Programming Phoenix 1.4

Creating the Channel

It’s time to write some code to process connections. To review what you know so far, a channel is a conversation on a topic. Our topic has an identifier of videos:video_id, where video_id is a dynamic ID matching a record in the database. In our application, we want a user to get all events for a topic, which to us means a user will get all annotations for a given video, regardless of who created them.

More generally, at their most basic level, topics are strings that serve as identifiers. They often take the form of topic:subtopic, where topic is often a resource name and subtopic is often an ID, but any string is a valid topic.

Since topics are organizing concepts, we’ll include topics where you’d expect: as parameters ...