The Details of Broadway Callbacks

Now that we have the tickets project set up, we can start writing some code. Once a message comes from the message broker, we want to use it to create a ticket in the database for the customer and send a confirmation email to them.

Broadway callbacks

To accomplish this, we will use the Broadway behavior to configure and start the data-ingestion pipeline. There are four callbacks available for us to implement:

• handle_message/3

• prepare_messages/2

• handle_failed/2

• handle_batch/4

This section will focus on the first three callbacks in the list.

Create bookings_pipeline.ex

First, we create a new file, bookings_pipeline.ex, in the lib folder. Then, we define the BookingsPipeline module in the following way:

defmodule BookingsPipeline do
  use Broadway

end

We also add use Broadway to bring in the Broadway ...