UserPlugins can't define Parameters

terrapower · Nov 17, 2022 · d3f8a2c · d3f8a2c
1 parent 36fe1bc
commit d3f8a2c
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 1 deletion.
diff --git a/armi/plugins.py b/armi/plugins.py
@@ -639,6 +639,9 @@ def __enforceLimitations(self):
         corral their side effects during a run.
         """
         if issubclass(self.__class__, UserPlugin):
+            assert (
+                len(self.__class__.defineParameters()) == 0
+            ), "UserPlugins cannot define parameters, consider using an ArmiPlugin."
             assert (
                 len(self.__class__.defineParameterRenames()) == 0
             ), "UserPlugins cannot define parameter renames, consider using an ArmiPlugin."
@@ -651,6 +654,23 @@ def __enforceLimitations(self):
             self.defineSettings = lambda: []
             self.defineSettingsValidators = lambda: []
 
+    @staticmethod
+    @HOOKSPEC
+    def defineParameters():
+        """
+        Prevents defining additional parameters.
+
+        .. warning:: This is not overridable.
+
+        Notes
+        -----
+        It is a designed limitation of user plugins that they not define parameters.
+        Parameters are defined when the App() is read in, which is LONG before the settings
+        file has been read. So the parameters are defined before we discover the user plugin.
+        If this is a feature you need, just use an ArmiPlugin.
+        """
+        return {}
+
     @staticmethod
     @HOOKSPEC
     def defineParameterRenames():
@@ -662,7 +682,9 @@ def defineParameterRenames():
         Notes
         -----
         It is a designed limitation of user plugins that they not generate parameter renames,
-        so that they are able to be added to the plugin stack during run time.
+        Parameters are defined when the App() is read in, which is LONG before the settings
+        file has been read. So the parameters are defined before we discover the user plugin.
+        If this is a feature you need, just use a normal Plugin.
         """
         return {}
 

diff --git a/doc/tutorials/making_your_first_app.rst b/doc/tutorials/making_your_first_app.rst
@@ -410,6 +410,7 @@ In most ways, ``UserPluginExample`` above is just a normal
 :py:class:`UserPlugin <armi.plugins.UserPlugin>` class is more limited than a
 regular plugin though, you cannot implement:
 
+* :py:meth:`armi.plugins.ArmiPlugin.defineParameters`
 * :py:meth:`armi.plugins.ArmiPlugin.defineParameterRenames`
 * :py:meth:`armi.plugins.ArmiPlugin.defineSettings`
 * :py:meth:`armi.plugins.ArmiPlugin.defineSettingsValidators`