[processing] fix gdal_contour algorithm

Author: alexbruy

python/plugins/processing/algs/gdal/GdalUtils.py

@@ -29,7 +29,7 @@
 import subprocess
 import platform
 from qgis.PyQt.QtCore import QSettings
-from qgis.core import QgsApplication
+from qgis.core import QgsApplication, QgsVectorFileWriter
 from processing.core.ProcessingLog import ProcessingLog
 from processing.core.SilentProgress import SilentProgress
 
@@ -142,6 +142,19 @@ def getSupportedRasterExtensions():
                     allexts.append(ext)
         return allexts
 
+    @staticmethod
+    def getVectorDriverFromFileName(filename):
+        ext = os.path.splitext(filename)[1]
+        if ext == '':
+            return 'ESRI Shapefile'
+
+        formats = QgsVectorFileWriter.supportedFiltersAndFormats()
+        for k, v in formats.iteritems():
+            print k, v
+            if ext in k:
+                return v
+        return 'ESRI Shapefile'
+
     @staticmethod
     def getFormatShortNameFromFilename(filename):
         ext = filename[filename.rfind('.') + 1:]

python/plugins/processing/algs/gdal/contour.py

@@ -71,6 +71,8 @@ def defineCharacteristics(self):
                                     self.tr('Contours')))
 
     def getConsoleCommands(self):
+        output = self.getOutputValue(self.OUTPUT_VECTOR)
+        print 'OUTPUT', output
         interval = unicode(self.getParameterValue(self.INTERVAL))
         fieldName = unicode(self.getParameterValue(self.FIELD_NAME))
         extra = self.getParameterValue(self.EXTRA)
@@ -84,10 +86,15 @@ def getConsoleCommands(self):
         arguments.append('-i')
         arguments.append(interval)
 
+        driver = GdalUtils.getVectorDriverFromFileName(output)
+        print 'DRIVER', driver
+        arguments.append('-f')
+        arguments.append(driver)
+
         if extra and len(extra) > 0:
             arguments.append(extra)
 
         arguments.append(self.getParameterValue(self.INPUT_RASTER))
-        arguments.append(self.getOutputValue(self.OUTPUT_VECTOR))
+        arguments.append(output)
 
         return ['gdal_contour', GdalUtils.escapeAndJoin(arguments)]