Small update for pydrivers: force reloading the pydrivers.py Blender

text module when user edits the input text box of any pydriver
(Transform Properties panel, Ipo window).

It's enough to click in and out of a single pydriver's text input box
for the module reloading and also re-evaluation of all pydrivers
available. Maybe this "refreshing" should also be available from a
menu, let's see.

Note for Python fans:

Definitions and redefinitions in a reloaded module are properly handled
in Python, but previously defined data in the module doesn't disappear.
So if you define a function "f" inside a module, import it, then change
the function's name to "g" and reload the module, both "f" and "g" will
be available. This is considered a feature, check reload's documentation:
http://docs.python.org/lib/built-in-funcs.html#l2h-59

2 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/python/BPY_extern.h b/source/blender/python/BPY_extern.h
index cc187ea3a0d..b2c6287f9b3 100644
--- a/source/blender/python/BPY_extern.h
+++ b/source/blender/python/BPY_extern.h
@@ -81,6 +81,7 @@ extern "C" {
 	int BPY_do_spacehandlers(struct ScrArea *sa, unsigned short event,
 		unsigned short space_event);
 
+	void BPY_pydriver_update(void);
 	float BPY_pydriver_eval(struct IpoDriver *driver);
 	struct Object **BPY_pydriver_get_objects(struct IpoDriver *driver);
 
diff --git a/source/blender/python/BPY_interface.c b/source/blender/python/BPY_interface.c
index 6a79e673345..80c4df81bd4 100644
--- a/source/blender/python/BPY_interface.c
+++ b/source/blender/python/BPY_interface.c
@@ -1021,6 +1021,7 @@ static float pydriver_error(IpoDriver *driver) {
 		bpy_pydriver_freeList();
 
 	if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */
+		PyDict_Clear(bpy_pydriver_Dict);
 		Py_DECREF(bpy_pydriver_Dict);
 		bpy_pydriver_Dict = NULL;
 	}
@@ -1034,6 +1035,21 @@ static float pydriver_error(IpoDriver *driver) {
 	return 0.0f;
 }
 
+/* Update function, it gets rid of pydrivers global dictionary, forcing
+ * BPY_pydriver_eval to recreate it. This function is used to force
+ * reloading the Blender text module "pydrivers.py", if available, so
+ * updates in it reach pydriver evaluation. */
+void BPY_pydriver_update(void)
+{
+	if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */
+		PyDict_Clear(bpy_pydriver_Dict);
+		Py_DECREF(bpy_pydriver_Dict);
+		bpy_pydriver_Dict = NULL;
+	}
+
+	return;
+}
+
 /* for depsgraph.c, runs py expr once to collect all refs. made
  * to objects (self refs. to the object that owns the py driver
  * are not allowed). */