Tags: accept



Wednesday, December 1st, 2021

Best laid plans by Amy Hupe, content designer.

All of Amy’s writing recently has been absolutely wonderful, some of the best I’ve read in a long while, but I particularly needed this one.

I don’t know where we go from here, with this latest pandemic setback, but I do know that things will keep moving.

And if you feel bad today, feel bad. Feel sad or angry or scared or whatever it is you need to feel. Give yourself to yourself as you are.

Things will keep changing. Life will keep unfolding. We will keep going.

Wednesday, April 10th, 2019

Improving accessibility with accessibility acceptance criteria — Paul Hayes

Wouldn’t it be great if every component in your design system had accessibility acceptance criteria? Paul has some good advice for putting those together:

  • Start with accessibility needs
  • Don’t be too generic
  • Don’t define the solution
  • Iterate criteria

Sunday, June 17th, 2018

Detecting image requests in service workers

In Going Offline, I dive into the many different ways you can use a service worker to handle requests. You can filter by the URL, for example; treating requests for pages under /blog or /articles differently from other requests. Or you can filter by file type. That way, you can treat requests for, say, images very differently to requests for HTML pages.

One of the ways to check what kind of request you’re dealing with is to see what’s in the accept header. Here’s how I show the test for HTML pages:

if (request.headers.get('Accept').includes('text/html')) {
    // Handle your page requests here.

So, logically enough, I show the same technique for detecting image requests:

if (request.headers.get('Accept').includes('image')) {
    // Handle your image requests here.

That should catch any files that have image in the request’s accept header, like image/png or image/jpeg or image/svg+xml and so on.

But there’s a problem. Both Safari and Firefox now use a much broader accept header: */*

My if statement evaluates to false in those browsers. Sebastian Eberlein wrote about his workaround for this issue, which involves looking at file extensions instead:

if (request.url.match(/\.(jpe?g|png|gif|svg)$/)) {
    // Handle your image requests here.

So consider this post a patch for chapter five of Going Offline (page 68 specifically). Wherever you see:

if (request.headers.get('Accept').includes('image'))

Swap it out for:

if (request.url.match(/\.(jpe?g|png|gif|svg)$/))

And feel to add any other image file extensions (like webp) in there too.