Add new methods

scrub_layer_class.py

@@ -1,6 +1,7 @@
 from qgis.core import QgsApplication, QgsField, QgsProject, \
   QgsProcessingFeedback, QgsVectorLayer, QgsVectorDataProvider, \
-  QgsExpressionContext, QgsExpressionContextUtils
+  QgsExpressionContext, QgsExpressionContextUtils, edit
+from qgis.PyQt.QtCore import QVariant
 from qgis.analysis import QgsNativeAlgorithms
 import processing
 
@@ -43,9 +44,25 @@ class ScrubLayer:
       'OUTPUT': 'Output'
     }
     processing.run("native:createspatialindex", create_spatial_index_params)
-    print(f'Creating spatial index for {self.layer_name} is completed.')
+    print(f'Creating Spatial index for {self.layer_name} is completed.')
+
+  def spatial_join(self, joining_layer_path, joined_layer_path):
+    """In QGIS, it is called 'Join attributes by Location'"""
+    params = {'INPUT': self.layer,
+              'PREDICATE': [0],
+              'JOIN': joining_layer_path,
+              'JOIN_FIELDS': [],
+              'METHOD': 0,
+              'DISCARD_NONMATCHING': False,
+              'PREFIX': '',
+              'OUTPUT': joined_layer_path}
+
+    feedback = QgsProcessingFeedback()
+    processing.run('native:joinattributesbylocation', params, feedback=feedback)
+    print(f'Spatial Join with input layer {self.layer_name} is completed.')
 
   def clip_layer(self, overlay_layer, clipped_layer):
+    """This must be tested"""
     QgsApplication.processingRegistry().addProvider(QgsNativeAlgorithms())
     clip_layer_params = {
       'INPUT': self.layer_path,
@@ -57,6 +74,55 @@ class ScrubLayer:
     processing.run("native:clip", clip_layer_params)
     print(f'Clipping of {self.layer_name} is completed.')
 
+  def merge_layers(self, layers_path, mered_layer_path):
+    pass
+
+  def multipart_to_singleparts(self):
+    pass
+
+  def split_layer(self):
+    pass
+
+  def delete_duplicates(self, deleted_duplicates_layer):
+    QgsApplication.processingRegistry().addProvider(QgsNativeAlgorithms())
+    params = {'INPUT': self.layer_path,
+              'OUTPUT': deleted_duplicates_layer}
+    processing.run("native:deleteduplicategeometries", params)
+
+  def delete_field(self, field_name):
+    QgsApplication.processingRegistry().addProvider(QgsNativeAlgorithms())
+    with edit(self.layer):
+      # Get the index of the column to delete
+      idx = self.layer.fields().indexFromName(field_name)
+
+      # Delete the field
+      self.layer.deleteAttribute(idx)
+
+      # Update layer fields
+      self.layer.updateFields()
+
+  def add_field(self, new_field_name):
+    functionalities = self.layer.dataProvider().capabilities()
+
+    if functionalities & QgsVectorDataProvider.AddAttributes:
+      new_field = QgsField(new_field_name, QVariant.Double)
+      self.layer.dataProvider().addAttributes([new_field])
+      self.layer.updateFields()
+
+  def assign_area(self, field_name):
+    self.layer.startEditing()
+    idx = self.layer.fields().indexFromName(field_name)
+
+    context = QgsExpressionContext()
+    context.appendScopes(QgsExpressionContextUtils.globalProjectLayerScopes(self.layer))
+
+    for feature in self.layer.getFeatures():
+      area = feature.geometry().area()
+      feature[idx] = area
+      self.layer.updateFeature(feature)
+
+    self.layer.commitChanges()
+
   def __str__(self):
     return f'The {self.layer_name} has {self.data_count} records.'