diff --git a/python/plugins/processing/algs/gdal/translate.py b/python/plugins/processing/algs/gdal/translate.py
index e86ace62046..fb15aa88abb 100644
--- a/python/plugins/processing/algs/gdal/translate.py
+++ b/python/plugins/processing/algs/gdal/translate.py
@@ -109,7 +109,7 @@ class translate(GdalAlgorithm):
         outsize = str(self.getParameterValue(self.OUTSIZE))
         outsizePerc = str(self.getParameterValue(self.OUTSIZE_PERC))
         noData = self.getParameterValue(self.NO_DATA)
-        expand = self.getParameterFromName(self.EXPAND).options[self.getParameterValue(self.EXPAND)][1]
+        expand = parameters[self.EXPAND].options[self.getParameterValue(self.EXPAND)][1]
         projwin = str(self.getParameterValue(self.PROJWIN))
         if not projwin:
             projwin = QgsProcessingUtils.combineLayerExtents([inLayer])
diff --git a/python/plugins/processing/algs/grass7/ext/i.py b/python/plugins/processing/algs/grass7/ext/i.py
index cf4cef784c8..a320716b1f7 100644
--- a/python/plugins/processing/algs/grass7/ext/i.py
+++ b/python/plugins/processing/algs/grass7/ext/i.py
@@ -33,6 +33,7 @@ from processing.core.parameters import getParameterFromString
 from processing.tools.system import isWindows
 from ..Grass7Utils import Grass7Utils
 from os import path
+from copy import deepcopy
 
 
 def multipleOutputDir(alg, field, basename=None):
@@ -112,58 +113,44 @@ def regroupRasters(alg, parameters, field, groupField, subgroupField=None, extFi
     :param parameters:
     """
     # List of rasters names
+
+    new_parameters = deepcopy(parameters)
+
     rasters = alg.getParameterFromName(field)
     rastersList = rasters.value.split(';')
-    alg.parameters.remove(rasters)
+    del new_parameters[field]
 
     # Insert a i.group command
     group = getParameterFromString("ParameterString|{}|group of rasters|None|False|False".format(groupField))
-    group.value = alg.getTempFilename()
-    alg.addParameter(group)
+    new_parameters[group.name()] = alg.getTempFilename()
 
     if subgroupField:
         subgroup = getParameterFromString("ParameterString|{}|subgroup of rasters|None|False|False".format(subgroupField))
-        subgroup.value = alg.getTempFilename()
-        alg.addParameter(subgroup)
+        new_parameters[subgroup.name()] = alg.getTempFilename()
 
     command = 'i.group group={}{} input={}'.format(
-        group.value,
-        ' subgroup={}'.format(subgroup.value) if subgroupField else '',
+        new_parameters[group.name()],
+        ' subgroup={}'.format(new_parameters[subgroup.name()]) if subgroupField else '',
         ','.join([alg.exportedLayers[f] for f in rastersList])
     )
     alg.commands.append(command)
 
     # Handle external files
-    origExtParams = {}
     if subgroupField and extFile:
         for ext in list(extFile.keys()):
-            extFileName = alg.getParameterValue(ext)
+            extFileName = new_parameters[ext]
             if extFileName:
                 shortFileName = path.basename(extFileName)
                 destPath = path.join(Grass7Utils.grassMapsetFolder(),
                                      'PERMANENT',
-                                     'group', group.value,
-                                     'subgroup', subgroup.value,
+                                     'group', new_parameters[group.name()],
+                                     'subgroup', new_parameters[subgroup.name()],
                                      extFile[ext], shortFileName)
             copyFile(alg, extFileName, destPath)
-            origExtParams[ext] = extFileName
-            alg.setParameterValue(ext, shortFileName)
+            new_parameters[ext] = shortFileName
 
     # modify parameters values
-    alg.processCommand()
-
-    # Re-add input rasters
-    alg.addParameter(rasters)
-
-    # replace external files value with original value
-    for param in list(origExtParams.keys()):
-        alg.setParameterValue(param, origExtParams[param])
-
-    # Delete group:
-    alg.parameters.remove(group)
-    if subgroupField:
-        alg.parameters.remove(subgroup)
-        return group.value, subgroup.value
+    alg.processCommand(new_parameters)
 
     return group.value
 
diff --git a/python/plugins/processing/algs/grass7/ext/r_colors.py b/python/plugins/processing/algs/grass7/ext/r_colors.py
index ad73c812a00..377f36b404a 100644
--- a/python/plugins/processing/algs/grass7/ext/r_colors.py
+++ b/python/plugins/processing/algs/grass7/ext/r_colors.py
@@ -27,6 +27,7 @@ __copyright__ = '(C) 2016, Médéric Ribreux'
 __revision__ = '$Format:%H$'
 
 import os
+from copy import deepcopy
 
 
 def checkParameterValuesBeforeExecuting(alg):
@@ -74,32 +75,29 @@ def processInputs(alg):
 
 def processCommand(alg, parameters):
     # remove output before processCommand
+    new_parameters = deepcopy(parameters)
+
     output = alg.getOutputFromName('output_dir')
     alg.removeOutputFromName('output_dir')
     color = alg.getParameterFromName('color')
-    if color.value == 0:
-        alg.parameters.remove(color)
+    if new_parameters[color.name()] == 0:
+        del new_parameters[color.name()]
 
     # Handle rules
     txtRules = alg.getParameterFromName('rules_txt')
-    if txtRules.value:
+    if new_parameters[txtRules.name()]:
         # Creates a temporary txt file
         tempRulesName = alg.getTempFilename()
 
         # Inject rules into temporary txt file
         with open(tempRulesName, "w") as tempRules:
-            tempRules.write(txtRules.value)
+            tempRules.write(new_parameters[txtRules.name()])
 
         # Use temporary file as rules file
-        alg.setParameterValue('rules', tempRulesName)
-        alg.parameters.remove(txtRules)
+        new_parameters['rules'] = tempRulesName
+        del new_parameters[textRules.name()]
 
-    alg.processCommand()
-
-    # re-add the previous output
-    alg.addOutput(output)
-    alg.addParameter(color)
-    alg.addParameter(txtRules)
+    alg.processCommand(new_parameters)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li.py b/python/plugins/processing/algs/grass7/ext/r_li.py
index 5ea8fd148d5..51e00a55d00 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li.py
@@ -29,6 +29,7 @@ import shutil
 from processing.tools.system import isWindows, mkdir
 from processing.core.parameters import getParameterFromString
 import os
+from copy import deepcopy
 
 # for MS-Windows users who have MBCS chars in their name:
 if os.name == 'nt':
@@ -83,29 +84,33 @@ def checkMovingWindow(alg, outputTxt=False):
     return None
 
