Check if app factory takes script_info argument and call it with(out) script_info as an argument depending on that

flask/cli.py

@@ -22,13 +22,14 @@ from . import __version__
 from ._compat import iteritems, reraise
 from .globals import current_app
 from .helpers import get_debug_flag
+from ._compat import getargspec
 
 
 class NoAppException(click.UsageError):
     """Raised if an application cannot be found or loaded."""
 
 
-def find_best_app(module):
+def find_best_app(script_info, module):
     """Given a module instance this tries to find the best possible
     application in the module or raises an exception.
     """
@@ -60,8 +61,8 @@ def find_best_app(module):
 
         if callable(app_factory):
             try:
-                app = app_factory()
-
+                app = check_factory_for_script_info_and_call(app_factory,
+                                                             script_info)
                 if isinstance(app, Flask):
                     return app
             except TypeError:
@@ -79,6 +80,21 @@ def find_best_app(module):
     )
 
 
+def check_factory_for_script_info_and_call(func, script_info):
+    """Given a function this checks if the function has an argument named 
+    script_info or just a single argument and calls the function with 
+    script_info if so. Otherwise calls the function without any arguments and 
+    returns the result."""
+    arguments = getargspec(func).args
+    if 'script_info' in arguments:
+        result = func(script_info=script_info)
+    elif len(arguments) == 1:
+        result = func(script_info)
+    else:
+        result = func()
+    return result
+
+
 def prepare_exec_for_file(filename):
     """Given a filename this will try to calculate the python path, add it
     to the search path and return the actual module name that is expected.
@@ -108,7 +124,7 @@ def prepare_exec_for_file(filename):
     return '.'.join(module[::-1])
 
 
-def locate_app(app_id):
+def locate_app(script_info, app_id):
     """Attempts to locate the application."""
     __traceback_hide__ = True
     if ':' in app_id:
@@ -134,7 +150,7 @@ def locate_app(app_id):
 
     mod = sys.modules[module]
     if app_obj is None:
-        app = find_best_app(mod)
+        app = find_best_app(script_info, mod)
     else:
         app = getattr(mod, app_obj, None)
         if app is None:
@@ -259,7 +275,7 @@ class ScriptInfo(object):
         if self._loaded_app is not None:
             return self._loaded_app
         if self.create_app is not None:
-            rv = self.create_app(self)
+            rv = check_factory_for_script_info_and_call(self.create_app, self)
         else:
             if not self.app_import_path:
                 raise NoAppException(
@@ -267,7 +283,7 @@ class ScriptInfo(object):
                     'the FLASK_APP environment variable.\n\nFor more '
                     'information see '
                     'http://flask.pocoo.org/docs/latest/quickstart/')
-            rv = locate_app(self.app_import_path)
+            rv = locate_app(self, self.app_import_path)
         debug = get_debug_flag()
         if debug is not None:
             rv.debug = debug