Subscribe to the Channel

Receive a Filtered Event Stream

Now that you set up a filter for the Order Filtered Channel, subscribe to this channel to receive only the order event messages that match the filter.

Install Streaming Monitor from the AppExchange

If you’re using a Trailhead Playground org, you should have the prerequisites for the Streaming Monitor app and you can proceed with the installation steps. If you aren’t using a Trailhead Playground org, make sure that Lightning Experience is enabled in your org.

Installation Steps  

In your Trailhead Playground, if you see a tab in your org labeled Install a Package, great! Follow these steps: 

1. Click the Install a Package tab.
   
2. Paste 04t1t000003Lgqi into the field.
   
3. Click Install.
   
4. Select Install for Admins Only, then click Install.
   

If you don't see the Install a Package tab, open the App Launcher (), find Playground Starter, and follow the steps.

If you don’t see the Playground Starter app, copy this package installation link and check out Install a Package or App to Complete a Trailhead Challenge  on Salesforce Help.

When the package is finished installing, you see a confirmation page and get an email to the address associated with your playground.

The Streaming Monitor app on AppExchange is developed by Salesforce Labs. It is used as an example tool in this project. Salesforce Labs supports this tool but not Salesforce. Streaming Monitor is also available as an open-source tool in GitHub that you can contribute to. Alternatively, you can use the empApi Lightning component in your custom Lightning app. 

Subscribe to the Channel and Receive a Filtered Event Stream

Use Streaming Monitor to subscribe to the channel that contains a filter. 

Subscribe to the Custom Channel

After you’ve installed Streaming Monitor, launch it in your playground to subscribe to the custom channel.

1. Click App Launcher, and enter Streaming Monitor in the search box. Select Streaming Monitor.
   
2. In the Streaming Monitor app, under Actions, click Subscribe to a channel.
   
3. Under Event type, select Custom Channel - Platform event.
   
4. For the channel, append Order_Filtered_Channel__chn. The full channel name is /event/Order_Filtered_Channel__chn.
   
5. Click Subscribe.
   
6. You get a popup that confirms the successful subscription. Dismiss it.
   

Keep the Streaming Monitor tab open so you can check the event messages received in the next step. The Streaming Monitor tab doesn’t save the event messages in the view. If you close the tab and reopen it, you can’t view the previous event messages, but you can retrieve them using a replay option.

Resources

• AppExchange: Streaming Monitor
• GitHub: streaming-monitor repository
• Component Reference: Emp API Lightning Web Component