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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";
/**
* For imported stylesheets, `ownerNode` is null.
*
* To resolve the ownerNode for an imported stylesheet, loop on `parentStylesheet`
* until we reach the topmost stylesheet, which should have a valid ownerNode.
*
* Constructable stylesheets do not have an owner node and this method will
* return null.
*
* @param {StyleSheet}
* The stylesheet for which we want to retrieve the ownerNode.
* @return {DOMNode|null} The ownerNode or null for constructable stylesheets.
*/
function getStyleSheetOwnerNode(sheet) {
// If this is not an imported stylesheet and we have an ownerNode available
// bail out immediately.
if (sheet.ownerNode) {
return sheet.ownerNode;
}
let parentStyleSheet = sheet;
while (
parentStyleSheet.parentStyleSheet &&
parentStyleSheet !== parentStyleSheet.parentStyleSheet
) {
parentStyleSheet = parentStyleSheet.parentStyleSheet;
}
return parentStyleSheet.ownerNode;
}
exports.getStyleSheetOwnerNode = getStyleSheetOwnerNode;
/**
* Get the text of a stylesheet.
*
* TODO: A call site in window-global.js expects this method to return a promise
* so it is mandatory to keep it as an async function even if we are not using
*
* @param {StyleSheet}
* The stylesheet for which we want to retrieve the text.
* @returns {Promise}
*/
async function getStyleSheetText(styleSheet) {
if (!styleSheet.href) {
if (styleSheet.ownerNode) {
// this is an inline <style> sheet
return styleSheet.ownerNode.textContent;
}
// Constructed stylesheet.
return "";
}
return fetchStyleSheetText(styleSheet);
}
exports.getStyleSheetText = getStyleSheetText;
/**
* Retrieve the content of a given stylesheet
*
* @param {StyleSheet} styleSheet
* @returns {String}
*/
async function fetchStyleSheetText(styleSheet) {
const href = styleSheet.href;
const options = {
loadFromCache: true,
policy: Ci.nsIContentPolicy.TYPE_INTERNAL_STYLESHEET,
charset: getCSSCharset(styleSheet),
headers: {
accept: "text/css,*/*;q=0.1",
},
};
// stylesheets instead of the content principal since such stylesheets
// require system principal to load. At meanwhile, we strip the loadGroup
// for preventing the assertion of the userContextId mismatching.
// chrome|file|resource|moz-extension protocols rely on the system principal.
const excludedProtocolsRe = /^(chrome|file|resource|moz-extension):\/\//;
if (!excludedProtocolsRe.test(href)) {
// Stylesheets using other protocols should use the content principal.
const ownerNode = getStyleSheetOwnerNode(styleSheet);
if (ownerNode) {
// eslint-disable-next-line mozilla/use-ownerGlobal
options.window = ownerNode.ownerDocument.defaultView;
options.principal = ownerNode.ownerDocument.nodePrincipal;
}
}
let result;
try {
result = await fetch(href, options);
if (result.contentType !== "text/css") {
console.warn(
`stylesheets: fetch from cache returned non-css content-type ` +
`${result.contentType} for ${href}, trying without cache.`
);
options.loadFromCache = false;
result = await fetch(href, options);
}
} catch (e) {
// The list of excluded protocols can be missing some protocols, try to use the
// system principal if the first fetch failed.
console.error(
`stylesheets: fetch failed for ${href},` +
` using system principal instead.`
);
options.window = undefined;
options.principal = undefined;
result = await fetch(href, options);
}
return result.content;
}
/**
* Get charset of a given stylesheet
*
* @param {StyleSheet} styleSheet
* @returns {String}
*/
function getCSSCharset(styleSheet) {
if (styleSheet) {
// charset attribute of <link> or <style> element, if it exists
if (styleSheet.ownerNode?.getAttribute) {
const linkCharset = styleSheet.ownerNode.getAttribute("charset");
if (linkCharset != null) {
return linkCharset;
}
}
// charset of referring document.
if (styleSheet.ownerNode?.ownerDocument.characterSet) {
return styleSheet.ownerNode.ownerDocument.characterSet;
}
}
return "UTF-8";
}