 
-def configFile(alg, outputTxt=False):
-    """ Handle inline configuration """
+def configFile(alg, parameters, outputTxt=False):
+    """ Handle inline configuration
+    :param parameters:
+    """
     # Where is the GRASS7 user directory ?
+
+    new_parameters = deepcopy(parameters)
+
     userGrass7Path = rliPath()
     if not os.path.isdir(userGrass7Path):
         mkdir(userGrass7Path)
     if not os.path.isdir(os.path.join(userGrass7Path, 'output')):
         mkdir(os.path.join(userGrass7Path, 'output'))
-    origConfigFile = alg.getParameterValue('config')
+    origConfigFile = new_parameters['config']
 
     # Handle inline configuration
-    configTxt = alg.getParameterFromName('config_txt')
-    if configTxt.value:
+    if new_parameters['config_txt']:
         # Creates a temporary txt file in user r.li directory
         tempConfig = alg.getTempFilename()
         configFilePath = os.path.join(userGrass7Path, tempConfig)
         # Inject rules into temporary txt file
         with open(configFilePath, "w") as f:
-            f.write(configTxt.value)
+            f.write(new_parameters['config_txt'])
 
         # Use temporary file as rules file
-        alg.setParameterValue('config', os.path.basename(configFilePath))
-        alg.parameters.remove(configTxt)
+        new_parameters['config'] = os.path.basename(configFilePath)
+        del new_parameters['config_txt']
 
     # If we have a configuration file, we need to copy it into user dir
     if origConfigFile:
@@ -114,26 +119,21 @@ def configFile(alg, outputTxt=False):
         shutil.copy(origConfigFile, configFilePath)
 
         # Change the parameter value
-        alg.setParameterValue('config', os.path.basename(configFilePath))
+        new_parameters['config'] = os.path.basename(configFilePath)
 
     origOutput = alg.getOutputFromName('output')
-    if outputTxt:
+    if new_parameters['output']:
         param = getParameterFromString("ParameterString|output|txt output|None|False|True")
-        param.value = os.path.basename(origOutput.value)
-        alg.addParameter(param)
+        new_parameters[param.name()] = origOutput.value
         alg.removeOutputFromName('output')
 
-    alg.processCommand()
+    alg.processCommand(new_parameters)
 
     # Remove Config file:
     removeConfigFile(alg)
 
     # re-add configTxt
-    alg.addParameter(configTxt)
-    alg.setParameterValue('config', origConfigFile)
     if outputTxt:
-        for param in [f for f in alg.parameters if f.name == 'output']:
-            alg.parameters.remove(param)
         alg.addOutput(origOutput)
 
 
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_cwed.py b/python/plugins/processing/algs/grass7/ext/r_li_cwed.py
index be7a3a3c4f1..44b01a061a8 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_cwed.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_cwed.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_cwed_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_cwed_ascii.py
index ce3111ea298..38d9230c437 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_cwed_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_cwed_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_dominance.py b/python/plugins/processing/algs/grass7/ext/r_li_dominance.py
index 288b435d783..89a511d07f2 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_dominance.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_dominance.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_dominance_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_dominance_ascii.py
index 4d1a7b2a451..224e61a1881 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_dominance_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_dominance_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_edgedensity.py b/python/plugins/processing/algs/grass7/ext/r_li_edgedensity.py
index 1760fab2947..1fb4e8f82af 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_edgedensity.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_edgedensity.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_edgedensity_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_edgedensity_ascii.py
index 1a06254e0de..4517b6df50b 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_edgedensity_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_edgedensity_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_mpa.py b/python/plugins/processing/algs/grass7/ext/r_li_mpa.py
index 12fcadee99a..f3c0ebd6422 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_mpa.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_mpa.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_mpa_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_mpa_ascii.py
index a82f8bad431..afffe6e6981 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_mpa_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_mpa_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_mps.py b/python/plugins/processing/algs/grass7/ext/r_li_mps.py
index 5d93a3f974e..c79632deec9 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_mps.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_mps.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_mps_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_mps_ascii.py
index 5a6790b937e..34bf9e74fc1 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_mps_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_mps_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_orig.py b/python/plugins/processing/algs/grass7/ext/r_li_orig.py
index 31918ae2350..9995eecd999 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_orig.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_orig.py
@@ -28,6 +28,7 @@ __revision__ = '$Format:%H$'
 import shutil
 from processing.tools.system import isWindows, userFolder, mkdir
 from os import path
+from copy import deepcopy
 
 
 def rliPath():
@@ -73,26 +74,29 @@ def checkMovingWindow(alg):
     return None
 
 
-def configFile(alg, outputTxt=False):
-    """ Handle inline configuration """
+def configFile(alg, parameters, outputTxt=False):
+    """ Handle inline configuration
+    :param parameters:
+    """
+    new_parameters = deepcopy(parameters)
+
     # Where is the GRASS7 user directory ?
     userGrass7Path = rliPath()
     mkdir(userGrass7Path)
-    origConfigFile = alg.getParameterValue('config')
+    origConfigFile = new_parameters['config']
 
     # Handle inline configuration
-    configTxt = alg.getParameterFromName('config_txt')
-    if configTxt.value:
+    if new_parameters['config_txt']:
         # Creates a temporary txt file in user r.li directory
         tempConfig = alg.getTempFilename()
         configFilePath = path.join(userGrass7Path, tempConfig)
         # Inject rules into temporary txt file
         with open(configFilePath, "w") as f:
-            f.write(configTxt.value)
+            f.write(new_parameters['config_txt'])
 
         # Use temporary file as rules file
-        alg.setParameterValue('config', configFilePath)
-        alg.parameters.remove(configTxt)
+        new_parameters['config'] = configFilePath
+        del new_parameters['config_txt']
 
     # If we have a configuration file, we need to copy it into user dir
     if origConfigFile:
@@ -101,21 +105,17 @@ def configFile(alg, outputTxt=False):
         shutil.copy(origConfigFile, configFilePath)
 
         # Change the parameter value
-        alg.setParameterValue('config', configFilePath)
+        new_parameters['config'] = configFilePath
 
     if outputTxt:
         origOutput = alg.getOutputValue('output')
         alg.setOutputValue('output', path.basename(origOutput))
 
-    alg.processCommand()
+    alg.processCommand(new_parameters)
 
