Javascript30 Lesson 11

What I learned from lesson 11 of JavaScript30

Lee Keitel

4 minute read

Lesson 11 has been the most fun so far. This lesson looked at creating custom HTML5 video controls. Browsers have builtin controls for video and audio elements but they don't offer all the features one may want. Also, they typically don't fit stylistically with the rest of a site. In this case, custom controls can be created using CSS and JavaScript to add functionality and fit the style and flow of a site.

What I Learned

In this lesson I gained a better understanding of how video, and by extension audio, elements can be manipulated both in style and functionality. One feature I find very helpful is the ability to change the playback speed. Recently I've been increasing the speed of any video or podcast I watch/listen to. We can process information far faster than we can speak it. This makes it where a piece of media can be played back much faster but still be able to understand everything that's said. Right now I'm up to 1.3x and working up to maybe 1.5x.

For this lesson I watched the video first and then implemented it the next day without referencing the video again. For the most part my code turned out the same but I did have to look up a few things just to remember what was what.

I only made a couple changes the the original project. I set the max playback rate to 3 instead of 2 and set the progress bar to flex-basis: 0; to start. Otherwise the progress bar was already half full when the video hadn't even started yet.

A challenge Wes proposed was to implement fullscreen functionality. I didn't realize the rabbit hole I was about to enter as I thought to myself, “That can't be too hard.” Apparently although there is a Fullscreen API spec, each browser still has it behind vendor prefixes. There also the problem of some browsers supporting and older version of the spec instead of the latest. What this means is to support all browsers (IE 11+, Evergreen) you need an if statement like so:

if (player.requestFullscreen) { // Actual spec
} else if (player.webkitRequestFullScreen) { // WebKit engine
} else if (player.mozRequestFullScreen) { // Gecko engine
} else if (player.msRequestFullScreen) { // Microsoft (Trident/EdgeHTML)

This is the same for nearly every aspect of the API. If you want to determine if the site is currently in fullscreen mode, the spec says check document.fullscreenElement. WebKit says nope, check document.webkitFullscreenElement. Then Gecko comes along and is like psshh, nope. Use document.mozFullScreenElement instead. Notice the subtle capital S. Mozilla is the only browser that capitalizes screen in fullscreen. This is utter madness. Hopefully everyone will sort this out soon. I would prefer a nice simple API like most sane people and not have to use a giant if statement for each thing. Yes there are ways to clean it up. You can just make a function that hides it or assign the document function to the browser specific one, but still.

In the end, I didn't bother messing with anything except Chrome for the rest of my fullscreen implementation. My final version looks like this:

fullscreen_btn.addEventListener('click', () => {
    if (document.webkitFullscreenElement) {

    if (player.requestFullscreen) {
    } else if (player.webkitRequestFullScreen) {
    } else if (player.mozRequestFullScreen) {
    } else if (player.msRequestFullScreen) {

I added a button to the control bar, I just had it display FS, and then linked it to the above function. Actually going to fullscreen I wrote out the full if statement but for detecting and actually exiting fullscreen mode, I only use the webkit prefix. The only issue I ran into is my video player has a weird border when in fullscreen. I'm not sure if I used the wrong element or if there's something I could do in the styles to remove it. By this point I was just happy to have something fullscreen so didn't spend any time finding a solution. Over all I feel it went well.

Final Thoughts

The use of media on the web will only increase going forward. Being able to manipulate and control it well can mean the difference between a repeat or one-time user. As web developers we want to create an immersive and pleasant experience for our users so they feel comfortable and want to come back. Creating a well styled, feature rich media player is one step towards that goal.

One last thing. Always turnoff autoplay on video and audio unless the user is expecting it.

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