The Ultimate Turbo Modal for Rails (UTMR)

There are MANY Turbo/Hotwire/Stimulus modal dialog implementations out there, and it seems like everyone goes about it a different way. However, as you may have learned the hard way, the majority fall short in different, often subtle ways. They generally cover the basics quite well, but do not check all the boxes for real-world use.

UTMR aims to be the be-all and end-all of Turbo Modals. I believe it is the best implementation and checks all the boxes. It is feature-rich, yet extremely easy to use.

Under the hood, it uses Stimulus, Turbo, el-transition, and optionally Idiomorph.

It currently ships in a two flavors: Tailwind CSS, and regular, vanilla CSS. It is easy to create your own variant to suit your needs. See lib/ultimate_turbo_modal/flavors/vanilla.rb for an example code.

• Extremely easy to use
• Fully responsive
• Does not break if a user navigates directly to a page that is usually shown in a modal
• Opening a modal in a new browser tab (ie: right click) gracefully degrades without having to code a modal and non-modal version of the same page
• Automatically handles URL history (ie: pushState) for shareable URLs
• pushState URL optionally overrideable
• Seamless support for multi-page navigation within the modal
• Seamless support for forms with validations
• Seamless support for Rails flash messages
• Enter/leave animation (fade in/out)
• Support for long, scrollable modals
• Properly locks the background page when scrolling a long modal
• Click outside the modal to dismiss
• Option to whitelist CSS selectors that won't dismiss the modal when clicked outside the modal (ie: datepicker)
• Keyboard control; ESC to dismiss
• Automatic (or not) close button

A demo application can be found at https://github.com/cmer/ultimate_turbo_modal-demo. A video demo can be seen here: https://youtu.be/BVRDXLN1I78.

1. Install the gem and add to the application's Gemfile by executing:

   $ bundle add ultimate_turbo_modal

2. Install the npm package:

   $ yarn add ultimate_turbo_modal

   • or -

   $ bin/importmap pin ultimate_turbo_modal

3. Add the following as the first element in the body tag of views/layouts/application.html.erb:

<%= turbo_frame_tag "modal" %>

4. Set your desired flavor and default configuration at app/config/initializers/ultimate_turbo_modal.rb.

UltimateTurboModal.configure do |config|
  config.flavor = :tailwind
  config.padding = true
  config.advance = true
  config.close_button = true
  config.header = true
  config.header_divider = true
  config.footer_divider = true
  config.allowed_click_outside_selector = nil
end

5. Register the Stimulus controller in app/javascript/controllers/index.js adding the following lines at the end.

import setupUltimateTurboModal from "ultimate_turbo_modal";
setupUltimateTurboModal(application);

6. If using the Tailwind flavor, add the following to tailwind.config.js:

// For npm/yarn
const { getUltimateTurboModalPath } = require('ultimate_turbo_modal/gemPath');

// If using Importmaps, use the following instead:
// const { execSync } = require('child_process');
//
// function getUltimateTurboModalPath() {
//  const path = execSync('bundle show ultimate_turbo_modal').toString().trim();
//  return `${path}/**/*.{erb,html,rb}`;
//}

and then in the content section, add getUltimateTurboModalPath() as follow:

content: [
 './public/*.html',
 './app/helpers/**/*.rb',
 './app/javascript/**/*.js',
 './app/views/**/*.{erb,haml,html,slim,rb}',
 getUltimateTurboModalPath()
]

1. Optionally (but recommended), configure UTMR to use Idiomorph. See below for details.

1. Wrap your view inside a modal block as follow:

<%= modal do %>
  Hello World!
<% end %>

2. Link to your view by specifying modal as the target Turbo Frame:

<%= link_to "Open Modal", "/hello_world", data: { turbo_frame: "modal" } %>

Clicking on the link will automatically open the content of the view inside a modal. If you open the link in a new tab, it will render normally outside of the modal. Nothing to do!

If you need to do something a little bit more advanced when the view is shown outside of a modal, you can use the #inside_modal? method as such:

<% if inside_modal? %>
  <h1 class="text-2xl mb-8">Hello from modal</h1>
<% else %>
  <h1 class="text-2xl mb-8">Hello from a normal page render</h1>
<% end %>

Adds padding inside the modal.

Shows or hide a close button (X) at the top right of the modal.

When opening the modal, the URL in the URL bar will change to the URL of the view being shown in the modal. The Back button dismisses the modal and navigates back.

If a URL is specified as a String, the browser history will advance, and the URL shown in the URL bad will be replaced by the URL specified.

Title to display in the modal header. Alternatively, you can set the title with a block.

Whether to display a modal header.

Whether to display a divider below the header.

Whether to display a divider above the footer. The divider will not appear if no footer was specified.

A string of CSS selectors that can be clicked outside of the modal without dismissing the modal. Useful for elements such as datepickers.

<%= modal(padding: true, close_button: false, advance: false) do %>
  Hello World!
<% end %>

<%= modal(padding: true, close_button: false, advance: "/foo/bar") do %>
  Hello World!
<% end %>

You can set a custom title and footer by passing a block. For example

<%= modal do |m| %>
  <% m.title do %>
    <div>My Title</div>
  <% end %>

  Modal body

  <% m.footer do %>
    <input type="submit" form="myform">Submit</input>
  <% end %>
<% end %>

Idiomorph can morph Turbo Frame responses to allow seemless navigation within Turbo Frames without having to hide and reopen the modal. This is needed to prevent the fade out / fade in animations from repeating when navigating within the modal.

You could optionally not use the code below if you do not intend to allow navigation within the modal.

Note that Turbo 8 will include Idiomorph by default.

In the meantime, add <script src="https://unpkg.com/idiomorph"></script> to your HTML .

And the following code to application.js:

addEventListener("turbo:before-frame-render", (event) => {
  event.detail.render = (currentElement, newElement) => {
    Idiomorph.morph(currentElement, newElement, {
      morphStyle: 'innerHTML'
    })
  }
})

Thanks to @joeldrapper and @konnorrogers for all the help!

Bug reports and pull requests are welcome on GitHub at https://github.com/cmer/ultimate_turbo_modal.

The gem is available as open source under the terms of the MIT License.