     # Remove Config file:
     removeConfigFile(alg)
 
-    # re-add configTxt
-    alg.addParameter(configTxt)
-    alg.setParameterValue('config', origConfigFile)
-
 
 def moveOutputTxtFile(alg):
     # Find output file name:
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padcv.py b/python/plugins/processing/algs/grass7/ext/r_li_padcv.py
index 35d914248cc..65a351db319 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padcv.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padcv.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padcv_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_padcv_ascii.py
index 93ae202cb1e..1ca1547fb2e 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padcv_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padcv_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padrange.py b/python/plugins/processing/algs/grass7/ext/r_li_padrange.py
index a16d0acdf0a..942dce3615b 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padrange.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padrange.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padrange_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_padrange_ascii.py
index e011219fbf6..4d37a2af1d8 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padrange_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padrange_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padsd.py b/python/plugins/processing/algs/grass7/ext/r_li_padsd.py
index 59e3164d3c8..5afe277f52a 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padsd.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padsd.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_padsd_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_padsd_ascii.py
index 891dc221edd..99a7f78886c 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_padsd_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_padsd_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_patchdensity.py b/python/plugins/processing/algs/grass7/ext/r_li_patchdensity.py
index 78a02ccf363..72f69fe6fcf 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_patchdensity.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_patchdensity.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_patchnum.py b/python/plugins/processing/algs/grass7/ext/r_li_patchnum.py
index 94ee8b10467..759e5c0aa24 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_patchnum.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_patchnum.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_patchnum_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_patchnum_ascii.py
index fea7e507194..361e2144c5f 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_patchnum_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_patchnum_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_pielou.py b/python/plugins/processing/algs/grass7/ext/r_li_pielou.py
index 458d6eecdbb..28ef305b0ea 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_pielou.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_pielou.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_pielou_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_pielou_ascii.py
index b43a27e8b67..6a0cede4b9b 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_pielou_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_pielou_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_renyi.py b/python/plugins/processing/algs/grass7/ext/r_li_renyi.py
index 15696a4ba20..57b5112ac9c 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_renyi.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_renyi.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_renyi_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_renyi_ascii.py
index cd011448e59..e9b190bebc4 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_renyi_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_renyi_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_richness.py b/python/plugins/processing/algs/grass7/ext/r_li_richness.py
index 392d3e1cbd4..9f03b4408a7 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_richness.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_richness.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_richness_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_richness_ascii.py
index c0cffd16300..1368520259a 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_richness_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_richness_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_shannon.py b/python/plugins/processing/algs/grass7/ext/r_li_shannon.py
index a8e450bf251..a83dc6016af 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_shannon.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_shannon.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_shannon_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_shannon_ascii.py
index 047940644ae..14eee682f3c 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_shannon_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_shannon_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_shape.py b/python/plugins/processing/algs/grass7/ext/r_li_shape.py
index 2a4fc580f52..daf7eef50fe 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_shape.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_shape.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_shape_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_shape_ascii.py
index 733835fb297..1841b10d12c 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_shape_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_shape_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_simpson.py b/python/plugins/processing/algs/grass7/ext/r_li_simpson.py
index eae2abbe665..50f2aa31c7d 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_simpson.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_simpson.py
@@ -34,4 +34,4 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg)
+    configFile(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/r_li_simpson_ascii.py b/python/plugins/processing/algs/grass7/ext/r_li_simpson_ascii.py
index 1956303a3db..0e7d8cd8f89 100644
--- a/python/plugins/processing/algs/grass7/ext/r_li_simpson_ascii.py
+++ b/python/plugins/processing/algs/grass7/ext/r_li_simpson_ascii.py
@@ -34,7 +34,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    configFile(alg, True)
+    configFile(alg, parameters, True)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/v_net.py b/python/plugins/processing/algs/grass7/ext/v_net.py
index 48c4b341016..177dfe86215 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net.py
@@ -30,31 +30,31 @@ __copyright__ = '(C) 2015, Médéric Ribreux'
 __revision__ = '$Format:%H$'
 
 import os
+from copy import deepcopy
 
 
-def incorporatePoints(alg, pointLayerName=u'points', networkLayerName=u'input'):
+def incorporatePoints(alg, parameters, pointLayerName=u'points', networkLayerName=u'input'):
     """
     incorporate points with lines to form a GRASS network
     """
-    paramsToDelete = []
+    new_parameters = deepcopy(parameters)
 
     # Create an intermediate GRASS layer which is the combination of network + centers
     intLayer = alg.getTempFilename()
 
     # Grab the point layer and delete this parameter (not used by v.net.alloc)
-    pointLayer = alg.getParameterValue(pointLayerName)
+    pointLayer = new_parameters[pointLayerName]
     if pointLayer:
         pointLayer = alg.exportedLayers[pointLayer]
-        paramsToDelete.append(alg.getParameterFromName(u'points'))
+        new_parameters['points'] = pointLayer
 
     # Grab the network layer and tell to v.net.alloc to use the temp layer instead
-    lineLayer = alg.getParameterValue(networkLayerName)
+    lineLayer = new_parameters[networkLayerName]
     if lineLayer:
         lineLayer = alg.exportedLayers[lineLayer]
-        alg.setParameterValue(networkLayerName, intLayer)
+        new_parameters[networkLayerName] = lineLayer
 
-    threshold = alg.getParameterValue(u'threshold')
-    paramsToDelete.append(alg.getParameterFromName(u'threshold'))
+    threshold = parameters['threshold']
 
     # Create the v.net connect command for point layer integration
     command = u"v.net -s input={} points={} out={} op=connect threshold={}".format(
@@ -65,15 +65,7 @@ def incorporatePoints(alg, pointLayerName=u'points', networkLayerName=u'input'):
     command = u"v.db.connect -o map={} table={} layer=2".format(intLayer, pointLayer)
     alg.commands.append(command)
 
-    # Delete some unnecessary parameters
-    for param in paramsToDelete:
-        alg.parameters.remove(param)
-
-    alg.processCommand()
-
-    # Bring back the parameters:
-    for param in paramsToDelete:
-        alg.parameters.append(param)
+    alg.processCommand(new_parameters)
 
 
 def variableOutput(alg, params, nocats=True):
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_alloc.py b/python/plugins/processing/algs/grass7/ext/v_net_alloc.py
index 201de8bbb43..c1d2d1c0fc2 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_alloc.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_alloc.py
@@ -30,7 +30,7 @@ from .v_net import incorporatePoints, variableOutput
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_allpairs.py b/python/plugins/processing/algs/grass7/ext/v_net_allpairs.py
index c4ae9860da7..a66e636943e 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_allpairs.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_allpairs.py
@@ -30,4 +30,4 @@ from .v_net import incorporatePoints
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_connectivity.py b/python/plugins/processing/algs/grass7/ext/v_net_connectivity.py
index f54f43c916e..5a947046ae8 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_connectivity.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_connectivity.py
@@ -44,7 +44,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_distance.py b/python/plugins/processing/algs/grass7/ext/v_net_distance.py
index a4b57677deb..457ac0f9c17 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_distance.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_distance.py
@@ -27,6 +27,7 @@ __revision__ = '$Format:%H$'
 
 
 from processing.core.parameters import getParameterFromString
+from copy import deepcopy
 
 
 def processCommand(alg, parameters):
@@ -36,12 +37,12 @@ def processCommand(alg, parameters):
     * Delete the threshold parameter.
     * If where statement, connect to the db
     """
-    paramsToDelete = []
+    new_parameters = deepcopy(parameters)
 
