I bought a sweet DJI FPV drone and I’m getting certified for commercial operation. It was more work than I expected – until you consider that you are basically the pilot of an aircraft. Better know the rules of our National airspace – now with 1000 acronyms! Don’t worry, got you covered on my wiki. Soon you will be reading these crazy charts…

CORS is dumb. CORS is here to stay. CORS has a bit of usefulness. As my daughter opined recently, cry me a river, build a bridge, and get over it.

After spending days on it, I now have a five minute fix for CORS in a dev environment where the frontend is split from the backend during development.

GIVEN:

  • a server that serves up your RESTful API using backend data
  • that same server, serving up your nicely bundled front end, after you bake it for prod
  • https in prod, and http in dev
  • a modern front end development environment that maximizes your local web development speed while also bundling it tight for prod ( 💕 Vite 💕 )

You may have been sailing along with that sweet setup for a while now. But then one day, CORS arrives in your neighborhood. Perhaps you realize your Node front end can now use native fetch(), how nice (at first). Or your browser just got updated and all of a sudden it’s very unhappy serving your JWT tokens. Any way you get there, you will probably hit CORS issues. They tell you you are a bad person for trying to reach your backend from your frontend. Bad dev!

The problem is that is actually now blocked as a cross-site request. This blockage is now ubiquitous. How else can you still get to your favorite awful monster sites if they are sideloading dozens of malware ads? Why should megasite be responsible for the ads they serve? Let the browser block them! We need to protect the sheeple!! But i digress…

To fix your CORS issues, quickly, you simply add proxying to your Vite environment. The proxy takes all your backend calls, sends them off, and when they return, gently stuffs all the weird painful CORS headers you need in the response to keep your frontend from having a seizure.

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [react()],
  server: {
    // For back end calls, make sure to use the API prefix.
    // Our vite dev environment will proxy those calls to the back end,
    // and return them to us, with fetch's xss concerns disabled via CORS:
    //    front -> proxy -> back -> proxy -> (ADD CORS) -> front
    proxy: {
      '/api': {
        'target': 'http://backend:8080',
        changeOrigin: true,
      },
    },
    port: 8008,
  },
})

Beautiful. In addition to that, if you can just slightly touch your server side cookie header to make it fit the CORS rulebook, you can get all that cross-site protection in prod, and never deal with a CORS issue in local dev again:

if (dev_environment) {
    cookie_header += " SameSite=Lax;";
  } else {
    cookie_header += " Secure; SameSite=Strict;";
  }

A better Trader has been a work-in-progress project of mine for a very long time. The web UI was done in vanilla javascript, with old school imports, and PHP-style server-generated html, then added jQuery, then bootstrap, then started removing jQuery, then moved towards more-static html with JSON payloads for the data, then pined for better node imports, then then then. You get the point.

I went too long without a rewrite, so I recently became a weekend warrior skeletoning up the next gen web ui. Parts include:

  • Vite due to its blazing hot-loading, tree-shaking, polyfilling goodness
  • React because it’s good enough and gets the job done
  • Bootstrap because I won’t have time to finish the mobile apps for a while

For my UIs, D3 is the most important library there is. So the skeleton is based on responsively displaying a handful of some of Mike Bostock’s greatest hits (imho). This was quite important to me because D3 examples have been somewhat obfuscated when they were migrated to Observables notebooks. The skeleton makes it much easier for me to quickly get working D3 examples by copying Mike’s Observables code into a cozy little container with all the bells and whistles in place.

Let me know what you think of it.

Reddit | Live Demo | GitLab | GitHub | Wiki

My little iPhone app is simple as I can manage (but no less, ha). SwiftUI is the new way, UIKit is the old way but huge, full of history – can I avoid it? It seems I can. I have login and logout, environment state across pages, tab views, REST API calls with JSON decoding, cookies, page navigation, etc. all working after the second busy weekend of work. And away we go!

I went swimming in the Atlantic for a couple hours. With my Samsung phone in my pocket.

So when I got an updated Android phone, I got an iPhone too. Time for some mobile app development.

(continued…)