def copyMainLayer(layer, CRS, folder):
fields = layer.pendingFields()
layerPath = layer.dataProvider().dataSourceUri().split('|')[0]
baseName = os.path.split(layerPath)[-1].replace(".shp", '')
path = os.path.join(
folder, os.path.join('MainLayers', 'Main_' + str(baseName) + '.shp'))
if os.path.isfile(path):
return False
layerType = QGis.WKBPolygon
newlayer = QgsVectorFileWriter(path, "utf-8", fields, layerType, CRS,
"ESRI Shapefile")
for feature in layer.getFeatures():
NewFeature = QgsFeature() # Create an empty feature
NewFeature.setGeometry(feature.geometry()) # Set feature geometry
NewFeature.setAttributes(feature.attributes()) # Set attributes
# Update feature to the new layer
newlayer.addFeature(NewFeature)
del newlayer
newAttr = createNewAttrs(fields)
newlayer = QgsVectorLayer(path, QFileInfo(path).baseName(), 'ogr')
newlayer.startEditing()
# Add new attribute field to layer
newlayer.dataProvider().addAttributes(newAttr)
newlayer.commitChanges()
newlayer.startEditing()
fields = newlayer.pendingFields()
FB_idx = fields.fieldNameIndex("ForceBound")
Phx_idx = fields.fieldNameIndex("Physical")
struct_idx = fields.fieldNameIndex("Recombine")
geo_idx = fields.fieldNameIndex("geoName")
for feature in newlayer.getFeatures():
featId = feature.id()
featureFields = feature.attributes()
# If nothing is written in field "ForceBound" and "Physical", write in
# 1 in "ForceBound" to show force boundary in preset, and fill "Domain"
# in "Physical" to express the physical domain in grid generation.
if type(featureFields[FB_idx]) == QPyNullVariant:
attr = {FB_idx: 0}
newlayer.dataProvider().changeAttributeValues({featId: attr})
if type(featureFields[Phx_idx]) == QPyNullVariant:
attr = {Phx_idx: "Domain"}
newlayer.dataProvider().changeAttributeValues({featId: attr})
if type(featureFields[struct_idx]) == QPyNullVariant:
attr = {struct_idx: 1}
newlayer.dataProvider().changeAttributeValues({featId: attr})
if type(featureFields[geo_idx]) == QPyNullVariant:
name = "IS+" + str(feature.id() + 1)
attr = {geo_idx: name}
newlayer.dataProvider().changeAttributeValues({featId: attr})
newlayer.commitChanges()
return newlayer
def run(self):
"""Run method that performs all the real work"""
# show the dialog
self.dlg.show()
# Run the dialog event loop
result = self.dlg.exec_()
# See if OK was pressed
if result:
# Do something useful here - delete the line containing pass and
# substitute with your code.
filename = os.path.abspath("Sample_Data/sample_data.shp")
iface.messageBar().pushMessage("Shapefile loaded ...",
QgsMessageBar.INFO)
source_layer = iface.addVectorLayer(filename, "sample_data", "ogr")
centroid = QgsVectorLayer('Point', 'Centroid', 'memory')
fields = QgsFields()
fields.append(QgsField("code", QVariant.String))
fields.append(QgsField("x", QVariant.Double))
fields.append(QgsField("y", QVariant.Double))
# Define additional attributes already on the layer level
centroid_layer = QgsVectorFileWriter(
centroid, "UTF8", fields, QGis.WKBPoint,
QgsCoordinateReferenceSystem(4326), "ESRI Shapefile")
if centroid_layer.hasError() != QgsVectorFileWriter.NoError:
print("Error when creating centroid: ",
centroid_layer.errorMessage())
iface.messageBar().pushMessage("Feature addition failed.",
QgsMessageBar.CRITICAL)
centroid_layer.startEditing()
# Loop over all features
for source_feature in source_layer.getFeatures():
geometry = source_feature.geometry()
centroid = geometry.centroid().asPoint()
pts = [Centroid]
name = source_feature["code"]
# Create the new feature with the fields of the ogr layer
# And set geometry and attribute before adding it to the target layer
centroid_feature = QgsFeature(source_layer.fields())
centroid_feature = source_feature.attributes()
centroid_feature.setAttributes(centroid_feature)
centroid_feature.setGeometry(centroid)
centroid_feature['code'] = name
centroid_layer.addFeature(centroid_feature)
# Loop centroids to shapefile
for x, y in pts:
centroid_feature = QgsFeature()
point = QgsPoint(x, y)
centroid_feature.setGeometry(QgsGeometry.fromPoint(point))
centroid_feature.setAttributes(attrs)
prov.addFeatures([centroid_feature])
centroid_layer.commitChanges()
# Add the layer to the registry
QgsMapLayerRegistry.instance().addMapLayer(centroid_layer)
# Save centroid layer as csv format
QgsVectorFileWriter.writeAsVectorFormat(
centroid_layer,
r'extract_centroid',
"utf-8",
None,
"CSV",
layerOptions='GEOMETRY=AS_XYZ')
iface.messageBar().pushMessage("Extract centroid saved as csv ...",
QgsMessageBar.INFO)
