Allow configuration options to be overridden by commandline flags.

When obtaining a configuration object, it is now possible to pass
certain values to be overridden no matter what settings were made in the
configuration files.

This is used to let the -t and -d flags (location of todo.txt and
archive respectively) override anything that is mentioned in
configuration files.

This fixes a bug where the edit subcommand did not respect the -t flag,
because it was simply reading the location from the configuration file.
Now the configuration is overridden when -t is passed.

Thanks to Jacek for reporting the broken 'edit' command.

test/ConfigTest.py

@@ -29,5 +29,13 @@ class ConfigTest(TopydoTest):
     def test_config3(self):
         self.assertTrue(config("test/data/config2").ignore_weekends())
 
+    def test_config4(self):
+        """ Test that value in file is overridden by parameter. """
+        overrides = {
+            ('topydo', 'default_command'): 'edit'
+        }
+
+        self.assertEqual(config("test/data/config1", p_overrides=overrides).default_command(), 'edit')
+
 if __name__ == '__main__':
     unittest.main()

topydo/cli/CLI.py

@@ -45,7 +45,7 @@ class CLIApplication(CLIApplicationBase):
         """ Main entry function. """
         args = self._process_flags()
 
-        self.todofile = TodoFile.TodoFile(self.path)
+        self.todofile = TodoFile.TodoFile(config().todotxt())
         self.todolist = TodoList.TodoList(self.todofile.read())
 
         (subcommand, args) = get_subcommand(args)

topydo/cli/CLIApplicationBase.py

@@ -112,11 +112,6 @@ class CLIApplicationBase(object):
     """
     def __init__(self):
         self.todolist = TodoList.TodoList([])
-
-        self.config = config()
-        self.path = self.config.todotxt()
-        self.archive_path = self.config.archive()
-
         self.todofile = None
 
     def _usage(self):
@@ -135,24 +130,25 @@ class CLIApplicationBase(object):
             error(str(e))
             sys.exit(1)
 
-        alt_path = None
-        alt_archive = None
+        alt_config_path = None
+        overrides = {}
 
         for opt, value in opts:
             if opt == "-c":
-                self.config = config(value)
+                alt_config_path = value
             elif opt == "-t":
-                alt_path = value
+                overrides[('topydo', 'filename')] = value
             elif opt == "-d":
-                alt_archive = value
+                overrides[('topydo', 'archive_filename')] = value
             elif opt == "-v":
                 version()
             else:
                 self._usage()
 
-        self.path = alt_path if alt_path else self.config.todotxt()
-        self.archive_path = alt_archive \
-            if alt_archive else self.config.archive()
+        if alt_config_path:
+            config(alt_config_path, overrides)
+        elif len(overrides):
+            config(p_overrides=overrides)
 
         return args
 
@@ -163,7 +159,7 @@ class CLIApplicationBase(object):
         This means that all completed tasks are moved to the archive file
         (defaults to done.txt).
         """
-        archive_file = TodoFile.TodoFile(self.archive_path)
+        archive_file = TodoFile.TodoFile(config().archive())
         archive = TodoListBase.TodoListBase(archive_file.read())
 
         if archive:

topydo/cli/Prompt.py

@@ -51,7 +51,7 @@ class PromptApplication(CLIApplicationBase):
         """ Main entry function. """
         args = self._process_flags()
 
-        self.todofile = TodoFile.TodoFile(self.path)
+        self.todofile = TodoFile.TodoFile(config().todotxt())
         self.todolist = TodoList.TodoList(self.todofile.read())
 
         # suppress upstream issue with Python 2.7

topydo/lib/Config.py

@@ -26,12 +26,17 @@ class ConfigError(Exception):
         return self.text
 
 class _Config:
-    def __init__(self, p_path=None):
+    def __init__(self, p_path=None, p_overrides=None):
         """
         Constructor.
 
         If p_path is given, that is the only configuration file that will be
         read.
+
+        If p_overrides is given, some options are ultimately overridden. This
+        is for some command line options which override any configuration file
+        (such as todo.txt location passed with -t). The key is a tuple of
+        (section, option), the value is the option's value.
         """
         self.sections = ['topydo', 'tags', 'sort', 'ls', 'dep']
 
@@ -84,6 +89,10 @@ class _Config:
 
         self._supplement_sections()
 
+        if p_overrides:
+            for (section, option), value in p_overrides.items():
+                self.cp.set(section, option, value)
+
     def _supplement_sections(self):
         for section in self.sections:
             if not self.cp.has_section(section):
@@ -177,17 +186,21 @@ class _Config:
         hidden_tags = self.cp.get('ls', 'hide_tags')
         return [] if hidden_tags == '' else hidden_tags.split(',')
 
-def config(p_path=None):
+def config(p_path=None, p_overrides=None):
     """
     Retrieve the config instance.
 
     If a path is given, the instance is overwritten by the one that supplies an
     additional filename (for testability). Moreover, no other configuration
     files will be read when a path is given.
+
+    Overrides will discard a setting in any configuration file and use the
+    passed value instead. Structure: (section, option) => value
+    The previous configuration instance will be discarded.
     """
-    if not config.instance or p_path != None:
+    if not config.instance or p_path != None or p_overrides != None:
         try:
-            config.instance = _Config(p_path)
+            config.instance = _Config(p_path, p_overrides)
         except configparser.ParsingError as perr:
             raise ConfigError(str(perr))