fix eager for register function with params=None

.vscode/settings.json

@@ -1,4 +1,6 @@
 {
-    "python.pythonPath": "/home/ian/anaconda3/envs/mpl-inter/bin/python",
-    "python.formatting.provider": "black"
+    "python.formatting.provider": "black",
+    "python.languageServer": "Pylance",
+    "python.linting.enabled": false,
+    "python.analysis.completeFunctionParens": true
 }

mpl_interactions/_version.py

@@ -1,2 +1,2 @@
-version_info = (0, 17, 6)
+version_info = (0, 17, 7)
 __version__ = ".".join(map(str, version_info))

mpl_interactions/controller.py

@@ -191,16 +191,21 @@ def register_callback(self, callback, params=None, eager=False):
         Parameters
         ----------
         callback : callable
-            a function called
-        params : list of str, str, or None
-            the params to be passed to the callback
-        eager : bool
-            Whether to call the callback immediately upon registration
+            A function called. Should accept all of the parameters specified by *params*
+            as a kwargs.
+        params : str, list of str, or None
+            The params to be passed to the callback. If *None* then all params
+            currently registered with this controls object will be used.
+        eager : bool, default: False
+            If True, call the callback immediately upon registration
         """
         if isinstance(params, str):
             params = [params]
         if eager:
-            callback(**{key: self.params[key] for key in params})
+            if params is None:
+                callback(**self.params)
+            else:
+                callback(**{key: self.params[key] for key in params})
         self._register_function(callback, fig=None, params=params)
 
     def _register_function(self, f, fig=None, params=None):

mpl_interactions/tests/test_controls.py

@@ -0,0 +1,16 @@
+from mpl_interactions.controller import Controls
+
+
+def test_eager_register():
+    zoop = []
+
+    def cb(**kwargs):
+        zoop.append(1)
+
+    ctrls = Controls(beep=(0, 1), boop=(0, 1))
+    ctrls.register_callback(cb, None, eager=True)
+    assert len(zoop) == 1
+
+    ctrls = Controls(beep=(0, 1), boop=(0, 1))
+    ctrls.register_callback(cb, "beep", eager=True)
+    assert len(zoop) == 1