Event name with slash

Troubleshooting
1

I have implemented a distributed set of sensors all communicating with publishing / subscribing to event names with a consistent namespace in the event names. Basically they look like sensor/temperature/request. Both the publish and subscribe events work swimmingly, but now that I’m developing a JS front-end I’m seeing 404 errors when trying to get the web browser to subscribe to the event names as they are above.

When I do onEvent for ‘sensor’ and ‘sensor/’ it works but when I add ‘sensor/temperature’ it with the 404 error. Is there any workaround for this?

2

If you subscribe to ‘sensor’, you should get all events with that name. Since the eventname is part of the SSE, you can filter them on the JS side(?)

3

@Moors7 thanks for the reply. While I could do that, I’d prefer to not have to process every event, just the ones that match the event path I specify. I’m just hoping there is some way to do this.

4

I wouldn’t know of a way to do that off the top of my head. Personally I’d go with the method I described above, since that requires only one listener. You can use if/else or switch/case statements to filter out the events you’re interested in. I don’t think that it would hurt too bad, performance-wise.
For alternatives, I’m going to refer you to the likes of @bko who undoubtedly knows more about these things than I do.

5

in this handler, similarly I’m only interested in the first response from my gmail webhook, it always has my gmail unread count. If there is dozens of returns, I only care to handle the one with the /0 added to the response:

void webhookHandler(const char *event, const char *data)
{
  DEBUG_PRINTLN("Responding to webhook...");
  DEBUG_PRINTLN(event);  // just for debugging to see how the webhook was actually called
  DEBUG_PRINT("Webhook is ");
  DEBUG_PRINT(strlen(data));  // debug payload length
  DEBUG_PRINT(" bytes and contains: ");
  DEBUG_PRINTLN(data);
  if (strstr(event, "my_gmail/0"))  //<<<<<<<<<<<<<<<<<<<<<<<<<<< here
  {
    gotGmailFeed(event, data);
  }
  else if(strstr(event, "current_weather"))
  {
    gotWeather(event, data);
  }
  else if (strstr(event, "forecast_weather"))
  {
    gotForecast(event, data);
  }
  else if (strstr(event, "sun_time"))
  {
    gotSunTime(event, data);
  }
}

I’m subscribing with hooks that contain the Photon’s ID:

  String responseTopic = System.deviceID();
  Particle.subscribe(responseTopic, webhookHandler, MY_DEVICES);

the webhook appends its identification to the core’s ID:

{
    "event": "my_gmail",
    "url": "https://<USERNAME>:<PASSWORD>@mail.google.com/mail/feed/atom/",
    "requestType": "POST",
	"headers": null,
	"query": null,
	"responseTemplate": null,
	"responseTopic": "{{SPARK_CORE_ID}}_my_gmail",
	"json": null,
	"auth": null,
	"coreid": null,
	"deviceid": null,
	"mydevices": true
}
1 Like
6

Hi @drukz

I am not sure why you would be getting a 404 from the event endpoint–I thought you could write “sensor/temperature/anything-I-want-up-to-some-length-limit” etc. I cannot seem to get a 404 out of particle subscribe, for instance.

Maybe something else is going wrong with your code in this case–have you tried poking around with a debugger? Or you could try the CLI and particle subscribe or even curl.