[Processing] Add optional capabilities to R scripts

python/plugins/processing/algs/r/RAlgorithm.py

@@ -153,84 +153,123 @@ def processParameterLine(self, line):
         if tokens[1].lower().strip() == 'group':
             self.group = tokens[0]
             return
-        if tokens[1].lower().strip().startswith('raster'):
-            param = ParameterRaster(tokens[0], desc, False)
-        elif tokens[1].lower().strip() == 'vector':
-            param = ParameterVector(tokens[0], desc,
+
+        if tokens[1].lower().strip().startswith('output'):
+            outToken = tokens[1].strip()[len('output') + 1:]
+            out = self.processOutputParameterToken(outToken)
+
+        elif tokens[1].lower().strip().startswith('optional'):
+            optToken = tokens[1].strip()[len('optional') + 1:]
+            param = self.processInputParameterToken(optToken, tokens[0])
+            if param:
+                param.optional = True
+
+        else:
+            param = self.processInputParameterToken(tokens[1], tokens[0])
+
+        if param is not None:
+            self.addParameter(param)
+        elif out is not None:
+            out.name = tokens[0]
+            out.description = tokens[0]
+            self.addOutput(out)
+        else:
+            raise WrongScriptException(
+                self.tr('Could not load R script: %s.\n Problem with line %s' % (self.descriptionFile, line)))
+
+    def processInputParameterToken(self, token, name):
+        param = None
+
+        desc = self.createDescriptiveName(name)
+
+        if token.lower().strip().startswith('raster'):
+            param = ParameterRaster(name, desc, False)
+        elif token.lower().strip() == 'vector':
+            param = ParameterVector(name, desc,
                                     [ParameterVector.VECTOR_TYPE_ANY])
-        elif tokens[1].lower().strip() == 'vector point':
-            param = ParameterVector(tokens[0], desc,
+        elif token.lower().strip() == 'vector point':
+            param = ParameterVector(name, desc,
                                     [ParameterVector.VECTOR_TYPE_POINT])
-        elif tokens[1].lower().strip() == 'vector line':
-            param = ParameterVector(tokens[0], desc,
+        elif token.lower().strip() == 'vector line':
+            param = ParameterVector(name, desc,
                                     [ParameterVector.VECTOR_TYPE_LINE])
-        elif tokens[1].lower().strip() == 'vector polygon':
-            param = ParameterVector(tokens[0], desc,
+        elif token.lower().strip() == 'vector polygon':
+            param = ParameterVector(name, desc,
                                     [ParameterVector.VECTOR_TYPE_POLYGON])
-        elif tokens[1].lower().strip() == 'table':
-            param = ParameterTable(tokens[0], desc, False)
-        elif tokens[1].lower().strip().startswith('multiple raster'):
-            param = ParameterMultipleInput(tokens[0], desc,
+        elif token.lower().strip() == 'table':
+            param = ParameterTable(name, desc, False)
+        elif token.lower().strip().startswith('multiple raster'):
+            param = ParameterMultipleInput(name, desc,
                                            ParameterMultipleInput.TYPE_RASTER)
             param.optional = False
-        elif tokens[1].lower().strip() == 'multiple vector':
-            param = ParameterMultipleInput(tokens[0], desc,
+        elif token.lower().strip() == 'multiple vector':
+            param = ParameterMultipleInput(name, desc,
                                            ParameterMultipleInput.TYPE_VECTOR_ANY)
             param.optional = False
-        elif tokens[1].lower().strip().startswith('selection'):
-            options = tokens[1].strip()[len('selection'):].split(';')
-            param = ParameterSelection(tokens[0], desc, options)
-        elif tokens[1].lower().strip().startswith('boolean'):
-            default = tokens[1].strip()[len('boolean') + 1:]
-            param = ParameterBoolean(tokens[0], desc, default)
-        elif tokens[1].lower().strip().startswith('number'):
-            try:
-                default = float(tokens[1].strip()[len('number') + 1:])
-                param = ParameterNumber(tokens[0], desc, default=default)
-            except:
-                raise WrongScriptException(
-                    self.tr('Could not load R script: %s.\n Problem with line %s' % (self.descriptionFile, line)))
