add enable_app_replacement param in app_manager (#26)

This allows for both behaviors (replace currently running app or error out) and let's users choose without changing code...
PR2 · Oct 15, 2020 · 4f30de2 · 4f30de2
1 parent 7ef72d3
commit 4f30de2
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/scripts/app_manager b/scripts/app_manager
@@ -91,8 +91,11 @@ def main():
             rospy.logerr("Failed to load exchange: {}".format(e))
             sys.exit(1)
 
+    enable_app_replacement = rospy.get_param('~enable_app_replacement', True)
+
     am = app_manager.AppManager(
-        robot_name, interface_master, app_list, exchange, plugins)
+        robot_name, interface_master, app_list, exchange, plugins,
+        enable_app_replacement=enable_app_replacement)
 
     rospy.on_shutdown(am.shutdown)
 

diff --git a/src/app_manager/app_manager.py b/src/app_manager/app_manager.py
@@ -119,14 +119,15 @@ class AppManager(object):
 
     def __init__(
             self, robot_name, interface_master, app_list,
-            exchange, plugins=None
+            exchange, plugins=None, enable_app_replacement=True,
     ):
         self._robot_name = robot_name
         self._interface_master = interface_master
         self._app_list = app_list
         self._current_app = self._current_app_definition = None
         self._exchange = exchange
         self._plugins = plugins
+        self._enable_app_replacement = enable_app_replacement
 
         rospy.loginfo("Starting app manager for %s"%self._robot_name)
 
@@ -263,9 +264,15 @@ def handle_start_app(self, req):
         if self._current_app:
             if self._current_app_definition.name == req.name:
                 return StartAppResponse(started=True, message="app [%s] already started"%(req.name), namespace=self._app_interface)
+            elif not self._enable_app_replacement:
+                return StartAppResponse(
+                    started=False,
+                    message="app [%s] is denied because app [%s] is already running."
+                            % (req.name, self._current_app_definition.name),
+                    namespace=self._app_interface,
+                    error_code=StatusCodes.MULTIAPP_NOT_SUPPORTED)
             else:
                 self.stop_app(self._current_app_definition.name)
-            #return StartAppResponse(started=False, message="Please stop the running app before starting another app.", error_code=StatusCodes.MULTIAPP_NOT_SUPPORTED)
 
         # TODO: the app list has already loaded the App data.  We should use that instead for consistency