Custom Group Topic name does not work

[MrEcosse]

Perform all steps below and tick them with [x]

• [x ] Check the related part of the Documentation
• [x ] Update openHASP to the latest version
• [ x] Reproduce the issue and describe all steps

Describe the bug

The MQTT group topic is provided to enable sending an MQTT message to multiple selected plates simultaneously. The default name setting is plates and if this is left unchanged the group topic works. However, if you change the group topic name in the web interface it does not work. The GUI shows the new name but the plate still only subscribes to the 'plates' group topic. Effectively this means it is not possible to use the Group Topic function as intended.

To Reproduce

On a plate create an object such as:

{"page":1,"id":1,"obj":"label","x":10,"y":10,"w":120,"h":60,"text":"---","click":0,"text_font":42,"parentid":10}

Then from MQTT Explorer (or Home Assistant) send the command hasp/plates/command/p1b1.text with the value Hello World and the text will change.

Now rename the Group Topic to mygroup. Save and restart the plate.

Then from MQTT Explorer (or Home Assistant) send the command hasp/mygroup/command/p1b1.text with the value Have a Nice Day and the text will not change.

Confirmed by smcgann99 on Discord

openHASP rc11

Expected behavior

The ability to use a custom group name as described in the documentation. Otherwise, the Group Topic has the same functionality as the Broadcast Topic

Screenshots or video

[marsman7]

I can't understand that. I have copied the jsonl line but deleted "parentid". I can send an MQTT group message to the label without any problems.

Please show more of your "pages.jsonl" and the complete text at Group Topic.

[MrEcosse]

If you send a message with the default group name of pages it all works OK. It is when you change the name of the group it no longer works.

[marsman7]

it remains "hasp/plates/command/p1b1.text" despite group topic "hasp/mygroup/%topic%" I show later in source code.

[marsman7]

I have found the place where the problem lies but I have no explanation for the error.

In "src/mqtt/hasp_mqtt_esp.cpp" i have added 2 LOGs

String mqttGetTopic(Preferences preferences, String subtopic, String key, String value, bool add_slash)
{
    String topic = preferences.getString(key.c_str(), value);

    LOG_INFO(TAG_MQTT,"mqttGetTopic 1 key[%s] topic[%s] value[%s]", key.c_str(), topic.c_str(), value.c_str());
    LOG_INFO(TAG_MQTT, "mqttGetTopic 2 key[%s] topic[%s]", FP_CONFIG_GROUP_TOPIC, preferences.getString(FP_CONFIG_GROUP_TOPIC, "notfound").c_str());

    topic.replace(F("%hostname%"), haspDevice.get_hostname());
    topic.replace(F("%hwid%"), haspDevice.get_hardware_id());
    topic.replace(F("%topic%"), subtopic);
    topic.replace(F("%prefix%"), MQTT_PREFIX);

    if(add_slash && !topic.endsWith("/")) {
        topic += "/";
    }
    return topic;
}

This function is called twice in "void mqttStart()". The output of the second log line has exactly the same parameters in both calls but the value of Topic is different. Why?

MQTT: mqttGetTopic 1 key[node_t] topic[hasp/foo/%topic%] value[hasp/%hostname%/%topic%]
MQTT: mqttGetTopic 2 key[group_t] topic[hasp/mygroup/%topic%]
MQTT: mqttGetTopic 1 key[group_t] topic[hasp/plates/%topic%] value[hasp/plates/%topic%]
MQTT: mqttGetTopic 2 key[group_t] topic[notfound]

"preferences.getString" returns different results.

[marsman7]

On the second call of "mqttGetTopic" "preferences.getString" returns the error INVALID_HANDLE

[stefan242]

Here the backlink to my similar issue: #686

[marsman7]

The problem ist multible call of "mqttGetTopic" and in it the call of "preferences.getString".

In first call all ok, in all further calls no longer.

please review my fix.

[MrEcosse]

Thanks all for looking into and fixing this

[smcgann99]

@MrEcosse Is this working for you now ? If so you can close the issue ?

[marsman7]

For your information: The fix from above is a workaround but it works well. I have continued to search for the actual cause.

The actual problem is the parameter transfer from "preferences" to the function mqttGetTopic. The function works with a copy of "preferences". This can be fixed if only the pointer to "preferences" is passed to the function "mqttGetTopic".

String mqttGetTopic(Preferences *preferences, String subtopic, String key, String value, bool add_slash)

Only add the asterisk and call the function with

mqttNodeCommandTopic = mqttGetTopic(&preferences, subtopic, FP_CONFIG_NODE_TOPIC, MQTT_DEFAULT_NODE_TOPIC, false);

Only add ampersand. This means that you are not working with a copy of "preferences" but with the same instance. Working with the copy only works with the first call of "mqttGetTopic" from the second call onwards.

[MrEcosse]

Sorry, I have been travelling. Will be able to test tomorrow and report.

[MrEcosse]

All good with RC12