropertycollection.cpp.

◆ valueAsString()

QString QgsAbstractPropertyCollection::valueAsString	(	int	key,
		const QgsExpressionContext &	context,
		const QString &	defaultString = `QString()`,
		bool *	ok = `nullptr`
	)		const

Calculates the current value of the property with the specified key and interprets it as a string.

Parameters

key	integer key for property to return. The intended use case is that a context specific enum is cast to int and used for the key value.
context	QgsExpressionContext to evaluate the property for.
defaultString	default string to return if the property cannot be calculated as a string
ok	if specified, will be set to `true` if conversion was successful

Returns: value parsed to string

See also: value(); valueAsDateTime(); valueAsColor(); valueAsDouble(); valueAsInt(); valueAsBool()

Definition at line 42 of file qgspropertycollection.cpp.

◆ writeXml()

bool QgsAbstractPropertyCollection::writeXml	(	QDomElement &	collectionElem,
		const QgsPropertiesDefinition &	definitions
	)		const

virtual

Writes the current state of the property collection into an XML element.

Parameters

collectionElem	destination element for the property collection's state
definitions	property definitions

See also: readXml()

Definition at line 99 of file qgspropertycollection.cpp.

The documentation for this class was generated from the following files:

/build/qgis-3.18.1+99unstable/src/core/qgspropertycollection.h
/build/qgis-3.18.1+99unstable/src/core/qgspropertycollection.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QgsAbstractPropertyCollection()

◆ ~QgsAbstractPropertyCollection()

Member Function Documentation

◆ clear()

◆ hasActiveProperties()

◆ hasDynamicProperties()

◆ hasProperty()

◆ isActive()

◆ loadVariant()

◆ name()

◆ prepare()

◆ property()

◆ propertyKeys()

◆ readXml()

◆ referencedFields()

◆ setName()

◆ toVariant()

◆ value()

◆ valueAsBool()

◆ valueAsColor()

◆ valueAsDateTime()

◆ valueAsDouble()

◆ valueAsInt()

◆ valueAsString()

◆ writeXml()