Base

Import

from pyqgis_wrapper.layer.base import LayerBuilder

LayerBuilder()

Bases: typing.Generic[pyqgis_wrapper.layer.base.T]

Base class that handles layer creation.

It can be written to a file or stay in memory

Source code in pyqgis_wrapper/layer/base.py

def __init__(self):
    """ """
    self._layer: Optional[T] = None
    self._crs: Optional[QgsCoordinateReferenceSystem] = None
    self._src_layer: Optional[QgsMapLayer] = None
    self.logger = create_child_logger(__name__)

set_crs(crs)

Set layer crs

Parameters:

Name	Type	Description	Default
crs	typing.Union[str, int, qgis.core.QgsCoordinateReferenceSystem]	Coordinate reference system	required

Returns:

Type	Description
VectorLayerBuilder	self

Source code in pyqgis_wrapper/layer/base.py

def set_crs(
    self, crs: Union[str, int, QgsCoordinateReferenceSystem]
) -> LayerBuilder:
    """
    Set layer crs

    :param crs: Coordinate reference system
    :type crs: Union[str, int, QgsCoordinateReferenceSystem]

    :return: self
    :rtype: VectorLayerBuilder
    """
    crs = CRSHandler.build_crs(crs)

    if not crs.isValid():
        raise ValueError(
            "The provided Coordinate Reference System (CRS) is not valid. "
            "Please ensure it is correctly defined."
        )

    self._crs = crs

    return self

from_layer(*args, **kwargs) abstractmethod

Duplicate a layer at various degree

Source code in pyqgis_wrapper/layer/base.py

@abstractmethod
def from_layer(self, *args, **kwargs) -> LayerBuilder:
    """
    Duplicate a layer at various degree
    """

configure(*args, **kwargs) abstractmethod

Configure layer creation from scratch

Source code in pyqgis_wrapper/layer/base.py

@abstractmethod
def configure(self, *args, **kwargs) -> LayerBuilder:
    """
    Configure layer creation from scratch
    """

build() abstractmethod

Build a layer form the parameters set by from_layer or configure method.

Returns:

Type	Description
VectorLayerBuilder	self

Source code in pyqgis_wrapper/layer/base.py

@abstractmethod
def build(self) -> LayerBuilder:
    """
    Build a layer form the parameters set by from_layer or configure method.

    :return: self
    :rtype: VectorLayerBuilder
    """

save(*args, **kwargs) abstractmethod

Writes layer to a file

Source code in pyqgis_wrapper/layer/base.py

@abstractmethod
def save(self, *args, **kwargs) -> LayerBuilder:
    """
    Writes layer to a file
    """

load()

Access the layer built or/and saved

Returns:

Type	Description
QgsVectorLayer	Newly created layer

Source code in pyqgis_wrapper/layer/base.py

def load(self) -> T:
    """
    Access the layer built or/and saved

    :return: Newly created layer
    :rtype: QgsVectorLayer
    """

    if self.__class__.__name__ == "VectorLayerBuilder":
        layer = "QgsVectorLayer"
    elif self.__class__.__name__ == "RasterLayerBuilder":
        layer = "QgsRasterLayer"
    else:
        layer = "QgsMapLayer"

    if self._layer is None:
        raise RuntimeError(
            "Layer has not been built. Call `build()` before accessing the layer."
        )
    if not self._layer.isValid():
        raise ValueError(
            f"{self._layer} is not a valid {layer}. "
            "This may be due to a mismatch between the specified file extension "
            "and the chosen provider in the `save()` method."
        )

    return self._layer

clear()

Clear the internal reference to the layer. It is a clean way to access to self._layer and self._src_layer. This allow the caller to delete a saved layer for example.

For a full reset of the class state see 'reset' method

This method should be called after loading the layer with self.load or saving it with self.save

Source code in pyqgis_wrapper/layer/base.py

def clear(self):
    """
    Clear the internal reference to the layer.
    It is a clean way to access to self._layer and self._src_layer.
    This allow the caller to delete a saved layer for example.

    For a full reset of the class state see 'reset' method

    This method should be called after loading the layer
    with self.load or saving it with self.save
    """
    self._layer = None
    self._src_layer = None

reset()

Resets all internal references to their default values. This ensures that no interference occurs when building another layer with completely different parameters.

If you just want to take full ownership of the saved layer object see 'clear' method.

Source code in pyqgis_wrapper/layer/base.py

def reset(self):
    """
    Resets all internal references to their default values.
    This ensures that no interference occurs when building another layer
    with completely different parameters.

    If you just want to take full ownership of the saved layer object see 'clear' method.
    """
    self.__init__()