EditContext: compositionstart event

Limited availability

The compositionstart event of the EditContext interface fires when composition using an Input Method Editor (IME) window starts.

Syntax

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

addEventListener("compositionstart", (event) => { })

oncompositionstart = (event) => { }

Examples

Using compositionstart to change the editable region’s border

In the following example, the editable region’s border is set to red when the compositionstart event fires, and back to black when the compositionend event fires. Note that the event listener callbacks in this example are only called when using an IME window, or other platform-specific editing UI surfaces, to compose text.

#text-editor {
  border: 1px solid black;
}
#text-editor.is-composing {
  border-color: red;
}

<div id="text-editor"></div>

const editorElement = document.getElementById("text-editor");
const editContext = new EditContext();
editorElement.editContext = editContext;

editContext.addEventListener("compositionstart", (event) => {
  editorElement.classList.add("is-composing");
});

editContext.addEventListener("compositionend", (event) => {
  editorElement.classList.remove("is-composing");
});

Specifications

Browser compatibility