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Elixir Cookbook

Elixir Cookbook

By : Paulo Pereira
4.5 (2)
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Elixir Cookbook

Elixir Cookbook

4.5 (2)
By: Paulo Pereira

Overview of this book

This book is intended for users with some knowledge of the Elixir language syntax and basic data types/structures. Although this is a cookbook and no sequential reading is required, the book’s structure will allow less advanced users who follow it to be gradually exposed to some of Elixir’s features and concepts specific to functional programming. To get the most out of this book, you need to be well versed with Erlang.
Table of Contents (11 chapters)
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10
Index

Implementing topics


Topics in Phoenix are a form of implementing the publisher-subscriber pattern.

In this recipe, we will create a simple counter in a form of a function that will subscribe a channel.

In TodosController, we will broadcast an event every time a request is made to the index action. The counter will then receive the notification and will output a message to the console with the number of times the action was called.

Getting ready

To get started, we will take the code resulting from the previous recipe. Open a code editor and prepare to add pub/sub to the Phoenix application.

How to do it…

To implement topics in the Phoenix application, follow these steps:

  1. Edit TodoController to make it look like this:

    defmodule Todo.TodosController do
      use Phoenix.Controller
    
      plug :action
      plug :render
    
      def index(conn, _params) do
        todos = [%{id: 1, task: "Write the other controller actions!", created_at: "2014-12-13", status: "pending"}, %{id: 2, task: "Create Views", created_at: "2014-12...

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