For Example: reference methods [Listen] and [PubSub] (send Extension PubSub message)

Robot · October 3, 2020, 2:26pm

Please tell where can find code examples of how to use the Listen function together with PubSub?
(I’m sending a request like “Example Request #1 (Channel)” [link] from my EBS and my extension using the Listen method should pick it up, but how exactly does that happen?)

BarryCarlyon · October 3, 2020, 2:30pm

Here you go

Specifically this example covers the config service and PubSub together

You save the config, then push the same config out over PubSub.

As config in the config object is only updated via onChanged ONCE per page load on first call of that function. So updates to config have to be sent to the frontend another way.

So to update config you need to use the pubsub service

github.com

BarryCarlyon/twitch_misc/blob/main/extensions/config_service/set_n_publish_frontend.js#L21

    
      
                      global_config.content = JSON.parse(global_config.content);
                      configureExtension(global_config.content);
                  } catch (e) {
                      // this accounts for JSON parse errors
                      // just in case
                  }
              }
          });
          
          
// setup a listen on the global pubsub topic
          window.Twitch.ext.listen('global', function (topic, contentType, message) {
              try {
                  message = JSON.parse(message);
              } catch (e) {
                  // this accounts for JSON parse errors
                  // just in case
                  return;
              }
          
          
    // check that it's the exepected event
              if (message.event == 'configure') {

Is how to listen in the front end (on global)

github.com

BarryCarlyon/twitch_misc/blob/main/extensions/config_service/set_n_publish.js#L101

    
      
          // you can only set the config 12 times a minute per segment
          console.error('Store Config OK', resp.statusCode, resp.headers['ratelimit-ratelimiterextensionsetconfiguration-remaining'], '/', resp.headers['ratelimit-ratelimiterextensionsetconfiguration-limit']);
          
          
// we don't care too much about the statusCode here
          // but you should test it for a 204
          
          
// lets also send the same information to pubsub
          // so running instances get the update
          
          
// we'll pubsub to the all/global message line
          return got({
              url: "https://api.twitch.tv/extensions/message/all",
              method: "POST",
              headers: {
                  "Client-ID": config.client_id,
                  "Content-Type": "application/json",
                  "Authorization": "Bearer " + sigPubSub
              },
              body: JSON.stringify({
                  "message": JSON.stringify({
                      event: "configure",

Is the actual send for the global topic, but refer to further up the file for the Authentication construction

Robot · October 3, 2020, 5:03pm

Thanks for the examples.
Did I understand correctly that if, for example, I need to run a function in my interface, then I have to write its launch here?

function configureExtension(the_config) {
// do whatever you want with your config
// (re)build the extension
}

BarryCarlyon · October 3, 2020, 5:04pm

You can either do that or do it directly inside onChanged

there is no right/wrong way