     # Grab the threshold value for our v.net connect command
     threshold = alg.getParameterValue(u'threshold')
     if threshold:
-        paramsToDelete.append(alg.getParameterFromName(u'threshold'))
+        del new_parameters['threshold']
 
     # Grab the network layer and tell to v.net.alloc to use the temp layer instead
     line_layer = alg.getParameterValue(u'input')
@@ -57,7 +58,7 @@ def processCommand(alg, parameters):
         point_layer = alg.getParameterValue(layer + u'_points')
         if point_layer:
             point_layer = alg.exportedLayers[point_layer]
-            paramsToDelete.append(alg.getParameterFromName(layer + u'_points'))
+            del new_parameters[layer + u'_points']
 
         # Create the v.net connect command for point layer integration
         command = u"v.net -s input={} points={} out={} op=connect threshold={} arc_layer=1 node_layer={}".format(line_layer, point_layer, intLayer, threshold, i + 2)
@@ -69,24 +70,11 @@ def processCommand(alg, parameters):
         if not parameter:
             parameter = getParameterFromString(u'ParameterNumber|{0}_layer|{0} layer number|1|3|2|False'.format(layer))
             alg.addParameter(parameter)
-        parameter.setValue(i + 2)
+        new_parameters[parameter.name()] = i + 2
 
         # Make the connection with attribute table
         command = u"v.db.connect -o map={} table={} layer={}".format(line_layer, point_layer, i + 2)
         alg.commands.append(command)
 
-    alg.setParameterValue(u'input', line_layer)
-
-    # Delete some unnecessary parameters
-    for param in paramsToDelete:
-        alg.parameters.remove(param)
-
-    alg.processCommand(parameters, context)
-
-    # Bring back the parameters:
-    for param in paramsToDelete:
-        alg.parameters.append(param)
-
-    # Delete from_layer and to_layer
-    for word in [u'from', u'to']:
-        alg.parameters.remove(alg.getParameterFromName(u'{}_layer'.format(word)))
+    new_parameters['input'] = line_layer
+    alg.processCommand(new_parameters, context)
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_flow.py b/python/plugins/processing/algs/grass7/ext/v_net_flow.py
index 69e176b6d49..fa34a1ff4e5 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_flow.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_flow.py
@@ -44,7 +44,7 @@ def checkParameterValuesBeforeExecuting(alg):
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
 
 
 def processOutputs(alg):
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_iso.py b/python/plugins/processing/algs/grass7/ext/v_net_iso.py
index 1f04a6bdd96..974fda51587 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_iso.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_iso.py
@@ -29,4 +29,4 @@ from .v_net import incorporatePoints
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_path.py b/python/plugins/processing/algs/grass7/ext/v_net_path.py
index 09d34533e5d..9c5286274c3 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_path.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_path.py
@@ -29,4 +29,4 @@ from .v_net import incorporatePoints
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_salesman.py b/python/plugins/processing/algs/grass7/ext/v_net_salesman.py
index dd32b7e9cfc..720626bae64 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_salesman.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_salesman.py
@@ -27,10 +27,12 @@ __revision__ = '$Format:%H$'
 
 from processing.core.parameters import getParameterFromString
 from .v_net import incorporatePoints
+from copy import deepcopy
 
 
 def processCommand(alg, parameters):
     # We temporary remove the output 'sequence'
+    new_parameters = deepcopy(parameters)
     sequence = alg.getOutputFromName(u'sequence')
     sequenceFile = alg.getOutputValue(u'sequence')
     alg.exportedLayers[sequence.value] = sequence.name + alg.uniqueSuffix
@@ -38,12 +40,10 @@ def processCommand(alg, parameters):
 
     # We create a new parameter with the same name
     param = getParameterFromString(u"ParameterString|sequence|sequence|None|False|False")
-    param.setValue(sequenceFile)
-    alg.addParameter(param)
+    new_parameters[param.name()] = sequenceFile
 
     # Let's do the incorporation and command generation
-    incorporatePoints(alg)
+    incorporatePoints(alg, new_parameters)
 
     # then we delete the input parameter and add the old output
-    alg.parameters.remove(param)
     alg.addOutput(sequence)
diff --git a/python/plugins/processing/algs/grass7/ext/v_net_steiner.py b/python/plugins/processing/algs/grass7/ext/v_net_steiner.py
index f92b9f4d476..2d90b72dec4 100644
--- a/python/plugins/processing/algs/grass7/ext/v_net_steiner.py
+++ b/python/plugins/processing/algs/grass7/ext/v_net_steiner.py
@@ -29,4 +29,4 @@ from .v_net import incorporatePoints
 
 
 def processCommand(alg, parameters):
-    incorporatePoints(alg)
+    incorporatePoints(alg, parameters)
diff --git a/python/plugins/processing/algs/saga/SagaAlgorithm.py b/python/plugins/processing/algs/saga/SagaAlgorithm.py
index 5b1a30ec56f..a05bd7ac624 100644
--- a/python/plugins/processing/algs/saga/SagaAlgorithm.py
+++ b/python/plugins/processing/algs/saga/SagaAlgorithm.py
@@ -145,38 +145,38 @@ class SagaAlgorithm(GeoAlgorithm):
 
