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Constructors

Constructor

Source code in python\engine\constructors.py 
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class Constructor:

    logger = get_logger()

    def layerFromWKT(type: QgsVectorLayer, wktList: list, epsg: int):
        """
        Create a layer from a list of wkt's.

        Args:
            type (string): One of 'Point', 'Line','Polygon','MultiPoint', 'MultiLine', 'MultiPolygon'
            wktList (list of strings): List of wkt's to be added to the new layer
            epsg (integer): The epsg code corrosponding to the wkt features coordinate system.

        Returns:
            layer (QgsVectorLayer): The output layers containing the wkt's
        """

        logger.info("Creating layer from WKT")
        logger.info(f'Number of features {str(len(wktList))}, type: {type}')

        if type in ['Point', 'Line','Polygon','MultiPoint', 'MultiLine', 'MultiPolygon']:

            try:
                wkt_layer = QgsVectorLayer(f'{type}?crs=epsg:{str(epsg)}', "WKT_Layer", "Memory")

                features = []
                for elm in wktList:
                    feature = QgsFeature()
                    geom = QgsGeometry.fromWkt(elm)
                    feature.setGeometry(geom)
                    features.append(feature)
                wkt_layer.dataProvider().addFeatures(features)
                wkt_layer.updateFields()
                wkt_layer.commitChanges()

                logger.info("layerFromWKT finished")
                if layerHasFeatures(wkt_layer):
                    logger.info(f'Returning {str(wkt_layer.featureCount())} features')
                return wkt_layer

            except Exception as error:
                logger.error("An error occured in crating WKT layer")
                logger.error(f'{type(error).__name__}  –  {str(error)}')
                logger.critical("Program terminated" )
                sys.exit()
        else:
                logger.error("An error occured in crating WKT layer")
                logger.error('Unsupported type, use Point/Line/Polygon/multiPoint/MultiLine/Multipolygon' )
                logger.critical("Program terminated" )
                sys.exit()

    def bboxFromLayer(layer: str):
        """
        Create a bounding box from the extents of a given layer

        Args:
            layer (QgsVectorLayer): The layer, that the bbox is calculated uppon.

        Returns:
            layer (QgsVectorLayer): The output layer, containing the bbox from the input layer

        """
        logger.info("Extracting bbox from layer" )
        if layerHasFeatures(layer):
            logger.info(f'Processing {str(layer.featureCount())} features')
        try:
            ext = layer.extent()
            xmin = ext.xMinimum()
            xmax = ext.xMaximum()
            ymin = ext.yMinimum()
            ymax = ext.yMaximum()
            epsg = layer.crs().authid()
            data = [xmin, ymin, xmax, ymax, epsg]
            logger.info("Extract bbox finished")
            return data
        except Exception as error:
            logger.error("An error occured extracting bbox")
            logger.error(f'{type(error).__name__}  –  {str(error)}')
            logger.critical("Program terminated" )
            sys.exit()

bboxFromLayer(layer)

Create a bounding box from the extents of a given layer

Parameters:

Name Type Description Default
layer QgsVectorLayer

The layer, that the bbox is calculated uppon.

 required

Returns:

Name Type Description
layer QgsVectorLayer

The output layer, containing the bbox from the input layer
Source code in python\engine\constructors.py 
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def bboxFromLayer(layer: str):
    """
    Create a bounding box from the extents of a given layer

    Args:
        layer (QgsVectorLayer): The layer, that the bbox is calculated uppon.

    Returns:
        layer (QgsVectorLayer): The output layer, containing the bbox from the input layer

    """
    logger.info("Extracting bbox from layer" )
    if layerHasFeatures(layer):
        logger.info(f'Processing {str(layer.featureCount())} features')
    try:
        ext = layer.extent()
        xmin = ext.xMinimum()
        xmax = ext.xMaximum()
        ymin = ext.yMinimum()
        ymax = ext.yMaximum()
        epsg = layer.crs().authid()
        data = [xmin, ymin, xmax, ymax, epsg]
        logger.info("Extract bbox finished")
        return data
    except Exception as error:
        logger.error("An error occured extracting bbox")
        logger.error(f'{type(error).__name__}  –  {str(error)}')
        logger.critical("Program terminated" )
        sys.exit()

layerFromWKT(type, wktList, epsg)

Create a layer from a list of wkt's.

Parameters:

Name Type Description Default
type string

One of 'Point', 'Line','Polygon','MultiPoint', 'MultiLine', 'MultiPolygon'

 required
wktList list of strings

List of wkt's to be added to the new layer

 required
epsg integer

The epsg code corrosponding to the wkt features coordinate system.

 required

Returns:

Name Type Description
layer QgsVectorLayer

The output layers containing the wkt's
Source code in python\engine\constructors.py 
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def layerFromWKT(type: QgsVectorLayer, wktList: list, epsg: int):
    """
    Create a layer from a list of wkt's.

    Args:
        type (string): One of 'Point', 'Line','Polygon','MultiPoint', 'MultiLine', 'MultiPolygon'
        wktList (list of strings): List of wkt's to be added to the new layer
        epsg (integer): The epsg code corrosponding to the wkt features coordinate system.

    Returns:
        layer (QgsVectorLayer): The output layers containing the wkt's
    """

    logger.info("Creating layer from WKT")
    logger.info(f'Number of features {str(len(wktList))}, type: {type}')

    if type in ['Point', 'Line','Polygon','MultiPoint', 'MultiLine', 'MultiPolygon']:

        try:
            wkt_layer = QgsVectorLayer(f'{type}?crs=epsg:{str(epsg)}', "WKT_Layer", "Memory")

            features = []
            for elm in wktList:
                feature = QgsFeature()
                geom = QgsGeometry.fromWkt(elm)
                feature.setGeometry(geom)
                features.append(feature)
            wkt_layer.dataProvider().addFeatures(features)
            wkt_layer.updateFields()
            wkt_layer.commitChanges()

            logger.info("layerFromWKT finished")
            if layerHasFeatures(wkt_layer):
                logger.info(f'Returning {str(wkt_layer.featureCount())} features')
            return wkt_layer

        except Exception as error:
            logger.error("An error occured in crating WKT layer")
            logger.error(f'{type(error).__name__}  –  {str(error)}')
            logger.critical("Program terminated" )
            sys.exit()
    else:
            logger.error("An error occured in crating WKT layer")
            logger.error('Unsupported type, use Point/Line/Polygon/multiPoint/MultiLine/Multipolygon' )
            logger.critical("Program terminated" )
            sys.exit()