checking input parameters

rename_bands_algorithm.py

@@ -92,23 +92,33 @@ class RenameBandsAlgorithm(QgsProcessingAlgorithm):
         input_raster = self.parameterAsRasterLayer(parameters, self.INPUT, context)
         band_table = self.parameterAsMatrix(parameters, self.TABLE, context)
         
+        # number of columns in table is used later on, change it here if necessary
+        nb_col = 2
+        
         # get input raster path
         raster_path = input_raster.source()
         # read raster with gdal
         raster_gdal = gdal.Open(raster_path)
         # get number of bands
         nbands = raster_gdal.RasterCount
-        # TODO : check if band number = row number in band_table
+        # get number of rows in table
+        nrows = len(band_table) / nb_col
+        # check if band number = row count in band_table
+        if nbands != nrows:
+            message = 'Number of rows in table is different from number of bands in input raster'
+            feedback.reportError(QCoreApplication.translate('Rename bands', message))
+            return{}
             
         # transform band_table in a nested list, with 1 element per band, and name and order of each band
         # [['band 1', 1], ['band 2', 2], ['band 3', 3]]
-        nb_col = 2
         band_table = [band_table[n:n+nb_col] for n in range(0, len(band_table), nb_col)]
         
-        # iterate over each band to set its description
+        # iterate over each band to set its description using table input
         for band_number in range(nbands):
             band = raster_gdal.GetRasterBand(band_number + 1)
             band.SetDescription(band_table[band_number][0])
+            
+        # set band order using table input
 
         # Return the results of the algorithm as a dictionary
         return {}