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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
/**
* Get the text of the element parameter, as provided by the Selection API. We need to
* rely on the Selection API as it mimics exactly what the user would have if they do a
* selection using the mouse and copy it. `HTMLElement.textContent` and
* `HTMLElement.innerText` follow a different codepath than user selection + copy.
* They both have issues when dealing with whitespaces, and therefore can't be used to
* have a reliable result.
*
* As the Selection API is exposed through the Window object, if we don't have a window
* we fallback to `HTMLElement.textContent`.
*
* @param {HTMLElement} el: The element we want the text of.
* @returns {String|null} The text of the element, or null if el is falsy.
*/
function getElementText(el) {
if (!el) {
return null;
}
// If we can, we use the Selection API to match what the user would get if they
// manually select and copy the message.
const doc = el.ownerDocument;
const win = doc && doc.defaultView;
if (!win) {
return el.textContent;
}
// We store the current selected range and unselect everything.
const selection = win.getSelection();
const currentSelectedRange =
!selection.isCollapsed && selection.getRangeAt(0);
selection.removeAllRanges();
// Then creates a range from `el`, and get the text content.
const range = doc.createRange();
range.selectNode(el);
selection.addRange(range);
const text = selection.toString();
// Finally we revert the selection to what it was.
selection.removeRange(range);
if (currentSelectedRange) {
selection.addRange(currentSelectedRange);
}
return text;
}
module.exports = {
getElementText,
};