Add suppress_required attribute to the Flag object

pygrass: Add a new method to check the correctness of the provide parameter, a new special parameter: check_ is added to skip the check
         (merge https://trac.osgeo.org/grass/changeset/65596, https://trac.osgeo.org/grass/changeset/65598 from trunk)


git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@65605 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/python/pygrass/modules/interface/flag.py

@@ -33,6 +33,7 @@ class Flag(object):
         self.description = diz.get('description', None)
         self.default = diz.get('default', None)
         self.guisection = diz.get('guisection', None)
+        self.suppress_required = True if 'suppress_required' in diz else False
 
     def get_bash(self):
         """Return the BASH representation of a flag.
@@ -88,11 +89,18 @@ class Flag(object):
         """Return a string with the python representation of the instance."""
         return "Flag <%s> (%s)" % (self.name, self.description)
 
+    def __bool__(self):
+        """Return a boolean value"""
+        return self.value
+
+    def __nonzero__(self):
+        return self.__bool__()
+
     @docstring_property(__doc__)
     def __doc__(self):
         """Return a documentation string, something like:
 
-        {name}: {default}
+        {name}: {default}, suppress required {supress}
             {description}
 
         >>>  flag = Flag(diz=dict(name='a', description='Flag description',
@@ -109,4 +117,7 @@ class Flag(object):
         """
         return read.DOC['flag'].format(name=self.name,
                                        default=repr(self.default),
-                                       description=self.description)
+                                       description=self.description,
+                                       supress=('suppress required'
+                                                if self.suppress_required
+                                                else ''))

lib/python/pygrass/modules/interface/module.py

@@ -504,6 +504,7 @@ class Module(object):
         #
         self.run_ = True
         self.finish_ = True
+        self.check_ = True
         self.env_ = None
         self.stdin_ = None
         self.stdin = None
@@ -543,7 +544,7 @@ class Module(object):
             del(kargs['flags'])
 
         # set attributs
-        for key in ('run_', 'env_', 'finish_', 'stdout_', 'stderr_'):
+        for key in ('run_', 'env_', 'finish_', 'stdout_', 'stderr_', 'check_'):
             if key in kargs:
                 setattr(self, key, kargs.pop(key))
 
@@ -553,7 +554,7 @@ class Module(object):
                 self.inputs[key[:-1]].value = kargs.pop(key)
 
         #
-        # check args
+        # set/update args
         #
         for param, arg in zip(self.params_list, args):
             param.value = arg
@@ -576,11 +577,8 @@ class Module(object):
             #
             # check reqire parameters
             #
-            for k in self.required:
-                if ((k in self.inputs and self.inputs[k].value is None) or
-                        (k in self.outputs and self.outputs[k].value is None)):
-                    msg = "Required parameter <%s> not set."
-                    raise ParameterError(msg % k)
+            if self.check_:
+                self.check()
             return self.run()
         return self
 
@@ -634,6 +632,19 @@ class Module(object):
         flags = self.flags.__doc__
         return '\n'.join([head, params, DOC['flag_head'], flags, DOC['foot']])
 
+    def check(self):
+        """Check the correctness of the provide parameters"""
+        required = True
+        for flg in self.flags.values():
+            if flg and flg.suppress_required:
+                required = False
+        if required:
+            for k in self.required:
+                if ((k in self.inputs and self.inputs[k].value is None) or
+                        (k in self.outputs and self.outputs[k].value is None)):
+                    msg = "Required parameter <%s> not set."
+                    raise ParameterError(msg % k)
+
     def get_dict(self):
         """Return a dictionary that includes the name, all valid
         inputs, outputs and flags

lib/python/pygrass/modules/interface/read.py

@@ -91,7 +91,7 @@ Flags
 """,
     #------------------------------------------------------------
     # flag
-    'flag': """{name}: {default}
+    'flag': """{name}: {default}, {supress}
     {description}""",
     #------------------------------------------------------------
     # foot