Add mjs_getPluginAttributes.

PiperOrigin-RevId: 752691116
Change-Id: Ib503a99f8d10661b8bf92410ccf471420f924986

python/mujoco/introspect/functions.py

@@ -10298,6 +10298,22 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
          ),
          doc='Get double array contents and optionally its size.',
      )),
+    ('mjs_getPluginAttributes',
+     FunctionDecl(
+         name='mjs_getPluginAttributes',
+         return_type=PointerType(
+             inner_type=ValueType(name='void', is_const=True),
+         ),
+         parameters=(
+             FunctionParameterDecl(
+                 name='plugin',
+                 type=PointerType(
+                     inner_type=ValueType(name='mjsPlugin', is_const=True),
+                 ),
+             ),
+         ),
+         doc='Get plugin attributes.',
+     )),
     ('mjs_setDefault',
      FunctionDecl(
          name='mjs_setDefault',

python/mujoco/specs.cc

@@ -1034,8 +1034,15 @@ PYBIND11_MODULE(_specs, m) {
                 [](raw::MjsPlugin& self) { mjs_delete(self.element); });
   mjsPlugin.def_property(
       "config",
-      [](raw::MjsPlugin& self) -> void {
-        throw pybind11::value_error("Reading plugin config is not supported.");
+      [](raw::MjsPlugin& self) -> py::dict {
+        const std::map<std::string, std::string, std::less<>>* config_attribs =
+            static_cast<const std::map<std::string, std::string, std::less<>>*>(
+                mjs_getPluginAttributes(&self));
+        py::dict config;
+        for (const auto& [key, value] : *config_attribs) {
+          config[py::str(key)] = value;
+        }
+        return config;
       },
       [](raw::MjsPlugin& self, py::dict& config) {
         std::map<std::string, std::string, std::less<>> config_attribs;
@@ -1047,7 +1054,8 @@ PYBIND11_MODULE(_specs, m) {
           config_attribs[key_str] = value.cast<std::string>();
         }
         mjs_setPluginAttributes(&self, &config_attribs);
-      });
+      },
+      py::return_value_policy::reference_internal);
   // ============================= MJVISUAL ====================================
   mjVisual.def_property(
       "global_",

python/mujoco/specs_test.py

@@ -844,6 +844,7 @@ class SpecsTest(absltest.TestCase):
         info='info'
     )
     plugin.config = {'twist': '10', 'bend': '1'}
+    self.assertEqual(plugin.config, {'twist': '10', 'bend': '1'})
 
     body = spec.worldbody.add_body()
     body.plugin = plugin