Subgroup: Property

Class: QgsPropertyCollection¶

class qgis.core.QgsPropertyCollection¶

Bases: qgis._core.QgsAbstractPropertyCollection

A grouped map of multiple QgsProperty objects, each referenced by a integer key value.

Properties within a collection are referenced by an integer key. This is done to avoid the cost of string creation and comparisons which would be required by a string key. The intended use case is that a context specific enum is cast to int and used for the key value.

New in version 3.0: Methods

`clear`
`count`	Returns the number of properties contained within the collection.
`hasActiveProperties`
`hasDynamicProperties`
`hasProperty`
`isActive`
`loadVariant`
`name`	Returns the descriptive name of the property collection.
`prepare`
`property`	Returns a reference to a matching property from the collection, if one exists.
`propertyKeys`
`readXml`	Reads property collection state from an XML element.
`referencedFields`
`setName`	Sets the descriptive name for the property collection.
`setProperty`	Adds a property to the collection and takes ownership of it.
`toVariant`
`value`
`valueAsBool`	Calculates the current value of the property with the specified key and interprets it as an boolean.
`valueAsColor`	Calculates the current value of the property with the specified key and interprets it as a color.
`valueAsDouble`	Calculates the current value of the property with the specified key and interprets it as a double.
`valueAsInt`	Calculates the current value of the property with the specified key and interprets it as an integer.
`valueAsString`	Calculates the current value of the property with the specified key and interprets it as a string.
`writeXml`	Writes the current state of the property collection into an XML element

Attributes

clear(self)¶

count(self) → int¶: Returns the number of properties contained within the collection.

hasActiveProperties(self) → bool¶

hasDynamicProperties(self) → bool¶

hasProperty(self, key: int) → bool¶

isActive(self, key: int) → bool¶

loadVariant(self, configuration: Any, definitions: object) → bool¶

prepare(self, context: QgsExpressionContext = QgsExpressionContext()) → bool¶

property(self, key: int) → QgsProperty¶

Returns a reference to 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()

propertyKeys(self) → object¶

referencedFields(self, context: QgsExpressionContext = QgsExpressionContext()) → Set[str]¶

setProperty(self, key: int, property: QgsProperty)¶

Adds a property to the collection and takes ownership of it.

Parameters:	key – integer key for property. Any existing property with the same key will be removed

and replaced by this property. The intended use case is that a context specific enum is cast to int and used for the key value. :param property: property to add. Ownership is transferred to the collection. Setting an invalid property will remove the property from the collection.

setProperty(self, key: int, value: Any) Convience method, creates a QgsStaticProperty and stores it within the collection.

Parameters:	key – integer key for property. Any existing property with the same key will be deleted

and replaced by this property. The intended use case is that a context specific enum is cast to int and used for the key value. :param value: static value for property

toVariant(self, definitions: object) → Any¶

value(self, key: int, context: QgsExpressionContext, defaultValue: Any = None) → Any¶