It’s great how easy particle allows you to publish an event and subscribe to it from other device. What I would like to do is determine which device sent the event. I could send the Device id in the event data, but I was hoping there is another way as I really don’t enjoy parsing strings in C++. I can’t think that this is a unique requirement. A best practice would be appreciated as well.
If you read the docs on publish() and subscribe() you will see that it may be easier than you fear.
I am not sure if I understand what you mean. A subscriber get’s two pieces of information from an event, the full event name and and data which may have been sent with it. If I need to know the device which sent the event, I guess the only way is to include that information in the data somehow. Any other suggestions?
how about the event name?
thisDevice publishes like this:
Particle.publish("thisDevice", "thisData", 60, PRIVATE);
otherDevice subscribes like this:
Particle.subscribe("thisDevice", webhookHandler, MY_DEVICES);
right from the docs:
A subscription works like a prefix filter. If you subscribe to “foo”, you will receive any event whose name begins with “foo”, including “foo”, “fool”, “foobar”, and “food/indian/sweet-curry-beans”.
device 42 published here:
Particle.publish("thisEvent_Device_42", "thisData", 60, PRIVATE);
the other device waits for all thisEvent events:
Particle.subscribe("thisEvent", webhookHandler, MY_DEVICES);
and handles them like this:
void webhookHandler(const char *event, const char *data)
// do device 42 stuff
else if (strstr(event, "Device_43"))
// do device 43 stuff
This is an interesting approach, thank you.