@rubyonjets/ujs-compat

UJS compat library for Ruby on Jets and API Gateway.

Overview

The @rails/ujs package adds unobtrusive JavaScript scripting support for Rails. This is typically done with:

yarn add @rails/ujs

Call rails ujs code:

app/javascript/packs/application.js

import Rails from "@rails/ujs"
Rails.start()

How Rails UJS Works

1. The @rails/ujs package registers click handlers to links with the data-delete attribute. Example: <a data-confirm="Are you sure?" rel="nofollow" data-method="delete" href="/posts/123">Destroy</a>
2. When the link is clicked, @rails/ujs creates a hidden form and submits the request as a POST request with a hidden field _method=delete.
3. The Rack::MethodOverride middleware is used to then adjust POST to DELETE request appropriately.

Essentially, a DELETE http request is mimiced using a POST http request. It all happens transparently, so developers don't really notice the magic happening behind the scenes.

The Issue

Unfortunately API Gateway REST APIs require actual DELETE requests to the resource, not mimiced POST requests. Example:

DELETE /posts/123

Sending a POST /posts/123 with a _method=delete will not work with API Gateway because the POST /posts/123 route points to the posts#update method API Gateway.

The Fix

To fix the issue, this javascript library adds click handlers that intercept @rails/ujs handlers and sends an AJAX DELETE request correctly.

Usage

yarn add @rubyonjets/ujs-compat

And then add the Jets ujs-compat code below the Rails ujs code.

app/javascript/packs/application.js

import jquery from 'jquery'
window.$ = jquery
import Jets from "@rubyonjets/ujs-compat"
Jets.start()

Dependencies

This package is dependencies on jquery. You should configure your own jquery.

Thoughts and Considerations

• Considered putting POST /posts/123 to the posts#delete action instead of posts#update. But that feels like unexpected behavior.
• Considered adding logic at the lambda handlers processing logic to convert posts#update actions with _method=delete to call posts#delete. This will make the logic closer to what Rack::MethodOverride does but again feels a little bit confusing.
• So went with javascript library to handle things earlier. An actual DELETE request is sent via AJAX to API Gateway.
• Open to suggestions and improvements.