persisted_variable.h

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#ifndef AUBO_SCOPE_PERSISTED_VARIABLE_H
#define AUBO_SCOPE_PERSISTED_VARIABLE_H
 
#include <aubo_caps/domain/variable/variable.h>
 
namespace arcs {
namespace aubo_scope {
ARCS_CLASS_FORWARD(PersistedVariable);
 
/**
 * ingroup ApplicationApi
 * This interface represents variables stored with the installation. These
 * variables are defined in the installation and will exist even when a robot is
 * turned off and on.
 */
class ARCS_ABI_EXPORT PersistedVariable : public Variable
{
public:
    PersistedVariable(PersistedVariable &f);
    PersistedVariable(PersistedVariable &&f);
    virtual ~PersistedVariable();
 
    /**
     * @ingroup PersistedVariable
     * \chinese
     * 持久化变量无法保证始终存在。当终端用户加载不包含该变量的不同安装或删除该变量时，
     * 持久化变量将不可用。如果变量无法解析，存储了PersistedVariable的程序节点将变
     * 为未定义。
     * @return 如果持久化变量可解析（即存在于当前安装中）返回<code>true</code>。
     * \endchinese
     * \english
     * A persisted variable can not be guaranteed to be present. This method can
     * be used to determine, if the variable is present.
     *
     * The persisted variable will not be present, if the end user loads a
     * different installation which does not contain the variable, or if the
     * variable is deleted by the end user.
     *
     * A program node storing a <code>PersistedVariable</code> in its Data
     * Model will be undefined if the variable cannot be resolved (i.e. the
     * variable is not present).
     *
     * @return <code>true</code>, if this persisted variable is resolvable (i.e.
     * present in the current installation).
     * \endenglish
     */
    bool isResolvable();
 
protected:
    PersistedVariable();
 
private:
    friend class DataSwitch;
    void *d_{ nullptr };
};
 
struct PersistedVariableFilter
{
    bool operator()(VariablePtr var)
    {
        return std::dynamic_pointer_cast<PersistedVariable>(var) != nullptr &&
               var->getType() == Variable::VALUE_PERSISTED;
    }
};
 
} // namespace aubo_scope
} // namespace arcs
#endif // AUBO_SCOPE_PERSISTED_VARIABLE_H