         # 1: Export rasters to sgrd and vectors to shp
         # Tables must be in dbf format. We check that.
-        for param in self.parameters:
+        for param in self.parameterDefinitions():
             if isinstance(param, ParameterRaster):
-                if param.value is None:
+                if param.name() not in parameters or parameters[param.name()] is None:
                     continue
-                if param.value.endswith('sdat'):
-                    param.value = param.value[:-4] + "sgrd"
-                elif not param.value.endswith('sgrd'):
-                    exportCommand = self.exportRasterLayer(param.value)
+                if parameters[param.name()].endswith('sdat'):
+                    parameters[param.name()] = parameters[param.name()][:-4] + "sgrd"
+                elif not parameters[param.name()].endswith('sgrd'):
+                    exportCommand = self.exportRasterLayer(parameters[param.name()])
                     if exportCommand is not None:
                         commands.append(exportCommand)
             if isinstance(param, ParameterVector):
-                if param.value is None:
+                if param.name() not in parameters or parameters[param.name()] is None:
                     continue
-                layer = QgsProcessingUtils.mapLayerFromString(param.value, context, False)
+                layer = QgsProcessingUtils.mapLayerFromString(parameters[param.name()], context, False)
                 if layer:
                     filename = dataobjects.exportVectorLayer(layer)
                     self.exportedLayers[param.value] = filename
-                elif not param.value.endswith('shp'):
+                elif not parameteres[param.name()].endswith('shp'):
                     raise GeoAlgorithmExecutionException(
                         self.tr('Unsupported file format'))
             if isinstance(param, ParameterTable):
-                if param.value is None:
+                if param.name() not in parameters or parameters[param.name()] is None:
                     continue
-                table = QgsProcessingUtils.mapLayerFromString(param.value, context, False)
+                table = QgsProcessingUtils.mapLayerFromString(parameters[param.name()], context, False)
                 if table:
                     filename = dataobjects.exportTable(table)
-                    self.exportedLayers[param.value] = filename
-                elif not param.value.endswith('shp'):
+                    self.exportedLayers[parameters[param.name()]] = filename
+                elif not parameters[param.name()].endswith('shp'):
                     raise GeoAlgorithmExecutionException(
                         self.tr('Unsupported file format'))
             if isinstance(param, ParameterMultipleInput):
-                if param.value is None:
+                if param.name() not in parameters or parameters[param.name()] is None:
                     continue
                 layers = param.value.split(';')
                 if layers is None or len(layers) == 0:
@@ -212,23 +212,23 @@ class SagaAlgorithm(GeoAlgorithm):
         command = self.undecoratedGroup + ' "' + self.cmdname + '"'
         command += ' ' + ' '.join(self.hardcodedStrings)
 
-        for param in self.parameters:
-            if param.value is None:
+        for param in self.parameterDefinitions():
+            if not param.name() in parameters or parameters[param.name()] is None:
                 continue
             if isinstance(param, (ParameterRaster, ParameterVector, ParameterTable)):
-                value = param.value
+                value = parameters[param.name()]
                 if value in list(self.exportedLayers.keys()):
                     command += ' -' + param.name() + ' "' \
                         + self.exportedLayers[value] + '"'
                 else:
                     command += ' -' + param.name() + ' "' + value + '"'
             elif isinstance(param, ParameterMultipleInput):
-                s = param.value
+                s = parameters[param.name()]
                 for layer in list(self.exportedLayers.keys()):
                     s = s.replace(layer, self.exportedLayers[layer])
                 command += ' -' + param.name() + ' "' + s + '"'
             elif isinstance(param, ParameterBoolean):
-                if param.value:
+                if parameters[param.name()]:
                     command += ' -' + param.name().strip() + " true"
                 else:
                     command += ' -' + param.name().strip() + " false"
@@ -236,7 +236,7 @@ class SagaAlgorithm(GeoAlgorithm):
                 tempTableFile = getTempFilename('txt')
                 with open(tempTableFile, 'w') as f:
                     f.write('\t'.join([col for col in param.cols]) + '\n')
-                    values = param.value.split(',')
+                    values = parameters[param.name()].split(',')
                     for i in range(0, len(values), 3):
                         s = values[i] + '\t' + values[i + 1] + '\t' + values[i + 2] + '\n'
                         f.write(s)
@@ -244,9 +244,9 @@ class SagaAlgorithm(GeoAlgorithm):
             elif isinstance(param, ParameterExtent):
                 # 'We have to substract/add half cell size, since SAGA is
                 # center based, not corner based
-                halfcell = self.getOutputCellsize() / 2
+                halfcell = self.getOutputCellsize(parameters) / 2
                 offset = [halfcell, -halfcell, halfcell, -halfcell]
-                values = param.value.split(',')
+                values = parameters[param.name()].split(',')
                 for i in range(4):
                     command += ' -' + self.extentParamNames[i] + ' ' \
                         + str(float(values[i]) + offset[i])
@@ -310,15 +310,16 @@ class SagaAlgorithm(GeoAlgorithm):
         else:
             return commands
 
-    def getOutputCellsize(self):
+    def getOutputCellsize(self, parameters):
         """Tries to guess the cell size of the output, searching for
         a parameter with an appropriate name for it.
+        :param parameters:
         """
 
         cellsize = 0
-        for param in self.parameters:
-            if param.value is not None and param.name == 'USER_SIZE':
-                cellsize = float(param.value)
+        for param in self.parameterDefinitions():
+            if param.name() in parameters and param.name() == 'USER_SIZE':
+                cellsize = float(parameters[param.name()])
                 break
         return cellsize
 
diff --git a/python/plugins/processing/core/GeoAlgorithm.py b/python/plugins/processing/core/GeoAlgorithm.py
index d35ce04bbb3..4e89003af2e 100755
--- a/python/plugins/processing/core/GeoAlgorithm.py
+++ b/python/plugins/processing/core/GeoAlgorithm.py
@@ -55,9 +55,6 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
     def __init__(self):
         super().__init__()
 
-        # Parameters needed by the algorithm
-        self.parameters = list()
-
         # Outputs generated by the algorithm
         self.outputs = list()
 
@@ -241,7 +238,7 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
     def setOutputCRS(self):
         context = dataobjects.createContext()
         layers = QgsProcessingUtils.compatibleLayers(QgsProject.instance())
-        for param in self.parameters:
+        for param in self.parameterDefinitions():
             if isinstance(param, (ParameterRaster, ParameterVector, ParameterMultipleInput)):
                 if param.value:
                     if isinstance(param, ParameterMultipleInput):
@@ -265,23 +262,6 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
         except:
             pass
 
-    def resolveDataObjects(self):
-        layers = QgsProcessingUtils.compatibleLayers(QgsProject.instance())
-        for param in self.parameters:
-            if isinstance(param, (ParameterRaster, ParameterVector, ParameterTable,
-                                  ParameterMultipleInput)):
-                if param.value:
-                    if isinstance(param, ParameterMultipleInput):
-                        inputlayers = param.value.split(';')
-                    else:
-                        inputlayers = [param.value]
-                    for i, inputlayer in enumerate(inputlayers):
-                        for layer in layers:
-                            if layer.name() == inputlayer:
-                                inputlayers[i] = layer.source()
-                                break
-                    param.setValue(";".join(inputlayers))
-
     def checkInputCRS(self, context=None):
         """It checks that all input layers use the same CRS. If so,
         returns True. False otherwise.
@@ -289,7 +269,7 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
         if context is None:
             context = dataobjects.createContext()
         crsList = []
-        for param in self.parameters:
+        for param in self.parameterDefinitions():
             if isinstance(param, (ParameterRaster, ParameterVector, ParameterMultipleInput)):
                 if param.value:
                     if isinstance(param, ParameterMultipleInput):
@@ -312,11 +292,6 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
         if isinstance(param, Parameter):
             self.parameters.append(param)
 
-    def setParameterValue(self, paramName, value):
-        for param in self.parameters:
-            if param.name == paramName:
-                return param.setValue(value)
-
     def setOutputValue(self, outputName, value):
         for out in self.outputs:
             if out.name == outputName:
@@ -337,16 +312,6 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
             d[out.name] = out.value
         return d
 
