EditContext: text property

A string containing the current editable content of the element that's attached to the EditContext object. Its initial value is the empty string.

This string may or may not be equal to the value of the textContent property of the DOM element that's associated to the EditContext. The associated element might, for example, be a <canvas> element, which doesn't have a textContent property. Or, the associated element might be a <div> element that contains text that's different than the EditContext.text value, for more advanced rendering.

The text property of the EditContext object can be used as the model for the editable text region. Other properties of the EditContext object, such as selectionStart and selectionEnd refer to offsets within the text string.

In the following example, the EditContext API is used to render the text a user enters in a <canvas> element.

<canvas id="editor-canvas"></canvas>

const canvas = document.getElementById("editor-canvas");
const ctx = canvas.getContext("2d");
const editContext = new EditContext();
canvas.editContext = editContext;

editContext.addEventListener("textupdate", (e) => {
  // When the user has focus on the <canvas> and enters text,
  // this event is fired, and we use it to re-render the text.
  console.log(
    `The user entered the text: ${e.text}. Re-rendering the full EditContext text`,
  );
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.fillText(editContext.text, 10, 10);
});