fix: guards for template specialization of pyobject fromJson()

Author: shaur-k

CMakeLists.txt

@@ -193,6 +193,7 @@ 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/contrib/pybind11_json.hpp

@@ -9,6 +9,8 @@
 #ifndef PYBIND11_JSON_HPP
 #define PYBIND11_JSON_HPP
 
+#include <pybind11/pytypes.h>
+#include <pybind11/numpy.h>
 #include <string>
 #include <vector>
 
@@ -134,6 +136,10 @@ namespace pyjson
             }
             return out;
         }
+        if (py::isinstance<py::array>(obj))
+        {
+            return obj.cast<nl::json::array_t>();
+        }
         throw std::runtime_error("to_json not implemented for this type of object: " + py::repr(obj).cast<std::string>());
     }
 }

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
 {
 
@@ -82,14 +87,11 @@ class JsonExporter
   template <typename T>
   Expected<T> fromJson(const nlohmann::json& source) const;
 
-  template <typename T>
-  void fromJsonHelper(const nlohmann::json& src, T& dst) const
-  {
-    dst = *fromJson<T>(src);
-  }
-
-  /// Register new JSON converters with addConverter<Foo>().
-  /// You should have used first the macro BT_JSON_CONVERTER
+  /**
+   * @brief Register new JSON converters with addConverter<Foo>().
+   * You should used first the macro BT_JSON_CONVERTER.
+   * The conversions from/to vector<T> are automatically registered.
+   */
   template <typename T>
   void addConverter();
 
@@ -121,7 +123,14 @@ class JsonExporter
   std::unordered_map<std::type_index, FromJonConverter> from_json_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
 {

include/behaviortree_cpp/python/types.h

@@ -2,10 +2,8 @@
 
 #include <pybind11/pybind11.h>
 
-#include "behaviortree_cpp/basic_types.h"
 #include "behaviortree_cpp/json_export.h"
-#include "behaviortree_cpp/contrib/json.hpp"
-#include "behaviortree_cpp/contrib/pybind11_json.hpp"
+
 #include "behaviortree_cpp/utils/safe_any.hpp"
 
 namespace BT
@@ -20,12 +18,12 @@ namespace BT
 template <typename T>
 bool fromPythonObject(const pybind11::object& obj, T& dest)
 {
-  if constexpr(nlohmann::detail::is_getable<nlohmann::json, T>::value)
+  auto dest_maybe = JsonExporter::get().fromJson<T>(obj);
+  if(dest_maybe.has_value())
   {
-    JsonExporter::get().fromJsonHelper<T>(obj, dest);
+    dest = dest_maybe.value();
     return true;
   }
-
   return false;
 }
 

python_examples/ex02_generic_data.py

@@ -7,7 +7,6 @@
 import numpy as np
 from btpy import BehaviorTreeFactory, SyncActionNode, NodeStatus, ports
 
-
 xml_text = """
  <root BTCPP_format="4" >
 
@@ -24,7 +23,7 @@
 """
 
 
-@ports(inputs=["position", "theta"], outputs=["out"])
+@ports(inputs=["position", "theta"], outputs=["out", "position"])
 class Rotate(SyncActionNode):
     def tick(self):
         # Build a rotation matrix which rotates points by `theta` degrees.
@@ -38,6 +37,7 @@ def tick(self):
 
         # Set the output.
         self.set_output("out", rotated)
+        self.set_output("position", position)
 
         return NodeStatus.SUCCESS
 

python_examples/ex05_type_interop.py

@@ -60,7 +60,7 @@ def tick(self):
 
 
 factory = BehaviorTreeFactory()
-factory.register_from_plugin("sample_nodes/bin/libdummy_nodes_dyn.so")
+factory.register_from_plugin("build/sample_nodes/bin/libdummy_nodes_dyn.so")
 factory.register(PutVector)
 factory.register(Print)
 

sample_nodes/dummy_nodes.h

@@ -198,6 +198,8 @@ inline void RegisterNodes(BT::BehaviorTreeFactory& factory)
                                std::bind(&GripperInterface::close, &grip_singleton));
   factory.registerNodeType<ApproachObject>("ApproachObject");
   factory.registerNodeType<SaySomething>("SaySomething");
+  factory.registerNodeType<RandomVector>("RandomVector");
+  factory.registerNodeType<PrintMapOfVectors>("PrintMapOfVectors");
 }
 
 }  // namespace DummyNodes

setup.py

@@ -5,12 +5,16 @@
 
 #include "behaviortree_cpp/json_export.h"
 #include "behaviortree_cpp/contrib/json.hpp"
-#include "behaviortree_cpp/contrib/pybind11_json.hpp"
 
 namespace BT
 {
 
-bool toPythonObject(const BT::Any& val, pybind11::object& dest)
+#if defined(_WIN32)
+__declspec(dllexport)
+#else
+__attribute__((visibility("default")))
+#endif
+    bool toPythonObject(const BT::Any& val, pybind11::object& dest)
 {
   nlohmann::json json;
   if(JsonExporter::get().toJson(val, json))