-    def __str__(self):
-        s = 'ALGORITHM: ' + self.name() + '\n'
-        for param in self.parameters:
-            s += '\t' + str(param) + '\n'
-        for out in self.outputs:
-            if not out.flags() & QgsProcessingParameterDefinition.FlagHidden:
-                s += '\t' + str(out) + '\n'
-        s += '\n'
-        return s
-
     def removeOutputFromName(self, name):
         for out in self.outputs:
             if out.name == name:
@@ -357,11 +322,6 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
             if out.name == name:
                 return out
 
-    def getParameterFromName(self, name):
-        for param in self.parameters:
-            if param.name == name:
-                return param
-
     def getParameterValue(self, name):
         for param in self.parameters:
             if param.name == name:
@@ -383,7 +343,7 @@ class GeoAlgorithm(QgsProcessingAlgorithm):
         """
 
         s = 'processing.run("' + self.id() + '",'
-        for param in self.parameters:
+        for param in self.parameterDefinitions():
             s += param.getValueAsCommandLineParameter() + ','
         for out in self.outputs:
             if not out.flags() & QgsProcessingParameterDefinition.FlagHidden:
diff --git a/python/plugins/processing/core/parameters.py b/python/plugins/processing/core/parameters.py
index 9d5e81ff130..93e3cf3b73a 100644
--- a/python/plugins/processing/core/parameters.py
+++ b/python/plugins/processing/core/parameters.py
@@ -83,22 +83,6 @@ class Parameter(object):
                  metadata={}):
         self.value = default
 
-    def setValue(self, obj):
-        """
-        Sets the value of the parameter.
-
-        Returns true if the value passed is correct for the type
-        of parameter.
-        """
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        self.value = str(obj)
-        return True
-
     def __str__(self):
         return u'{} <{}>'.format(self.name(), self.__class__.__name__)
 
@@ -123,26 +107,9 @@ class Parameter(object):
 
 class ParameterBoolean(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.BooleanWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', default=None, optional=False, metadata={}):
         Parameter.__init__(self, name, description, parseBool(default), optional, metadata)
 
-    def setValue(self, value):
-        if value is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(value, str):
-            self.value = str(value).lower() == str(True).lower()
-        else:
-            self.value = bool(value)
-        return True
-
     def getAsScriptCode(self):
         param_type = ''
         if self.flags() & QgsProcessingParameterDefinition.FlagOptional:
@@ -169,10 +136,6 @@ class ParameterBoolean(Parameter):
 
 class ParameterCrs(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.CrsWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', default=None, optional=False, metadata={}):
         '''The value is a string that uniquely identifies the
         coordinate reference system. Typically it is the auth id of the CRS
@@ -182,35 +145,6 @@ class ParameterCrs(Parameter):
         if self.value == 'ProjectCrs':
             self.value = QgsProject.instance().crs().authid()
 
-    def setValue(self, value):
-        context = dataobjects.createContext()
-        if not bool(value):
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(value, QgsCoordinateReferenceSystem):
-            self.value = value.authid()
-            return True
-        if isinstance(value, QgsMapLayer):
-            self.value = value.crs().authid()
-            return True
-        try:
-            layer = QgsProcessingUtils.mapLayerFromString(value, context)
-            if layer is not None:
-                self.value = layer.crs().authid()
-                return True
-        except:
-            pass
-        if value == 'ProjectCrs':
-            self.value = QgsProject.instance().crs().authid()
-            return True
-
-        # TODO: check it is a valid authid
-        self.value = value
-        return True
-
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"'
 
@@ -248,10 +182,6 @@ class ParameterDataObject(Parameter):
 
 class ParameterExtent(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.ExtentWidgetWrapper'
-    }
-
     USE_MIN_COVERING_EXTENT = 'USE_MIN_COVERING_EXTENT'
 
     def __init__(self, name='', description='', default=None, optional=True):
@@ -259,43 +189,6 @@ class ParameterExtent(Parameter):
         # The value is a string in the form "xmin, xmax, ymin, ymax"
         self.skip_crs_check = False
 
-    def setValue(self, value):
-        context = dataobjects.createContext()
-        if not value:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(value, QgsMapLayer):
-            rect = value.extent()
-            self.value = '{},{},{},{}'.format(
-                rect.xMinimum(), rect.xMaximum(), rect.yMinimum(), rect.yMaximum())
-            return True
-
-        try:
-            layer = QgsProcessingUtils.mapLayerFromString(value, context)
-            if layer is not None:
-                rect = layer.extent()
-                self.value = '{},{},{},{}'.format(
-                    rect.xMinimum(), rect.xMaximum(), rect.yMinimum(), rect.yMaximum())
-                return True
-        except:
-            pass
-
-        tokens = str(value).split(',')
-        if len(tokens) != 4:
-            return False
-        try:
-            float(tokens[0])
-            float(tokens[1])
-            float(tokens[2])
-            float(tokens[3])
-            self.value = value
-            return True
-        except:
-            return False
-
     def getValueAsCommandLineParameter(self):
         if self.value is not None:
             return '"' + str(self.value) + '"'
@@ -320,32 +213,10 @@ class ParameterExtent(Parameter):
 
 class ParameterPoint(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.PointWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', default=None, optional=False):
         Parameter.__init__(self, name, description, default, optional)
         # The value is a string in the form "x, y"
 
-    def setValue(self, text):
-        if text is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        tokens = str(text).split(',')
-        if len(tokens) != 2:
-            return False
-        try:
-            float(tokens[0])
-            float(tokens[1])
-            self.value = text
-            return True
-        except:
-            return False
-
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"'
 
@@ -367,10 +238,6 @@ class ParameterPoint(Parameter):
 
 class ParameterFile(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.FileWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', isFolder=False, optional=True, ext=None):
         Parameter.__init__(self, name, description, None, parseBool(optional))
         self.ext = ext
@@ -379,18 +246,6 @@ class ParameterFile(Parameter):
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"'
 
-    def setValue(self, obj):
-        if obj is None or obj.strip() == '':
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None if obj is None else obj.strip()
-            return True
-
-        if self.ext is not None and obj != '' and not obj.endswith(self.ext):
-            return False
-        self.value = str(obj)
-        return True
-
     def getAsScriptCode(self):
         param_type = ''
         if self.flags() & QgsProcessingParameterDefinition.FlagOptional:
@@ -420,20 +275,6 @@ class ParameterFixedTable(Parameter):
         self.numRows = int(numRows)
         self.fixedNumOfRows = parseBool(fixedNumOfRows)
 
