Check if plugin as a parser command before adding it into the OrderedList.

Indeed some plugins may not need to define one.

papers/papers_cmd.py

@@ -38,6 +38,7 @@ def execute(raw_args = sys.argv):
     # Extend with plugin commands
     plugins.load_plugins(ui, config.plugins.split())
     for p in plugins.get_plugins().values():
+        if getattr(p, 'parser') and getattr(p, 'command'):
             cmds.update(collections.OrderedDict([(p.name, p)]))
 
     parser = argparse.ArgumentParser(description="research papers repository")

papers/plugins.py

@@ -12,11 +12,10 @@ class PapersPlugin(object):
     functionality by defining a subclass of PapersPlugin and overriding
     the abstract methods defined here.
     """
-    def __init__(self, ui):
+    def __init__(self):
         """Perform one-time plugin setup.
         """
         self.name = self.__module__.split('.')[-1]
-        self.ui = ui
 
     #ui and given again to stay consistent with the core papers cmd.
     #two options:
@@ -25,7 +24,7 @@ class PapersPlugin(object):
     #this may end up with a lot of function with config/ui in argument
     #or just keep it that way...
     def parser(self, subparsers):
-        """ Should retrun the parser with plugins specific command.
+        """ Should return the parser with plugins specific command.
         This is a basic example
         """
         parser = subparsers.add_parser(self.name, help="echo string in argument")
@@ -59,7 +58,7 @@ def load_plugins(ui, names):
     """
     for name in names:
         modname = '%s.%s.%s.%s' % ('papers', PLUGIN_NAMESPACE, name, name)
-        try:
+        #try:
         try:
             namespace = importlib.import_module(modname)
         except ImportError as exc:
@@ -73,10 +72,10 @@ def load_plugins(ui, names):
                 if isinstance(obj, type) and issubclass(obj, PapersPlugin) \
                         and obj != PapersPlugin:
                     _classes.append(obj)
-                        _instances[obj] = obj(ui)
+                    _instances[obj] = obj()
 
-        except:
+        #except:
-            ui.warning('error loading plugin {}'.format(name))
+        #    ui.warning('error loading plugin {}'.format(name))
 
 
 def get_plugins():