Add mjs_getPluginAttributes.

PiperOrigin-RevId: 752691116
Change-Id: Ib503a99f8d10661b8bf92410ccf471420f924986

doc/APIreference/functions.rst

@@ -4401,6 +4401,15 @@ Get string contents.
 
 Get double array contents and optionally its size.
 
+.. _mjs_getPluginAttributes:
+
+`mjs_getPluginAttributes <#mjs_getPluginAttributes>`__
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. mujoco-include:: mjs_getPluginAttributes
+
+Get plugin attributes.
+
 .. _SpecUtilities:
 
 Spec utilities

doc/includes/references.h

@@ -3686,6 +3686,7 @@ void mjs_setDouble(mjDoubleVec* dest, const double* array, int size);
 void mjs_setPluginAttributes(mjsPlugin* plugin, void* attributes);
 const char* mjs_getString(const mjString* source);
 const double* mjs_getDouble(const mjDoubleVec* source, int* size);
+const void* mjs_getPluginAttributes(const mjsPlugin* plugin);
 void mjs_setDefault(mjsElement* element, const mjsDefault* def);
 int mjs_setFrame(mjsElement* dest, mjsFrame* frame);
 const char* mjs_resolveOrientation(double quat[4], mjtByte degree, const char* sequence,

include/mujoco/mujoco.h

@@ -1622,6 +1622,9 @@ MJAPI const char* mjs_getString(const mjString* source);
 // Get double array contents and optionally its size.
 MJAPI const double* mjs_getDouble(const mjDoubleVec* source, int* size);
 
+// Get plugin attributes.
+MJAPI const void* mjs_getPluginAttributes(const mjsPlugin* plugin);
+
 
 //---------------------------------- Spec utilities ------------------------------------------------
 

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

src/user/user_api.cc

@@ -1302,6 +1302,14 @@ void mjs_setPluginAttributes(mjsPlugin* plugin, void* attributes) {
 
 
 
+// get plugin attributes
+const void* mjs_getPluginAttributes(const mjsPlugin* plugin) {
+  mjCPlugin* pluginC = static_cast<mjCPlugin*>(plugin->element);
+  return &pluginC->config_attribs;
+}
+
+
+
 // -------------------------- GLOBAL ASSET CACHE -------------------------------
 
 void mj_setCacheSize(mjCache cache, std::size_t size) {

src/user/user_api.h

@@ -352,6 +352,9 @@ MJAPI const char* mjs_getString(const mjString* source);
 // Get double array contents and optionally its size.
 MJAPI const double* mjs_getDouble(const mjDoubleVec* source, int* size);
 
+// Get plugin attributes.
+MJAPI const void* mjs_getPluginAttributes(const mjsPlugin* plugin);
+
 
 //---------------------------------- Other utilities -----------------------------------------------