Find module paths using entry points

Closes #12900
(grafted from d9ef251eee77a95b3f0c5be9c6c036790072439f)

--HG--
branch : 7.0

trytond/doc/ref/tools/misc.rst

@@ -4,6 +4,14 @@
 Miscellaneous
 =============
 
+.. function:: entry_points()
+
+   Return a collection of entry points.
+
+.. function:: import_module(name)
+
+   Import the named Tryton module.
+
 .. function:: file_open(name[, mode[, subdir[, encoding]]])
 
    Open the named file in subdir from the root directory.

trytond/trytond/const.py

@@ -20,3 +20,4 @@ OPERATORS = (
     '<',
     '>',
     )
+MODULES_GROUP = 'trytond.modules'

trytond/trytond/modules/__init__.py

@@ -1,24 +1,19 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
 import configparser
-import importlib
 import itertools
 import logging
 import os
 from collections import defaultdict
 from glob import iglob
 
-try:
-    from backports.entry_points_selectable import entry_points
-except ImportError:
-    from importlib.metadata import entry_points
-
 from sql import Table
 from sql.functions import CurrentTimestamp
 
 import trytond.convert as convert
 import trytond.tools as tools
 from trytond.config import config
+from trytond.const import MODULES_GROUP
 from trytond.exceptions import MissingDependenciesException
 from trytond.transaction import Transaction
 
@@ -286,7 +281,7 @@ def get_modules(with_test=False):
                 continue
             if os.path.isdir(OPJ(MODULES_PATH, file)):
                 modules.add(file)
-    for ep in entry_points().select(group='trytond.modules'):
+    for ep in tools.entry_points().select(group=MODULES_GROUP):
         modules.add(ep.name)
     if with_test:
         modules.add('tests')
@@ -313,7 +308,7 @@ def register_classes(with_test=False):
             MODULES.append(module_name)
             continue
 
-        module = importlib.import_module(f'trytond.modules.{module_name}')
+        module = tools.import_module(module_name)
         # Some modules register nothing in the Pool
         if hasattr(module, 'register'):
             module.register()

trytond/trytond/tools/__init__.py

@@ -14,11 +14,12 @@ except ImportError:
 
 from .decimal_ import decistmt
 from .misc import (
-    escape_wildcard, file_open, find_dir, find_path, firstline,
-    get_smtp_server, grouped_slice, is_full_text, is_instance_method, likify,
-    lstrip_wildcard, pairwise_longest, reduce_domain, reduce_ids,
-    remove_forbidden_chars, resolve, rstrip_wildcard, slugify, sortable_values,
-    sql_pairing, strip_wildcard, unescape_wildcard)
+    entry_points, escape_wildcard, file_open, find_dir, find_path, firstline,
+    get_smtp_server, grouped_slice, import_module, is_full_text,
+    is_instance_method, likify, lstrip_wildcard, pairwise_longest,
+    reduce_domain, reduce_ids, remove_forbidden_chars, resolve,
+    rstrip_wildcard, slugify, sortable_values, sql_pairing, strip_wildcard,
+    unescape_wildcard)
 
 
 class ClassProperty(property):
@@ -41,6 +42,7 @@ __all__ = [
     cached_property,
     cursor_dict,
     decistmt,
+    entry_points,
     escape_wildcard,
     file_open,
     find_dir,
@@ -48,6 +50,7 @@ __all__ = [
     firstline,
     get_smtp_server,
     grouped_slice,
+    import_module,
     is_full_text,
     is_instance_method,
     likify,

trytond/trytond/tools/misc.py

@@ -20,7 +20,28 @@ from sql import Literal
 from sql.conditionals import Case
 from sql.operators import Or
 
-from trytond.const import OPERATORS
+from trytond.const import MODULES_GROUP, OPERATORS
+
+try:
+    from backports.entry_points_selectable import entry_points as _entry_points
+except ImportError:
+    from importlib.metadata import entry_points as _entry_points
+_ENTRY_POINTS = None
+
+
+def entry_points():
+    global _ENTRY_POINTS
+    if _ENTRY_POINTS is None:
+        _ENTRY_POINTS = _entry_points()
+    return _ENTRY_POINTS
+
+
+def import_module(name):
+    try:
+        ep, = entry_points().select(group=MODULES_GROUP, name=name)
+    except ValueError:
+        return importlib.import_module(f'{MODULES_GROUP}.{name}')
+    return ep.load()
 
 
 def file_open(name, mode="r", subdir='modules', encoding=None):
@@ -51,8 +72,7 @@ def find_path(name, subdir='modules', _test=os.path.isfile):
                 path = secure_join(root_path, module_name, module_path)
             else:
                 try:
-                    module = importlib.import_module(
-                        f'trytond.modules.{module_name}')
+                    module = import_module(module_name)
                 except ModuleNotFoundError:
                     path = secure_join(root_path, subdir, name)
                 else: