Question about message parsing code

[PierreSt]

Hello,

I am trying to understand the code in MySensorBase.cpp.
In

Code: Select all

void MySensorsBase::ParseLine()
{
    if (m_bufferpos<2)
        return;
    std::string sLine((char*)&m_buffer);

    //_log.Log(LOG_STATUS, sLine.c_str());

    std::vector<std::string> results;
    StringSplit(sLine, ";", results);
    if (results.size()<5)
        return; //invalid data

    int node_id = atoi(results[0].c_str());
    int child_sensor_id = atoi(results[1].c_str());
    _eMessageType message_type = (_eMessageType)atoi(results[2].c_str());
    int ack = atoi(results[3].c_str());
    int sub_type = atoi(results[4].c_str());
    std::string payload = "";
    if (results.size() >= 6)
    {
         for (size_t ip = 0; ip < results.size() - 5; ip++)
            {
                 payload = results[5+ip];
            }
    }
[...]

If I understand the above code properly:
If the payload is a ";" separated list of values (like for a V_POSITION of a S_GPS for example) then only the last value will be considered as the "payload". Equally if on a V_TEXT, the text to be displayed contains a ";", then it will be truncated to the last "sub-string"

(cf MySensors website on the serial API:
V_POSITION 49 GPS position and altitude. Payload: latitude;longitude;altitude(m). E.g. "55.722526;13.017972;18" S_GPS)

Have I missed something?

Thanks for the clarification,

Pierre

[gizmocuz]

V_POSITION is not implemented (yet), and all values are in the 'results variable:

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StringSplit(sLine, ";", results);

I do agree that the person making the V_POSITION could have better picked another separator

[PierreSt]

In 'results', yes, but not in 'payload' which is used in the further processing.
In the case of the gps position, results.size would be 8,
Payload would successivelly be assigned results(5), results(6) and finally results(7). At the end of the loop, payload would only contain the altitude.
Equally if I have a v_text which is "some text; some further text". The final 'payload' would only be "some further text". This restriction on the ; character is not mentioned in MySensors.
Perhaps the routine could be:

for (size_t ip)
{ payload += "," + result[5+ip] }

(Cleaned to avoid the leading , of course)

Pierre

[gizmocuz]

yes, so thats not a big issue to combine the rest of the results back to 1 payload ?

i think it is already done... did you check it ?

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	if (results.size() >= 6)
	{
		for (size_t ip = 0; ip < results.size() - 5; ip++)
		{
			payload = results[5+ip];
		}
	

}

or are you just assuming it did not work ?

[PierreSt]

I am not making any assumptions really (especially not of buggy behaviour), I am trying to understand how things work. Indeed for now I have not tested anything, I have just read the code. Hence the initial question "Have I missed something?"
I will not have my hand on the stuff needed to test for real anything before probably next week.

I actually find Domoticz code really interresting and very elegant. There are certain things I have not yet been able to grasp (the latest is the link between the UI and the mainworker, especially the error reporting mechanism - how/where the return bool from SwitchLight() is used for example), hence my questions. If I am becoming annoying, just let me know and I'll stop pestering.

And to conclude, thanks for making Domoticz available to us, it really is cool software.

Pierre

[gizmocuz]

No worries
If you can include the GPS system, you might get more understanding.
Else, can you point me to the hardware page for this sketch ?

[PierreSt]

It seems that indeed, the payload gets truncated. I have made a test with a S_INFO sensor sending a V_TEXT. Below the result of the serial monitor and domoticz results:

screenshot_domoticz_truncated_payload.png (264.16 KiB) Viewed 1469 times

[PierreSt]

Indeed, hence my initial question about the code. Why go through a loop to iterate over all values. If the purpose was to take only the last one a "payload = results[size-1]" would have been enough.

Having said that, looking at MySensors sensors/variables types, it seems that only the V_POSITION is meant to have a ; delimited list of values as payload. And that sensor is not implemented in Domoticz.
The thing with the V_TEXT is IMHO just a corner case by-product.

Pierre