Merged in fix-bodyModel-precedence (pull request #138)

[NRRPLT-7911] The SDF file in a BIBI bodyModel tag has precedence over the SDF of a template model.

Approved-by: erdisayar
Approved-by: Vahid Zolfaghari

hbp_nrp_cleserver/hbp_nrp_cleserver/server/GazeboSimulationAssembly.py

@@ -168,29 +168,27 @@ class GazeboSimulationAssembly(SimulationAssembly):     # pragma: no cover
         For each robot model in sim_config checks that the model sdf file exists in SDFFileAbsPath
         :return: -
         """
-
-        # TODO: the logic implemented here is unnecessarily complex. The model sdf file should
-        #  exists at SDFFileAbsPath as set in bibi file or fail. Differences in custom and public
-        #  models behavior is also weird. Eg. 'model' attribute is ignored for public models and
-        #  'SDFFileAbsPath' ignored for custom models. Not a nice solution.
-
-        # pylint: disable=too-many-branches
         if not self.sim_config.robot_models:
             return
-
         for robot in self.sim_config.robot_models.values():
             robot_handler = RobotCallHandler(self)
-            if robot.model:
-                status, ret = robot_handler.prepare_robot(robot.model)
-                if not status:
-                    raise Exception("Could not prepare custom robot {err}".format(err=ret))
-                sdf_abs_path = ret
-            else: # model files are inside the experiment folder
+
             sdf_abs_path = SimUtil.find_file_in_paths(
                 robot.SDFFileAbsPath,
                 [os.path.join(self.sim_dir, robot.id)]
             )
 
+            # By default, model assets are assumed to be in the experiment folder.
+            # If the model attribute of bodyModel is specified,
+            # assets must be fetched from the template Models instead.
+            if robot.model:
+                status, ret = robot_handler.prepare_robot(robot.model)
+                if not status:
+                    raise Exception("Could not prepare custom robot {err}".format(err=ret))
+                # if no SDF is specified in the BIBI's bodyModel tag
+                # use the SDF of the fetched model
+                sdf_abs_path = ret if not robot.SDFFileAbsPath else sdf_abs_path
+
             # still couldn't find the SDF, abort!
             if not sdf_abs_path:
                 raise Exception("Could not find robot file: {0}".format(robot.SDFFileAbsPath))