event.key = Unidentified, event.keyCode = 229

Happy new year

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feature or a bug? Maybe it’s a bug.

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What is the current behavior? I’m a Chinese developer, our character looks like 你 好,. To input those characters, we have a program to process combinations of the single key down. For example, I want to input 你, I will input a combination of keys ni, and then select the character 你 from the program. In the browser environment this cannot be seen(if I’m inputting in an input DOM, the value of it will not be changed until the last step).

I simplified the problem and put it on the codesandbox code

I just listen to the input’s ‘keydown’ event through the onKeyDown and print what key I’ve pressed. In chrome, the key is Unidentified, keyCode is 229, In firefox key is Process. ONLY a-zA-z0-9 behave unusual, keys like ctrl, shift work fine.

My input program has two modes, one is English, another is Chinese. And I find that if I turn my input program on, no matter what mode it is, my code works weird as above. If I turn the input program off, my code works fine. In my view, with the input program on and set it to English mode, has no differences with turn it off

I also tried add listener on a normal html page like

window.addEventListener('keydown', function(e) {console.log(e.key, e.keyCode)})

This works fine with my input program on.

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versions

OS: Ubuntu 18.04 with the latest update Input program: Ibus-libpinyin(github) Browser: Chrome 71.0.3578.98, Firefox 64.0 React: 16.7.0

[Jessidhia]

That is how the key event API works, anything written while the IME is active will have keyCode = 229.

You have to use the input events (onChange in React terms), and also check if their isComposing property is true. I don’t think React’s synthetic event has all the relevant properties so you probably need to work with the nativeEvent.

[joshxyzhimself]

IME here means Input-Method Editor.

When using virtual/mobile keyboards, formally known as IME (Input-Method Editor), the W3C standard states that a KeyboardEvent’s e.keyCode should be 229 and e.key should be “Unidentified”.

While some of these keyboards might still use the right values for e.key, e.code, e.keyCode… when pressing certain keys such as arrows or backspace, there’s no guarantee, so your keyboard logic might not always work on mobile devices.

Check here for more info: https://javascript.info/keyboard-events#mobile-keyboards