Element: compositionstart event

The compositionstart event is fired when a text composition system such as an input method editor starts a new composition session.

For example, this event could be fired after a user starts entering a Chinese character using a Pinyin IME.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener('compositionstart', (event) => {});

oncompositionstart = (event) => { };

Event type

Event properties

This interface also inherits properties of its parent, UIEvent, and its ancestor — Event.

CompositionEvent.data Read only

Returns the characters generated by the input method that raised the event; its varies depending on the type of event that generated the CompositionEvent object.

CompositionEvent.locale Read only Deprecated

Returns the locale of current input method (for example, the keyboard layout locale if the composition is associated with IME).

Examples

const inputElement = document.querySelector('input[type="text"]');

inputElement.addEventListener('compositionstart', (event) => {
  console.log(`generated characters were: ${event.data}`);
});

Live example

HTML

<div class="control">
  <label for="name">First select textbox, then to open IME:<ul><li>on macOS type <kbd>option</kbd> + <kbd>`</kbd></li><li>on Windows type <kbd>windows</kbd> + <kbd>.</kbd></li></ul></label>
  <input type="text" id="example" name="example">
</div>

<div class="event-log">
  <label for="eventLog">Event log:</label>
  <textarea readonly class="event-log-contents" rows="8" cols="25" id="eventLog"></textarea>
  <button class="clear-log">Clear</button>
</div>

JS

const inputElement = document.querySelector('input[type="text"]');
const log = document.querySelector('.event-log-contents');
const clearLog = document.querySelector('.clear-log');

clearLog.addEventListener('click', () => {
    log.textContent = '';
});

function handleEvent(event) {
    log.textContent += `${event.type}: ${event.data}\n`;
}

inputElement.addEventListener('compositionstart', handleEvent);
inputElement.addEventListener('compositionupdate', handleEvent);
inputElement.addEventListener('compositionend', handleEvent);

Result

Specifications

Specification
UI Events
# event-type-compositionstart

Browser compatibility

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See also