---
title: "TIL: Pass a Hash to Flash"
author: "Yaroslav Shmarov"
date: "2022-02-22"
canonical_url: "https://blog.superails.com/flash-as-a-hash"
markdown_url: "https://blog.superails.com/flash-as-a-hash.md"
description: "Today I learned: You are free to pass a HASH to a flash message. Not just a string 😀 You can also register new flash types with add_flash_types This lets you…"
tags: ["rails","today-i-learned"]
license: "GNU AGPL v3. Credit Yaroslav Shmarov and link the canonical URL."
---

# TIL: Pass a Hash to Flash

Today I learned:

You are free to pass a HASH to a flash message. Not just a string 😀

```ruby
# app/controllers/posts_controller.rb
flash[:post_status] = "Success. Post created" # a string
flash[:post_status] = { title: "Success", subtitle: "Post created" } # a hash!
```

```ruby
# app/views/shared/_flash.html.erb
<% flash.each do |type, message| %>
  <%= type %>
  <%= message[:title] %>
  <%= message[:subtitle] %>
<% end %>
```

You can also register new flash types with [add_flash_types](https://api.rubyonrails.org/classes/ActionController/Flash/ClassMethods.html)

```ruby
# app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
  add_flash_types :toast
```

This lets you use

```diff
-redirect_to root_path, flash: { toast: "success" }
+redirect_to root_path, toast: "success"
```

- More about [ActionDispatch::Flash](https://api.rubyonrails.org/classes/ActionDispatch/Flash.html){:target="blank"} (official docs)
- [Dismissable Flash Messages with Hotwire without page refresh](https://blog.superails.com/turbo-hotwire-flash-messages){:target="blank"}