[processing] Select by atribute sum algorithm

Author: alexbruy

python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

@@ -123,6 +123,7 @@
 from SetVectorStyle import SetVectorStyle
 from SetRasterStyle import SetRasterStyle
 from SelectByExpression import SelectByExpression
+from SelectByAttributeSum import SelectByAttributeSum
 from HypsometricCurves import HypsometricCurves
 from SplitLinesWithLines import SplitLinesWithLines
 from processing.algs.qgis.FieldsMapper import FieldsMapper
@@ -172,7 +173,7 @@ def __init__(self):
                         SetVectorStyle(), SetRasterStyle(),
                         SelectByExpression(), HypsometricCurves(),
                         SplitLinesWithLines(), CreateConstantRaster(),
-                        FieldsMapper(),
+                        FieldsMapper(),SelectByAttributeSum()
                         ]
 
         if hasMatplotlib:

python/plugins/processing/algs/qgis/SelectByAttributeSum.py

@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    SelectByAttributeSum.py
+    ---------------------
+    Date                 : April 2015
+    Copyright            : (C) 2015 by Alexander Bruy
+    Email                : alexander dot bruy at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Alexander Bruy'
+__date__ = 'April 2015'
+__copyright__ = '(C) 2015, Alexander Bruy'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+from qgis.core import QgsSpatialIndex, QgsFeatureRequest, QgsGeometry
+
+from processing.core.GeoAlgorithm import GeoAlgorithm
+from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
+from processing.core.parameters import ParameterVector
+from processing.core.parameters import ParameterTableField
+from processing.core.parameters import ParameterNumber
+from processing.core.outputs import OutputVector
+from processing.tools import dataobjects, vector
+
+
+class SelectByAttributeSum(GeoAlgorithm):
+    INPUT = 'INPUT'
+    FIELD = 'FIELD'
+    VALUE = 'VALUE'
+    OUTPUT = 'OUTPUT'
+
+    def defineCharacteristics(self):
+        self.name = 'Select by attribute sum'
+        self.group = 'Vector selection tools'
+
+        self.addParameter(ParameterVector(self.INPUT,
+            self.tr('Input Layer'), [ParameterVector.VECTOR_TYPE_ANY]))
+        self.addParameter(ParameterTableField(self.FIELD,
+            self.tr('Selection attribute'), self.INPUT, ParameterTableField.DATA_TYPE_NUMBER))
+        self.addParameter(ParameterNumber(self.VALUE, self.tr('Value')))
+
+        self.addOutput(OutputVector(self.OUTPUT, self.tr('Output'), True))
+
+    def processAlgorithm(self, progress):
+        fileName = self.getParameterValue(self.INPUT)
+        layer = dataobjects.getObjectFromUri(fileName)
+        fieldName = self.getParameterValue(self.FIELD)
+        value = self.getParameterValue(self.VALUE)
+
+        selected = layer.selectedFeaturesIds()
+        if len(selected) == 0:
+            GeoAlgorithmExecutionException(
+                self.tr('There is no selection in the input layer. '
+                        'Select one feature and try again.'))
+
+        ft = layer.selectedFeatures()[0]
+        geom = QgsGeometry(ft.geometry())
+        attrSum = ft[fieldName]
+
+        idx = QgsSpatialIndex(layer.getFeatures())
+        req = QgsFeatureRequest()
+        completed = False
+        while not completed:
+            intersected = idx.intersects(geom.boundingBox())
+            if len(intersected) < 0:
+                progress.setInfo(self.tr('No adjacent features found.'))
+                break
+
+            for i in intersected:
+                ft = layer.getFeatures(req.setFilterFid(i)).next()
+                tmpGeom = QgsGeometry(ft.geometry())
+                if tmpGeom.touches(geom):
+                    geom = tmpGeom.combine(geom)
+                    selected.append(i)
+                    attrSum += ft[fieldName]
+                    if attrSum >= value:
+                        completed = True
+                        break
+
+        layer.setSelectedFeatures(selected)
+        self.setOutputValue(self.OUTPUT, fileName)