-    def setValue(self, obj):
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        # TODO: check that it contains a correct number of elements
-        if isinstance(obj, str):
-            self.value = obj
-        else:
-            self.value = ParameterFixedTable.tableToString(obj)
-        return True
-
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"'
 
@@ -469,10 +310,6 @@ class ParameterMultipleInput(ParameterDataObject):
     each of which represents the data source location of each element.
     """
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.MultipleInputWidgetWrapper'
-    }
-
     exported = None
 
     def __init__(self, name='', description='', datatype=-1, optional=False, metadata={}):
@@ -512,31 +349,6 @@ class ParameterMultipleInput(ParameterDataObject):
     def getMinNumInputs(self):
         return self.minNumInputs
 
-    def setValue(self, obj):
-        self.exported = None
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(obj, list):
-            if len(obj) == 0:
-                if self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                    self.value = None
-                    return True
-                else:
-                    return False
-            # prevent setting value if we didn't provide required minimal number of inputs
-            elif len(obj) < self.minNumInputs:
-                return False
-
-            self.value = ";".join([self.getAsString(lay) for lay in obj])
-            return True
-        else:
-            self.value = str(obj)
-            return True
-
     def getSafeExportedLayers(self):
         """
         Returns not the value entered by the user, but a string with
@@ -667,10 +479,6 @@ class ParameterMultipleInput(ParameterDataObject):
 
 class ParameterNumber(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.NumberWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', minValue=None, maxValue=None,
                  default=None, optional=False, metadata={}):
         Parameter.__init__(self, name, description, default, optional, metadata)
@@ -695,39 +503,6 @@ class ParameterNumber(Parameter):
             self.max = None
         self.value = self.default
 
-    def setValue(self, n):
-        if n is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(n, str):
-            try:
-                self.value = float(n)
-                if self.isInteger:
-                    self.value = int(math.floor(self.value))
-                return True
-            except:
-                return False
-        else:
-            try:
-                if float(n) - int(float(n)) == 0:
-                    value = int(float(n))
-                else:
-                    value = float(n)
-                if self.min is not None:
-                    if value < self.min:
-                        return False
-                if self.max is not None:
-                    if value > self.max:
-                        return False
-                self.value = value
-                return True
-            except:
-                raise
-                return False
-
     def getAsScriptCode(self):
         param_type = ''
         if self.flags() & QgsProcessingParameterDefinition.FlagOptional:
@@ -812,34 +587,12 @@ class ParameterRange(Parameter):
         else:
             self.isInteger = False
 
-    def setValue(self, text):
-        if text is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        tokens = text.split(',')
-        if len(tokens) != 2:
-            return False
-        try:
-            float(tokens[0])
-            float(tokens[1])
-            self.value = text
-            return True
-        except:
-            return False
-
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"' if self.value is not None else str(None)
 
 
 class ParameterRaster(ParameterDataObject):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.RasterWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', optional=False, showSublayersDialog=True):
         ParameterDataObject.__init__(self, name, description, None, optional)
         self.showSublayersDialog = parseBool(showSublayersDialog)
@@ -874,21 +627,6 @@ class ParameterRaster(ParameterDataObject):
             self.exported = self.value
         return self.exported
 
-    def setValue(self, obj):
-        self.exported = None
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(obj, QgsRasterLayer):
-            self.value = str(obj.dataProvider().dataSourceUri())
-            return True
-        else:
-            self.value = str(obj)
-            return True
-
     def getFileFilter(self):
         exts = dataobjects.getSupportedOutputRasterLayerExtensions()
         for i in range(len(exts)):
@@ -912,10 +650,6 @@ class ParameterRaster(ParameterDataObject):
 
 class ParameterSelection(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.SelectionWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', options=[], default=None, isSource=False,
                  multiple=False, optional=False):
         Parameter.__init__(self, name, description, default, optional)
@@ -947,47 +681,6 @@ class ParameterSelection(Parameter):
         self.values = [option[0] for option in options]
 
         self.value = None
-        if default is not None:
-            self.setValue(self.defaultValue())
-
-    def setValue(self, value):
-        if value is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(value, list):
-            if not self.multiple:
-                return False
-            values = []
-            for v in value:
-                if v in self.values:
-                    values.append(v)
-                    continue
-                try:
-                    v = int(v)
-                except:
-                    pass
-                if v not in self.values:
-                    return False
-                values.append(v)
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional and len(values) == 0:
-                return False
-            self.value = values
-            return True
-        else:
-            if value in self.values:
-                self.value = value
-                return True
-            try:
-                value = int(value)
-            except:
-                pass
-            if value not in self.values:
-                return False
-            self.value = value
-            return True
 
     @classmethod
     def fromScriptCode(self, line):
@@ -1017,10 +710,6 @@ class ParameterEvaluationException(Exception):
 
 class ParameterString(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.StringWidgetWrapper'
-    }
-
     NEWLINE = '\n'
     ESCAPED_NEWLINE = '\\n'
 
@@ -1029,19 +718,6 @@ class ParameterString(Parameter):
         Parameter.__init__(self, name, description, default, optional, metadata)
         self.multiline = parseBool(multiline)
 
-    def setValue(self, obj):
-        if not bool(obj):
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        self.value = str(obj).replace(
-            ParameterString.ESCAPED_NEWLINE,
-            ParameterString.NEWLINE
-        )
-        return True
-
     def getValueAsCommandLineParameter(self):
         return ('"' + str(self.value.replace(ParameterString.NEWLINE,
                                              ParameterString.ESCAPED_NEWLINE)) + '"'
@@ -1078,10 +754,6 @@ class ParameterString(Parameter):
 
 class ParameterExpression(Parameter):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.ExpressionWidgetWrapper'
-    }
-
     NEWLINE = '\n'
     ESCAPED_NEWLINE = '\\n'
 
@@ -1089,19 +761,6 @@ class ParameterExpression(Parameter):
         Parameter.__init__(self, name, description, default, optional)
         self.parent_layer = parent_layer
 
-    def setValue(self, obj):
-        if not bool(obj):
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        self.value = str(obj).replace(
-            ParameterString.ESCAPED_NEWLINE,
-            ParameterString.NEWLINE
-        )
-        return True
-
     def getValueAsCommandLineParameter(self):
         return ('"' + str(self.value.replace(ParameterExpression.NEWLINE,
                                              ParameterExpression.ESCAPED_NEWLINE)) + '"'
@@ -1130,38 +789,10 @@ class ParameterExpression(Parameter):
 
 class ParameterTable(ParameterDataObject):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.TableWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', optional=False):
         ParameterDataObject.__init__(self, name, description, None, optional)
         self.exported = None
 
