stylus/background/style-via-xhr.js

86 lines
2.6 KiB
JavaScript

/* global API CHROME prefs */
'use strict';
// eslint-disable-next-line no-unused-expressions
CHROME && (async () => {
const prefId = 'styleViaXhr';
const blobUrlPrefix = 'blob:' + chrome.runtime.getURL('/');
const stylesToPass = {};
await prefs.initializing;
toggle(prefId, prefs.get(prefId));
prefs.subscribe([prefId], toggle);
function toggle(key, value) {
if (!chrome.declarativeContent) { // not yet granted in options page
value = false;
}
if (value) {
const reqFilter = {
urls: ['<all_urls>'],
types: ['main_frame', 'sub_frame'],
};
chrome.webRequest.onBeforeRequest.addListener(prepareStyles, reqFilter);
chrome.webRequest.onHeadersReceived.addListener(passStyles, reqFilter, [
'blocking',
'responseHeaders',
chrome.webRequest.OnHeadersReceivedOptions.EXTRA_HEADERS,
].filter(Boolean));
} else {
chrome.webRequest.onBeforeRequest.removeListener(prepareStyles);
chrome.webRequest.onHeadersReceived.removeListener(passStyles);
}
if (!chrome.declarativeContent) {
return;
}
chrome.declarativeContent.onPageChanged.removeRules([prefId], async () => {
if (!value) return;
chrome.declarativeContent.onPageChanged.addRules([{
id: prefId,
conditions: [
new chrome.declarativeContent.PageStateMatcher({
pageUrl: {urlContains: ':'},
}),
],
actions: [
new chrome.declarativeContent.RequestContentScript({
allFrames: true,
// This runs earlier than document_start
js: chrome.runtime.getManifest().content_scripts[0].js,
}),
],
}]);
});
}
/** @param {chrome.webRequest.WebRequestBodyDetails} req */
function prepareStyles(req) {
API.getSectionsByUrl(req.url).then(sections => {
const str = JSON.stringify(sections);
if (str !== '{}') {
stylesToPass[req.requestId] = URL.createObjectURL(new Blob([str])).slice(blobUrlPrefix.length);
setTimeout(cleanUp, 600e3, req.requestId);
}
});
}
/** @param {chrome.webRequest.WebResponseHeadersDetails} req */
function passStyles(req) {
const blobId = stylesToPass[req.requestId];
if (blobId) {
const {responseHeaders} = req;
responseHeaders.push({
name: 'Set-Cookie',
value: `${chrome.runtime.id}=${prefs.get('disableAll') ? 1 : 0}${blobId}`,
});
return {responseHeaders};
}
}
function cleanUp(key) {
const blobId = stylesToPass[key];
delete stylesToPass[key];
if (blobId) URL.revokeObjectURL(blobUrlPrefix + blobId);
}
})();