Resolved issue "working outside of application context" #220.

Author: losintikfos

flask_mongoengine/__init__.py

@@ -54,7 +54,7 @@ def _patch_base_field(obj, name):
     @param obj:     The object whose footprint to locate the class.
     @param name:    Name of the class to locate.
     """
-    
+
     # locate class
     cls = getattr(obj, name)
     if not inspect.isclass(cls):
@@ -111,6 +111,10 @@ def __init__(self, app=None, config=None):
             self.init_app(app, config)
 
     def init_app(self, app, config=None):
+        from flask import Flask
+        if not app or not isinstance(app, Flask):
+            raise Exception('Invalid Flask application instance')
+
         app.extensions = getattr(app, 'extensions', {})
 
         # Make documents JSON serializable
@@ -131,7 +135,7 @@ def init_app(self, app, config=None):
             config = app.config
 
         # Obtain db connection
-        connection = create_connection(config)
+        connection = create_connection(config, app)
 
         # Store objects in application instance
         # so that multiple apps do not end up

flask_mongoengine/connection.py

@@ -19,6 +19,7 @@
 _tmpdir = None
 _conn = None
 _process = None
+_app_instance = current_app
 
 class InvalidSettingsError(Exception):
     pass
@@ -97,9 +98,9 @@ def get_connection(alias=DEFAULT_CONNECTION_NAME, reconnect=False):
         conn_settings.pop('password', None)
         conn_settings.pop('authentication_source', None)
 
-        is_test = current_app.config.get('TESTING', False)
-        temp_db = current_app.config.get('TEMP_DB', False)
-        preserved = current_app.config.get('PRESERVE_TEMP_DB', False)
+        is_test = _app_instance.config.get('TESTING', False)
+        temp_db = _app_instance.config.get('TEMP_DB', False)
+        preserved = _app_instance.config.get('PRESERVE_TEMP_DB', False)
 
         # Validation
         _validate_settings(is_test, temp_db, preserved, conn_host)
@@ -313,7 +314,7 @@ def fetch_connection_settings(config, removePass=True):
         # Connection settings provided in standard format.
         return _resolve_settings(config, removePass)
 
-def create_connection(config):
+def create_connection(config, app):
     """
     Connection is created based on application configuration
     setting. Application settings which is enabled as TESTING
@@ -346,9 +347,10 @@ def create_connection(config):
         >> app.config['TEMP_DB_LOC'] = '/path/to/temp_dir/'
 
     @param config: Flask-MongoEngine application configuration.
-
+    @param app: instance of flask.Flask
     """
-    global _connection_settings
+    global _connection_settings, _app_instance
+    _app_instance = app
 
     if config is None or not isinstance(config, dict):
         raise Exception("Invalid application configuration");