[Processing] GRASS7 v.distance (implements Redmine #12817)

Author: Médéric Ribreux

python/plugins/processing/algs/grass7/description/v.distance.txt

@@ -0,0 +1,14 @@
+v.distance
+Finds the nearest element in vector map 'to' for elements in vector map 'from'.
+Vector (v.*)
+ParameterVector|from|'from' vector map|-1|False
+*ParameterString|from_type|'from' feature type (point,line,boundary,centroid,area)|point,line,area|False|False
+ParameterVector|to|'to' vector map|-1|False
+*ParameterString|to_type|'to' feature type (point,line,boundary,centroid,area)|point,line,area|False|False
+ParameterNumber|dmax|Maximum distance or -1.0 for no limit|-1.0|None|-1.0|False
+ParameterNumber|dmin|Minimum distance or -1.0 for no limit|-1.0|None|-1.0|False
+ParameterString|upload|'upload': Values describing the relation between two nearest features (cat,dist,to_x,to_y,to_along,to_angle,to_attr)|cat|False|True
+ParameterString|column|Column name(s) where values specified by 'upload' option will be uploaded|None|False|True
+ParameterTableField|to_column|Column name of nearest feature (used with upload=to_attr)|to|-1|True
+OutputVector|from_output|Nearest
+OutputVector|output|Distance

python/plugins/processing/algs/grass7/ext/v_distance.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    v_distance.py
+    -------------
+    Date                 : February 2016
+    Copyright            : (C) 2016 by Médéric Ribreux
+    Email                : medspx at medspx dot fr
+***************************************************************************
+*                                                                         *
+*   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__ = 'Médéric Ribreux'
+__date__ = 'February 2016'
+__copyright__ = '(C) 2016, Médéric Ribreux'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+import os
+
+
+def checkParameterValuesBeforeExecuting(alg):
+    """ Verify if we have the right parameters """
+    # Verify upload value
+    upload = alg.getParameterValue(u'upload')
+    if upload:
+        uploadList = [f for f in upload.split(",") if f not in ['cat', 'dist', 'to_x', 'to_y', 'to_along', 'to_angle', 'to_attr']]
+        if len(uploadList) > 0:
+            return alg.tr(u"Upload parameters should be a list of elements taken in the following values:\n'cat', 'dist', 'to_x', 'to_y', 'to_along', 'to_angle', 'to_attr'")
+        # Verifiy that we have the good number of columns
+        column = alg.getParameterValue(u'column')
+        if ((column is None or len(column) == 0) and upload) or (len(column.split(",")) != len(upload.split(","))):
+            return alg.tr(u"The number of columns and the number of upload parameters should be equal !")
+
+    # Verify from_type and to_type values
+    for geom in [u'from', u'to']:
+        geoType = alg.getParameterValue(u'{}_type'.format(geom))
+        if geoType:
+            geoTypeList = [f for f in geoType.split(",") if f not in ['point', 'line', 'boundary', 'centroid', 'area']]
+            if len(geoTypeList) > 0:
+                return alg.tr(u"Feature type for '{}' should be a list of elements taken in the following values:\n'point', 'line', 'boundary', 'centroid', 'area'".format(geom))
+
+    return None
+
+
+def processCommand(alg):
+    # We temporary remove the output 'from_output'
+    fromOutput = alg.getOutputFromName(u'from_output')
+    fromParam = alg.getParameterValue(u'from')
+    alg.exportedLayers[fromOutput.value] = alg.exportedLayers[fromParam]
+    alg.removeOutputFromName(u'from_output')
+    alg.processCommand()
+
+    # We re-add the new output
+    alg.addOutput(fromOutput)
+
+
+def processOutputs(alg):
+    # Output results ('from' table and output table)
+    for output in [u'from_output', u'output']:
+        out = alg.getOutputValue(output)
+        command = u"v.out.ogr -c type=auto -s -e input={} output=\"{}\" format=ESRI_Shapefile output_layer={}".format(
+            alg.exportedLayers[out],
+            os.path.dirname(out),
+            os.path.basename(out)[:-4]
+        )
+        alg.commands.append(command)
+        alg.outputCommands.append(command)