Class: QgsVirtualLayerTask

Initializes a virtual layer with postpone mode activated and reloads the data in a separate thread.

Added in version 3.2.

Class Hierarchy

Base classes

QgsTask	Abstract base class for long running background tasks.
QObject

Abstract Methods

run	Reloads the data.

Methods

definition	Returns the virtual layer definition.
exceptionText	Returns the exception text or an empty string if no exceptions were raised
layer	Returns the underlying virtual layer.
setExceptionText	Sets the exceptionText
takeLayer	Returns the underlying virtual layer and ownership.

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsVirtualLayerTask. See the FAQ for more details.

cancel

Cancels the pending query and the parent task.

class qgis.core.QgsVirtualLayerTask

Bases: QgsTask

__init__(definition: QgsVirtualLayerDefinition)

Constructor.

Parameters:

definition (QgsVirtualLayerDefinition) – The definition to use for initializing the virtual layer

virtual cancel(self)

Cancels the pending query and the parent task.

definition(self) → QgsVirtualLayerDefinition

Returns the virtual layer definition.

Return type:

QgsVirtualLayerDefinition

exceptionText(self) → str

Returns the exception text or an empty string if no exceptions were raised

Added in version 3.4.

Return type:

str

layer(self) → QgsVectorLayer | None

Returns the underlying virtual layer.

Return type:

Optional[QgsVectorLayer]

abstract run(self) → bool

Reloads the data.

Return type:

bool

Returns:

True if the virtual layer is valid, False otherwise.

setExceptionText(self, exceptionText: str | None)

Sets the exceptionText

Added in version 3.4.

Parameters:

exceptionText (Optional[str])

takeLayer(self) → QgsVectorLayer | None

Returns the underlying virtual layer and ownership.

Return type:

Optional[QgsVectorLayer]