Rigify: refactor feature sets to avoid modifying global path.

Instead of adding the feature set installation directory
to the global path, and thus inserting the modules into
the top level namespace, add an empty rigify.feature_sets
package and use __path__ to redirect the module loader
to read its sub-modules from the feature set directory.

Now feature set modules are effectively installed into
that package and loaded as 'rigify.feature_sets.foo'.

As an aside, clean up loading code to avoid weird path
manipulations, add more safety checks when installing sets,
and add a way for sets to expose a user-friendly name.

1 files changed, 31 insertions, 34 deletions

diff --git a/rigify/metarig_menu.py b/rigify/metarig_menu.py
index 2c8adac7..dc583a67 100644
--- a/rigify/metarig_menu.py
+++ b/rigify/metarig_menu.py
@@ -22,10 +22,12 @@ import os
 import traceback
 
 from string import capwords
+from collections import defaultdict
 
 import bpy
 
 from . import utils
+from . import feature_set_list
 
 
 class ArmatureSubMenu(bpy.types.Menu):
@@ -39,22 +41,22 @@ class ArmatureSubMenu(bpy.types.Menu):
             layout.operator(op, icon='OUTLINER_OB_ARMATURE', text=text)
 
 
-def get_metarigs(base_path, path, depth=0):
+def get_metarigs(metarigs, base_dir, base_path, *, path=[], nested=False):
     """ Searches for metarig modules, and returns a list of the
         imported modules.
     """
 
-    metarigs = {}
+    dir_path = os.path.join(base_dir, *path)
 
     try:
-        files = os.listdir(os.path.join(base_path, path))
+        files = os.listdir(dir_path)
     except FileNotFoundError:
         files = []
 
     files.sort()
 
     for f in files:
-        is_dir = os.path.isdir(os.path.join(base_path, path, f))  # Whether the file is a directory
+        is_dir = os.path.isdir(os.path.join(dir_path, f))  # Whether the file is a directory
 
         # Stop cases
         if f[0] in [".", "_"]:
@@ -64,19 +66,15 @@ def get_metarigs(base_path, path, depth=0):
             continue
 
         if is_dir:  # Check directories
-            # Check for sub-metarigs
-            metarigs[f] = get_metarigs(base_path, os.path.join(path, f, ""), depth=1)  # "" adds a final slash
+            get_metarigs(metarigs[f], base_dir, base_path, path=[*path, f], nested=True)  # "" adds a final slash
         elif f.endswith(".py"):
             # Check straight-up python files
             f = f[:-3]
-            module_name = os.path.join(path, f).replace(os.sep, ".")
-            metarig_module = utils.get_resource(module_name, base_path=base_path)
-            if depth == 1:
-                metarigs[f] = metarig_module
+            module = utils.get_resource('.'.join([*base_path, *path, f]))
+            if nested:
+                metarigs[f] = module
             else:
-                metarigs[utils.METARIG_DIR] = {f: metarig_module}
-
-    return metarigs
+                metarigs[utils.METARIG_DIR][f] = module
 
 
 def make_metarig_add_execute(m):
@@ -119,11 +117,15 @@ def make_submenu_func(bl_idname, text):
 
 # Get the metarig modules
 def get_internal_metarigs():
-    MODULE_DIR = os.path.dirname(os.path.dirname(__file__))
+    BASE_RIGIFY_DIR = os.path.dirname(__file__)
+    BASE_RIGIFY_PATH = __name__.split('.')[:-1]
+
+    get_metarigs(metarigs, os.path.join(BASE_RIGIFY_DIR, utils.METARIG_DIR), [*BASE_RIGIFY_PATH, utils.METARIG_DIR])
 
-    metarigs.update(get_metarigs(MODULE_DIR, os.path.join(os.path.basename(os.path.dirname(__file__)), utils.METARIG_DIR, '')))
+def infinite_defaultdict():
+    return defaultdict(infinite_defaultdict)
 
-metarigs = {}
+metarigs = infinite_defaultdict()
 metarig_ops = {}
 armature_submenus = []
 menu_funcs = []
@@ -212,29 +214,24 @@ def unregister():
     for mf in menu_funcs:
         bpy.types.VIEW3D_MT_armature_add.remove(mf)
 
-def get_external_metarigs(feature_sets_path):
+def get_external_metarigs(set_list):
     unregister()
 
     # Clear and fill metarigs public variables
     metarigs.clear()
     get_internal_metarigs()
-    metarigs['external'] = {}
-
-    for feature_set in os.listdir(feature_sets_path):
-        if feature_set:
-            try:
-                try:
-                    utils.get_resource(os.path.join(feature_set, '__init__'), feature_sets_path)
-                except FileNotFoundError:
-                    print("Rigify Error: Could not load feature set '%s': __init__.py not found.\n" % (feature_set))
-                    continue
-
-                metarigs['external'].update(get_metarigs(feature_sets_path, os.path.join(feature_set, utils.METARIG_DIR)))
-            except Exception:
-                print("Rigify Error: Could not load feature set '%s' metarigs: exception occurred.\n" % (feature_set))
-                traceback.print_exc()
-                print("")
-                continue
+
+
+    for feature_set in set_list:
+        try:
+            base_dir, base_path = feature_set_list.get_dir_path(feature_set, utils.METARIG_DIR)
+
+            get_metarigs(metarigs['external'], base_dir, base_path)
+        except Exception:
+            print("Rigify Error: Could not load feature set '%s' metarigs: exception occurred.\n" % (feature_set))
+            traceback.print_exc()
+            print("")
+            continue
 
     metarig_ops.clear()
     armature_submenus.clear()