script_node.h

/*  Copyright (C) 2022-2025 Davide Faconti -  All Rights Reserved
 *
*
*   Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
*   to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
*   and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*   The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
*   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
*   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
 
#pragma once
 
#include "behaviortree_cpp/action_node.h"
#include "behaviortree_cpp/scripting/script_parser.hpp"
 
namespace BT
{
/**
 * @brief The ScriptNode executes a piece of script code to set or modify
 * entries in the Blackboard.
 *
 * The script is passed via the input port "code" and can use the BT++ scripting
 * language syntax. For instance:
 *
 *   <Script code=" msg:='hello world' " />
 *   <Script code=" A:=42; B:=3.14 " />
 *
 * The node always returns SUCCESS after executing the script.
 */
class ScriptNode : public SyncActionNode
{
public:
  ScriptNode(const std::string& name, const NodeConfig& config)
    : SyncActionNode(name, config)
  {
    setRegistrationID("ScriptNode");
 
    loadExecutor();
  }
 
  static PortsList providedPorts()
  {
    return { InputPort<std::string>("code", "Piece of code that can be parsed") };
  }
 
private:
  virtual BT::NodeStatus tick() override
  {
    loadExecutor();
    if(_executor)
    {
      Ast::Environment env = { config().blackboard, config().enums };
      _executor(env);
    }
    return NodeStatus::SUCCESS;
  }
 
  void loadExecutor()
  {
    std::string script;
    if(!getInput("code", script))
    {
      throw RuntimeError("Missing port [code] in Script");
    }
    if(script == _script)
    {
      return;
    }
    auto executor = ParseScript(script);
    if(!executor)
    {
      throw RuntimeError(executor.error());
    }
    else
    {
      _executor = executor.value();
      _script = script;
    }
  }
 
  std::string _script;
  ScriptFunction _executor;
};
 
}  // namespace BT