blackboard_precondition.h

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/*  Copyright (C) 2018 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.
*
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*/

#ifndef DECORATOR_BLACKBOARD_PRECONDITION_NODE_H
#define DECORATOR_BLACKBOARD_PRECONDITION_NODE_H

#include "behaviortree_cpp/decorator_node.h"

namespace BT
{
template <typename T>
class BlackboardPreconditionNode : public DecoratorNode
{
  public:
    BlackboardPreconditionNode(const std::string& name, const NodeParameters& params)
      : DecoratorNode(name, params)
    {
        if( std::is_same<T,int>::value)
            setRegistrationName("BlackboardCheckInt");
        else if( std::is_same<T,double>::value)
            setRegistrationName("BlackboardCheckDouble");
        else if( std::is_same<T,std::string>::value)
            setRegistrationName("BlackboardCheckString");
    }

    virtual ~BlackboardPreconditionNode() override = default;

    static const NodeParameters& requiredNodeParameters()
    {
        static NodeParameters params = {{"key", ""}, {"expected", "*"}};
        return params;
    }

  private:
    virtual BT::NodeStatus tick() override;
};

//----------------------------------------------------

template<typename T> inline
NodeStatus BlackboardPreconditionNode<T>::tick()
{
    std::string key;
    T expected_value;
    T current_value;

    getParam("key", key);
    setStatus(NodeStatus::RUNNING);

    // check if the key is present in the blackboard
    if ( !blackboard() ||  !(blackboard()->contains(key)) )
    {
        return NodeStatus::FAILURE;
    }

    if( initializationParameters().at("expected") == "*" )
    {
        return child_node_->executeTick();
    }

    bool same = ( getParam("expected", expected_value) &&
                  blackboard()->get(key, current_value) &&
                  current_value == expected_value ) ;
    if(same)
    {
        return child_node_->executeTick();
    }
    else{
        if( child()->status() == NodeStatus::RUNNING)
        {
            haltChild();
        }
        return NodeStatus::FAILURE;
    }

}

}

#endif