fix: guards for template specialization of pyobject fromJson()

Author: shaur-k

CMakeLists.txt

@@ -192,6 +192,7 @@ target_link_libraries(${BTCPP_LIBRARY}
 if(BTCPP_PYTHON)
     find_package(Python COMPONENTS Interpreter Development)
     find_package(pybind11 CONFIG)
+    message("PYTHON_EXECUTABLE: ${Python_EXECUTABLE}")
 
     pybind11_add_module(btpy_cpp src/python/bindings.cpp)
     target_compile_options(btpy_cpp PRIVATE -Wno-gnu-zero-variadic-macro-arguments)

include/behaviortree_cpp/json_export.h

@@ -2,10 +2,15 @@
 
 #include "behaviortree_cpp/utils/safe_any.hpp"
 #include "behaviortree_cpp/basic_types.h"
-
 // Use the version nlohmann::json embedded in BT.CPP
 #include "behaviortree_cpp/contrib/json.hpp"
 
+#ifdef BTCPP_PYTHON
+#include <pybind11/pybind11.h>
+#include <pybind11/pytypes.h>
+#include "behaviortree_cpp/contrib/pybind11_json.hpp"
+#endif
+
 namespace BT
 {
 
@@ -88,7 +93,6 @@ class JsonExporter
     dst = *fromJson<T>(src);
   }
 
-
   /**
    * @brief Register new JSON converters with addConverter<Foo>().
    * You should used first the macro BT_JSON_CONVERTER.
@@ -126,7 +130,14 @@ class JsonExporter
   std::unordered_map<std::type_index, FromJonConverter> from_json_array_converters_;
   std::unordered_map<std::string, BT::TypeInfo> type_names_;
 };
-
+#ifdef BTCPP_PYTHON
+template <>
+inline Expected<pybind11::object>
+JsonExporter::fromJson(const nlohmann::json& source) const
+{
+  return pyjson::from_json(source);
+}
+#endif
 template <typename T>
 inline Expected<T> JsonExporter::fromJson(const nlohmann::json& source) const
 {

python_examples/ex01_sample.py

@@ -4,6 +4,8 @@
 Demo adapted from [btcpp_sample](https://github.com/BehaviorTree/btcpp_sample).
 """
 
+import sys
+sys.path.append('/home/shaurk/git/moveit_pro/dependencies/BehaviorTree.CPP/build')
 from btpy import BehaviorTreeFactory, SyncActionNode, NodeStatus, ports