From d379573e679d8034335336bc52483060f0eed694 Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Tue, 17 Jan 2017 17:37:41 +0000
Subject: [PATCH 1/3] Added a function to avoid circular calling of methods
 (useful when dealing with callbacks)

---
 glue/utils/decorators.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/glue/utils/decorators.py b/glue/utils/decorators.py
index 86d979e8f..0063f6ab3 100644
--- a/glue/utils/decorators.py
+++ b/glue/utils/decorators.py
@@ -2,7 +2,7 @@
 
 import traceback
 
-__all__ = ['die_on_error']
+__all__ = ['die_on_error', 'avoid_circular']
 
 
 def die_on_error(msg):
@@ -23,3 +23,14 @@ def wrapper(*args, **kwargs):
                 print('=' * 72)
         return wrapper
     return decorator
+
+
+def avoid_circular(meth):
+    def wrapper(self, *args, **kwargs):
+        if not hasattr(self, '_active_callback') or not self._active_callback:
+            self._active_callback = True
+            try:
+                return meth(self, *args, **kwargs)
+            finally:
+                self._active_callback = False
+    return wrapper

From 54d65fde09de864c5533ebe6a3867da88c20c7cf Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Tue, 17 Jan 2017 17:42:42 +0000
Subject: [PATCH 2/3] Added unit test and changelog entry

---
 CHANGES.md                         |  3 +++
 glue/utils/decorators.py           |  6 +++---
 glue/utils/tests/test_decorator.py | 19 +++++++++++++++++++
 3 files changed, 25 insertions(+), 3 deletions(-)
 create mode 100644 glue/utils/tests/test_decorator.py

diff --git a/CHANGES.md b/CHANGES.md
index 31eb47403..185afdc42 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -21,6 +21,9 @@ v0.10.0 (unreleased)
   Finally, ``ComponentID`` objects now hold a reference to the first parent data
   they are used in. [#1189]
 
+- Added a decorator that can be used to avoid circular calling of methods (can
+  occur when dealing with callbacks).
+
 v0.9.2 (unreleased)
 -------------------
 
diff --git a/glue/utils/decorators.py b/glue/utils/decorators.py
index 0063f6ab3..780a796f4 100644
--- a/glue/utils/decorators.py
+++ b/glue/utils/decorators.py
@@ -27,10 +27,10 @@ def wrapper(*args, **kwargs):
 
 def avoid_circular(meth):
     def wrapper(self, *args, **kwargs):
-        if not hasattr(self, '_active_callback') or not self._active_callback:
-            self._active_callback = True
+        if not hasattr(self, '_in_avoid_circular') or not self._in_avoid_circular:
+            self._in_avoid_circular = True
             try:
                 return meth(self, *args, **kwargs)
             finally:
-                self._active_callback = False
+                self._in_avoid_circular = False
     return wrapper
diff --git a/glue/utils/tests/test_decorator.py b/glue/utils/tests/test_decorator.py
new file mode 100644
index 000000000..a009cffab
--- /dev/null
+++ b/glue/utils/tests/test_decorator.py
@@ -0,0 +1,19 @@
+from ..decorators import avoid_circular
+
+
+def test_avoid_circular():
+
+    class CircularCall(object):
+
+        @avoid_circular
+        def a(self):
+            self.b()
+
+        @avoid_circular
+        def b(self):
+            self.a()
+
+    c = CircularCall()
+
+    # Without avoid_circular, the following causes a recursion error
+    c.a()

From 0a0f7f845bc79ce673519280ddc6c4f603b18e6d Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Tue, 17 Jan 2017 18:54:08 +0000
Subject: [PATCH 3/3] Added PR number in changelog [ci skip]

---
 CHANGES.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index 185afdc42..fff8f5bc0 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -22,7 +22,7 @@ v0.10.0 (unreleased)
   they are used in. [#1189]
 
 - Added a decorator that can be used to avoid circular calling of methods (can
-  occur when dealing with callbacks).
+  occur when dealing with callbacks). [#1207]
 
 v0.9.2 (unreleased)
 -------------------