Sending a message to a Telegram bot

jsulm

@jenya7 Does that folder also contain the dll file?

jenya7

@jsulm said in Sending a message to a Telegram bot:

@jenya7 Does that folder also contain the dll file?

I ran a search in Qt folder on any ssl related files and found only
ssleay32.dll in C:\Qt\Tools\mingw730_64\opt\bin and C:\Qt\Tools\QtCreator\bin
Should I include the paths too?

jenya7

I have a problem.
This way it works - if I initialize explicitly with a string

telebot::telebot(QObject *parent) : QObject(parent)
{
       TelegramBot bot("my_api_key");
       QObject::connect(&bot, &TelegramBot::newMessage, this, &telebot::NewMessage);
}

But if I do it with variable

telebot::telebot(QObject *parent) : QObject(parent)
{
   if (!sys_params.bot_api_key.isNull() && !sys_params.bot_api_key.isEmpty())
   {
       TelegramBot bot(sys_params.bot_api_key);
       QObject::connect(&bot, &TelegramBot::newMessage, this, &telebot::NewMessage);
   }
}

I get the error
The inferior stopped because it received a signal from the operating system.
Signal name : SIGSEGV
Signal meaning : Segmentation fault

I see the constructor works before sys_params initialization although I set first line after window activation

int main(int argc, char *argv[])
{
    QFuture<uint32_t> discovered;

    QApplication a(argc, argv);

    MainWindow w;
    w.show();

    //here is sys_params initialization 
    SetupRun();
   
    //some other code

      return a.exec();
}

What should I do?

JonB

@jenya7 said in Sending a message to a Telegram bot:

Signal name : SIGSEGV

What should I do?

You are supposed to run your code in a debugger. It will stop on the seg fault, go to the stack trace window to see information about where this is occurring from your code/the code you call.

Since we have no idea what your sys_params.bot_api_key is or what is in it, and since you say introducing it causes a seg fault, that would be my first suspect.....

telebot::telebot(QObject *parent) : QObject(parent)
{
       TelegramBot bot("my_api_key");
       QObject::connect(&bot, &TelegramBot::newMessage, this, &telebot::NewMessage);
}

Your TelegramBot bot is a local variable, it will go out of scope and be destroyed at the end of this constructor. Same applies in your second code attempt. What do you think you are achieving with this code, because it is not right.

jenya7

@JonB said in Sending a message to a Telegram bot:

@jenya7 said in Sending a message to a Telegram bot:

Signal name : SIGSEGV

What should I do?

You are supposed to run your code in a debugger. It will stop on the seg fault, go to the stack trace window to see information about where this is occurring from your code/the code you call.

Since we have no idea what your sys_params.bot_api_key is or what is in it, and since you say introducing it causes a seg fault, that would be my first suspect.....
telebot::telebot(QObject *parent) : QObject(parent)
{
       TelegramBot bot("my_api_key");
       QObject::connect(&bot, &TelegramBot::newMessage, this, &telebot::NewMessage);
}
Your TelegramBot bot is a local variable, it will go out of scope and be destroyed at the end of this constructor. Same applies in your second code attempt. What do you think you are achieving with this code, because it is not right.

Yes I stop with a breakpoint at
if (!sys_params.bot_api_key.isNull() && !sys_params.bot_api_key.isEmpty())
the next step - refering to sys_params.bot_api_key generates the error.

It's a field of a structure

typedef struct
{
   //some fields
    QString bot_api_key;
}SYS_PARAMS;

SYS_PARAMS sys_params;

How can I do it global? It's not like I can instantiate it

TelegramBot bot;  
 telebot::telebot(QObject *parent) : QObject(parent) 
{
     bot = new TelegramBot ("my_api_key");  //is not allowed
}

jsulm

@jenya7 said in Sending a message to a Telegram bot:

the next step - refering to sys_params.bot_api_key generates the error

As @JonB asked: how does the stack trace look like after crash?

"How can I do it global?" - why should it be global? Simply make bot a class member...

JonB

@jenya7
As @jsulm has just written for the seg fault.

TelegramBot bot;  
     bot = new TelegramBot ("my_api_key");  //is not allowed

Why do you think this is "not allowed"? What does the compiler error message tell you, I would guess it's pretty clear?

jenya7

@jsulm said in Sending a message to a Telegram bot:

@jenya7 said in Sending a message to a Telegram bot:

the next step - refering to sys_params.bot_api_key generates the error

As @JonB asked: how does the stack trace look like after crash?

"How can I do it global?" - why should it be global? Simply make bot a class member...

It stops in qstring.h at
inline bool QString::isEmpty()
const { return d->size == 0; }

jsulm

@jenya7 This not stack trace...

jenya7

@JonB said in Sending a message to a Telegram bot:

@jenya7
As @jsulm has just written for the seg fault.
TelegramBot bot;  
     bot = new TelegramBot ("my_api_key");  //is not allowed
Why do you think this is "not allowed"? What does the compiler error message tell you, I would guess it's pretty clear?

TelegramBot bot; //here - error: no matching constructor for initialization of 'TelegramBot'

bot = new TelegramBot ("my_api_key");

jsulm

@jenya7 Please learn C++!
Your TelegramBot class has no constructor without parameter!
Also, if you want to allocate TelegramBot on the heap then bot needs to be a pointer. All these are absolute basics.