-    def setValue(self, obj):
-        self.exported = None
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(obj, QgsVectorLayer):
-            source = str(obj.source())
-            self.value = source
-            return True
-        else:
-            self.value = str(obj)
-            layers = QgsProcessingUtils.compatibleVectorLayers(QgsProject.instance())
-            for layer in layers:
-                if layer.name() == self.value or layer.source() == self.value:
-                    source = str(layer.source())
-                    self.value = source
-                    return True
-            val = str(obj)
-            self.value = val
-            return os.path.exists(self.value)
-
     def getSafeExportedTable(self):
         """Returns not the value entered by the user, but a string with
         a filename which contains the data of this table, but saved in
@@ -1217,10 +848,6 @@ class ParameterTableField(Parameter):
     Its value is a string that represents the name of the field.
     """
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.TableFieldWidgetWrapper'
-    }
-
     DATA_TYPE_NUMBER = 0
     DATA_TYPE_STRING = 1
     DATA_TYPE_DATETIME = 2
@@ -1236,22 +863,6 @@ class ParameterTableField(Parameter):
     def getValueAsCommandLineParameter(self):
         return '"' + str(self.value) + '"' if self.value is not None else str(None)
 
-    def setValue(self, value):
-        if not bool(value):
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(value, list):
-            if not self.multiple and len(value) > 1:
-                return False
-            self.value = ";".join(value)
-            return True
-        else:
-            self.value = str(value)
-        return True
-
     def __str__(self):
         return self.name() + ' <' + self.__module__.split('.')[-1] + ' from ' \
             + self.parent + '>'
@@ -1296,10 +907,6 @@ class ParameterTableField(Parameter):
 
 class ParameterVector(ParameterDataObject):
 
-    default_metadata = {
-        'widget_wrapper': 'processing.gui.wrappers.VectorWidgetWrapper'
-    }
-
     def __init__(self, name='', description='', datatype=[-1],
                  optional=False):
         ParameterDataObject.__init__(self, name, description, None, optional)
@@ -1311,21 +918,6 @@ class ParameterVector(ParameterDataObject):
         self.exported = None
         self.allowOnlyOpenedLayers = False
 
-    def setValue(self, obj):
-        self.exported = None
-        if obj is None:
-            if not self.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                return False
-            self.value = None
-            return True
-
-        if isinstance(obj, QgsVectorLayer):
-            self.value = str(obj.source())
-            return True
-        else:
-            self.value = str(obj)
-            return True
-
     def getSafeExportedLayer(self):
         """Returns not the value entered by the user, but a string with
         a filename which contains the data of this layer, but saved in
diff --git a/python/plugins/processing/modeler/ModelerAlgorithm.py b/python/plugins/processing/modeler/ModelerAlgorithm.py
index d72b04e4ce5..18b55b80d2e 100644
--- a/python/plugins/processing/modeler/ModelerAlgorithm.py
+++ b/python/plugins/processing/modeler/ModelerAlgorithm.py
@@ -424,8 +424,8 @@ class ModelerAlgorithm(GeoAlgorithm):
                     value = param.defaultValue()
                 # We allow unexistent filepaths, since that allows
                 # algorithms to skip some conversion routines
-                if not param.setValue(value) and not isinstance(param,
-                                                                ParameterDataObject):
+                if not param.checkValueIsAcceptable(value) and not isinstance(param,
+                                                                              ParameterDataObject):
                     raise GeoAlgorithmExecutionException(
                         self.tr('Wrong value {0} for {1} {2}', 'ModelerAlgorithm').format(
                             value, param.__class__.__name__, param.name()
diff --git a/python/plugins/processing/preconfigured/PreconfiguredAlgorithm.py b/python/plugins/processing/preconfigured/PreconfiguredAlgorithm.py
index bb54ea5140a..6eef494fb6d 100644
--- a/python/plugins/processing/preconfigured/PreconfiguredAlgorithm.py
+++ b/python/plugins/processing/preconfigured/PreconfiguredAlgorithm.py
@@ -30,6 +30,7 @@ import os
 from qgis.core import (QgsProcessingAlgorithm,
                        QgsApplication)
 from processing.core.GeoAlgorithm import GeoAlgorithm
+from copy import deepcopy
 import json
 
 
@@ -57,10 +58,11 @@ class PreconfiguredAlgorithm(GeoAlgorithm):
         return QgsProcessingAlgorithm.FlagHideFromModeler
 
     def execute(self, parameters, context=None, feedback=None, model=None):
+        new_parameters = deepcopy(parameters)
         self.alg = QgsApplication.processingRegistry().algorithmById(self.description["algname"])
         for name, value in list(self.description["parameters"].items()):
-            self.alg.setParameterValue(name, value)
+            new_parameters[name] = value
         for name, value in list(self.description["outputs"].items()):
             self.alg.setOutputValue(name, value)
-        self.alg.execute(parameters, feedback)
+        self.alg.execute(new_parameters, feedback)
         self.outputs = self.alg.outputs
diff --git a/python/plugins/processing/script/ScriptAlgorithm.py b/python/plugins/processing/script/ScriptAlgorithm.py
index 0d465836c5d..498c263f4b0 100644
--- a/python/plugins/processing/script/ScriptAlgorithm.py
+++ b/python/plugins/processing/script/ScriptAlgorithm.py
@@ -174,8 +174,8 @@ class ScriptAlgorithm(GeoAlgorithm):
         ns['scriptDescriptionFile'] = self.descriptionFile
         ns['context'] = context
 
-        for param in self.parameters:
-            ns[param.name] = param.value
+        for param in self.parameterDefinitions():
+            ns[param.name] = parameters[param.name()]
 
         for out in self.outputs:
             ns[out.name] = out.value
@@ -230,9 +230,9 @@ class ScriptAlgorithm(GeoAlgorithm):
             with open(helpFile) as f:
                 try:
                     descriptions = json.load(f)
-                    for param in self.parameters:
-                        if param.name in descriptions:
-                            descs[param.name] = str(descriptions[param.name])
+                    for param in self.parameterDefinitions():
+                        if param.name() in descriptions:
+                            descs[param.name()] = str(descriptions[param.name()])
                 except:
                     return descs
         return descs
diff --git a/python/plugins/processing/tests/AlgorithmsTestBase.py b/python/plugins/processing/tests/AlgorithmsTestBase.py
index 62e335fd6f0..6d7fa1cfb56 100644
--- a/python/plugins/processing/tests/AlgorithmsTestBase.py
+++ b/python/plugins/processing/tests/AlgorithmsTestBase.py
@@ -105,8 +105,8 @@ class AlgorithmsTest(object):
 
         parameters = {}
         if isinstance(params, list):
-            for param in zip(alg.parameters, params):
-                parameters[param[0].name] = param[1]
+            for param in zip(alg.parameterDefinitions(), params):
+                parameters[param[0].name()] = param[1]
         else:
             for k, p in list(params.items()):
                 parameters[k] = p