-        elif tokens[1].lower().strip().startswith('field'):
-            field = tokens[1].strip()[len('field') + 1:]
+        elif token.lower().strip().startswith('selection'):
+            options = token.strip()[len('selection'):].split(';')
+            param = ParameterSelection(name, desc, options)
+        elif token.lower().strip().startswith('boolean'):
+            default = token.strip()[len('boolean') + 1:]
+            if default:
+                param = ParameterBoolean(name, desc, default)
+            else:
+                param = ParameterBoolean(name, desc)
+        elif token.lower().strip().startswith('number'):
+            default = token.strip()[len('number') + 1:]
+            if default:
+                param = ParameterNumber(name, desc, default=default)
+            else:
+                param = ParameterNumber(name, desc)
+        elif token.lower().strip().startswith('field'):
+            field = token.strip()[len('field') + 1:]
             found = False
             for p in self.parameters:
                 if p.name == field:
                     found = True
                     break
             if found:
-                param = ParameterTableField(tokens[0], tokens[0], field)
-        elif tokens[1].lower().strip() == 'extent':
-            param = ParameterExtent(tokens[0], desc)
-        elif tokens[1].lower().strip() == 'crs':
-            param = ParameterCrs(tokens[0], desc)
-        elif tokens[1].lower().strip() == 'file':
-            param = ParameterFile(tokens[0], desc, False)
-        elif tokens[1].lower().strip() == 'folder':
-            param = ParameterFile(tokens[0], desc, True)
-        elif tokens[1].lower().strip().startswith('string'):
-            default = tokens[1].strip()[len('string') + 1:]
-            param = ParameterString(tokens[0], desc, default)
-        elif tokens[1].lower().strip().startswith('longstring'):
-            default = tokens[1].strip()[len('longstring') + 1:]
-            param = ParameterString(tokens[0], desc, default, multiline=True)
-        elif tokens[1].lower().strip().startswith('output raster'):
+                param = ParameterTableField(name, desc, field)
+        elif token.lower().strip() == 'extent':
+            param = ParameterExtent(name, desc)
+        elif token.lower().strip() == 'file':
+            param = ParameterFile(name, desc, False)
+        elif token.lower().strip() == 'folder':
+            param = ParameterFile(name, desc, True)
+        elif token.lower().strip().startswith('string'):
+            default = token.strip()[len('string') + 1:]
+            if default:
+                param = ParameterString(name, desc, default)
+            else:
+                param = ParameterString(name, desc)
+        elif token.lower().strip().startswith('longstring'):
+            default = token.strip()[len('longstring') + 1:]
+            if default:
+                param = ParameterString(name, desc, default, multiline=True)
+            else:
+                param = ParameterString(name, desc, multiline=True)
+        elif token.lower().strip() == 'crs':
+            default = token.strip()[len('crs') + 1:]
+            if default:
+                param = ParameterCrs(name, desc, default)
+            else:
+                param = ParameterCrs(name, desc)
+
+        return param
+
+    def processOutputParameterToken(self, token):
+        out = None
+
+        if token.lower().strip().startswith('raster'):
             out = OutputRaster()
-        elif tokens[1].lower().strip().startswith('output vector'):
+        elif token.lower().strip().startswith('vector'):
             out = OutputVector()
-        elif tokens[1].lower().strip().startswith('output table'):
+        elif token.lower().strip().startswith('table'):
             out = OutputTable()
-        elif tokens[1].lower().strip().startswith('output file'):
+        elif token.lower().strip().startswith('file'):
             out = OutputFile()
 
-        if param is not None:
-            self.addParameter(param)
-        elif out is not None:
-            out.name = tokens[0]
-            out.description = tokens[0]
-            self.addOutput(out)
-        else:
-            raise WrongScriptException(
-                self.tr('Could not load R script: %s.\n Problem with line %s' % (self.descriptionFile, line)))
+        return out
 
     def processAlgorithm(self, progress):
         if isWindows():