TelegramBot *bot;  
bot = new TelegramBot ("my_api_key");

JonB

@jenya7 said in Sending a message to a Telegram bot:

It stops in qstring.h at
inline bool QString::isEmpty()
const { return d->size == 0; }

In addition to @jsulm's excellent points. We don't know the scope of your sys_params (probably "global", yuck, don't do that), and:

typedef struct
{
   //some fields
    QString bot_api_key;
}SYS_PARAMS;
SYS_PARAMS sys_params;

We don't know whether you have written anything to the "some fields", or written directly into sys_params.

jenya7

@jsulm said in Sending a message to a Telegram bot:

@jenya7 This not stack trace...

1 QString::isEmpty qstring.h 937 0x28bd8
2 telebot::telebot telebot.cpp 10 0x56040
3 __static_initialization_and_destruction_0 telebot.cpp
4 0x5652c 4 _GLOBAL__sub_I_telebot.cpp(void) telebot.cpp 69 0x56588
5 __libc_csu_init 0xaf61c
6 __libc_start_main libc-start.c 264 0xb5ab96ac
7 _start 0x1c5dc

jenya7

@jsulm said in Sending a message to a Telegram bot:

@jenya7 Please learn C++!
Your TelegramBot class has no constructor without parameter!
Also, if you want to allocate TelegramBot on the heap then bot needs to be a pointer. All these are absolute basics.
TelegramBot *bot;  
bot = new TelegramBot ("my_api_key");

Thank you.

jenya7

@JonB said in Sending a message to a Telegram bot:

@jenya7 said in Sending a message to a Telegram bot:

It stops in qstring.h at
inline bool QString::isEmpty()
const { return d->size == 0; }

In addition to @jsulm's excellent points. We don't know the scope of your sys_params (probably "global", yuck, don't do that), and:
typedef struct
{
   //some fields
    QString bot_api_key;
}SYS_PARAMS;
SYS_PARAMS sys_params;
We don't know whether you have written anything to the "some fields", or written directly into sys_params.

If I comment out the constructor stuff - I see all fields of sys_params perfectly initialized. The problem - it gets to
bot = new TelegramBot (sys_params.bot_api_key); before it's initialized. The constructor goes first and then goes sys_params initialization (SetupRun(); in main.cpp).

Why do I get to the constructor? I don't instantiate any telebot object at all in the code.
When I get to the constructor I see
sys_params.bot_api_key = <not accessible>
how can it be?

JonB

@jenya7 said in Sending a message to a Telegram bot:

I don't instantiate any telebot object at all in the code.

You do if you hit the constructor! And putting a breakpoint there would should you where you do so from.

jenya7

@JonB said in Sending a message to a Telegram bot:

@jenya7 said in Sending a message to a Telegram bot:

I don't instantiate any telebot object at all in the code.

You do if you hit the constructor! And putting a breakpoint there would should you where you do so from.

I see...
In telebot.h I have extern telebot m_telebot;
and in telebot.cpp telebot m_telebot;
in order to work with the object in other parts of the project.
And when I include telebot.h in main.cpp it gets initialized before sys_params is accessible.

JonB

@jenya7 said in Sending a message to a Telegram bot:

and in telebot.cpp telebot m_telebot;

Indeed, and that is where it will get instantiated.

Since you say it is m_telebot, is it a member variable in some class? Or is it a (mis-named) global? You will not want it to be a truly global variable. If its constructor requires accessing sys_params, and that needs initialising first at run time (e.g. the SetupRun(); you showed), it is your job to ensure sys_params has been initialised before a telebot is created.

jenya7

@JonB said in Sending a message to a Telegram bot:

@jenya7 said in Sending a message to a Telegram bot:

and in telebot.cpp telebot m_telebot;

Indeed, and that is where it will get instantiated.

Since you say it is m_telebot, is it a member variable in some class? Or is it a (mis-named) global? You will not want it to be a truly global variable. If its constructor requires accessing sys_params, and that needs initialising first at run time (e.g. the SetupRun(); you showed), it is your job to ensure sys_params has been initialised before a telebot is created.

I did it this way

telebot m_telebot;

static TelegramBot *bot = nullptr;

telebot::telebot(QObject *parent) : QObject(parent)
{
     //empty constructor 
}

void telebot::Start(QString api_key)
{
    bot = new TelegramBot(api_key);

    QObject::connect(bot, &TelegramBot::newMessage, this, &telebot::NewMessage);

    bot->startMessagePulling();
}

and in main.cpp

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

     MainWindow w;
     w.show();

     SetupRun();

    m_telebot.Start(sys_params.bot_api_key);
    m_telebot.SendText(sys_params.bot_chat_id, "Control board is connected");
}

This way it works good.

JonB

@jenya7
I am happy this is working for you. I will just say that you really ought not have your global telebot and TelegramBot * variables, things would be better if you used classes and instances in C++. But that's up to you. So long as telebot m_telebot is global you really ought not have that m_ prefix on the name, that is conventionally used (by some) for class member variables and will lead to confusion for anyone looking at your code, as I suspected.