Adding Access-Control-Allow-Origin Header to Bridgetown

I’ll keep this brief. I was playing around with <iframe>s for displaying previews of source code. The problem is they require certain cross-origin headers, in my case Access-Control-Allow-Origin.

Originally, I tried using the new Roda Initializer but to no avail. I don’t know if I did something wrong or what happened.

Anyways, I decided to try rack-cors and it worked for me!

Here’s what I did.

First, I added rack-cors to my Gemfile.

bundle add rack-cors

Then, I went to config.ru and made it look like the following:

# config.ru

require "bridgetown-core/rack/boot"
require "rack-cors"

Bridgetown::Rack.boot

use Rack::Cors do
  allow do
    origins '*'
    resource '*', headers: :any, methods: [:get, :post, :patch, :put]
  end
end

run RodaApp.freeze.app # see server/roda_app.rb

And here’s the diff.

# config.ru

require "bridgetown-core/rack/boot"
+ require "rack-cors"

Bridgetown::Rack.boot

+ use Rack::Cors do
+  allow do
+    origins '*'
+    resource '*', headers: :any, methods: [:get, :post, :patch, :put]
+  end
+ end

run RodaApp.freeze.app # see server/roda_app.rb

And now my static assets are served with the following header: Access-Control-Allow-Origin: "*"

Short, sweet, to the point.