allow link parent to be a str

petercorke · petercorke · commit acdb1b45f6aa · 2021-04-08T12:37:30.000+10:00
move handling to Link class
diff --git a/roboticstoolbox/robot/ELink.py b/roboticstoolbox/robot/ELink.py
@@ -12,16 +12,24 @@
 
 class BaseELink(Link):
 
-    def __init__(self, name=None, joint_name=None):
+    def __init__(self, name=None, parent=None, joint_name=None):
 
         super().__init__()
 
         self._name = name
+
+        if parent is not None:
+            if isinstance(parent, (str, BaseELink)):
+                self._parent = parent
+            else:
+                raise ValueError('parent must be BaseELink subclass or str')
+        else:
+            self._parent = None
+
         self._joint_name = joint_name
 
         self._jindex = None
         self._children = []
-        self._parent = None
 
     def __repr__(self):
         name = self.__class__.__name__
@@ -365,7 +373,6 @@ def __init__(
             ets=ETS(),
             v=None,
             jindex=None,
-            parent=None,
             **kwargs):
 
         # process common options
@@ -385,16 +392,6 @@ def __init__(
             elif jindex is None and v.jindex is not None:
                 jindex = v.jindex
 
-        # TODO simplify this logic, can be ELink class or None
-        # if isinstance(parent, list):
-        #     raise TypeError(
-        #         'Only one parent link can be present')
-        if not isinstance(parent, (ELink, str)) and parent is not None:
-            raise TypeError(
-                'Parent must be of type ELink, str or None')
-
-
-
         # Initialise the static transform representing the constant
         # component of the ETS
         self._init_Ts()
@@ -600,7 +597,6 @@ def __init__(
             ets=ETS2(),
             v=None,
             jindex=None,
-            parent=None,
             **kwargs):
 
         # process common options
@@ -620,14 +616,6 @@ def __init__(
             elif jindex is None and v.jindex is not None:
                 jindex = v.jindex
 
-        # TODO simplify this logic, can be ELink class or None
-        # if isinstance(parent, list):
-        #     raise TypeError(
-        #         'Only one parent link can be present')
-        if not isinstance(parent, (ELink2, str)) and parent is not None:
-            raise TypeError(
-                'Parent must be of type ELink, str or None')
-
         # Initialise the static transform representing the constant
         # component of the ETS
         self._init_Ts()
