Provides macros for callback handling.

Example

defmodule CallbackModule do
  use Exop.Callback

  def process(operation, params, result, opts) do
    # your callback handling code here
  end
end

defmodule TestOperation do
  use Exop.Operation

  callback CallbackModule, return: true

  parameter :a, type: :integer
  parameter :b, type: :integer

  def process(%{a: a, b: b}), do: a + b
end

By using Exop.Callback you need to implement process/4 function which takes following params:

• operation module (TestOperation in the example above)
• params that were passed into the operation (%{a: 1, b: 2})
• an successful result which was returned by the operation.
• opts is an open keyword list for metadata passing.

Callback operation has no effect on the result. but trigger a callback after success coming handy to send PubSub prodcast or any side effect event without interrepting the main workflow.