ajax hook
Ekde
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greatest.deepsurf.us/scripts/455943/1124435/ajaxHooker.js
// ==UserScript==
// @name ajaxHooker
// @author cxxjackie
// @version 1.1.1
// @supportURL https://bbs.tampermonkey.net.cn/thread-3284-1-1.html
// ==/UserScript==
var ajaxHooker = function() {
const win = window.unsafeWindow || document.defaultView || window;
const hookFns = [];
const xhrProto = win.XMLHttpRequest.prototype;
const xhrProtoDesc = Object.getOwnPropertyDescriptors(xhrProto);
const xhrReadyState = xhrProtoDesc.readyState.get;
const resProto = win.Response.prototype;
const realXhrOpen = xhrProto.open;
const realXhrSend = xhrProto.send;
const realFetch = win.fetch;
const xhrResponses = ['response', 'responseText', 'responseXML'];
const fetchResponses = ['arrayBuffer', 'blob', 'formData', 'json', 'text'];
function emptyFn() {}
function readOnly(obj, prop, value = obj[prop]) {
Object.defineProperty(obj, prop, {
configurable: true,
enumerable: true,
get: () => value,
set: emptyFn
});
}
function writable(obj, prop, value = obj[prop]) {
Object.defineProperty(obj, prop, {
configurable: true,
enumerable: true,
writable: true,
value: value
});
}
function fakeXhrOpen(method, url, ...args) {
const xhr = this;
xhr.__ajaxHooker = xhr.__ajaxHooker || {headers: {}};
xhr.__ajaxHooker.url = url;
xhr.__ajaxHooker.method = method.toUpperCase();
xhr.__ajaxHooker.remainArgs = args;
xhr.setRequestHeader = (header, value) => {
xhr.__ajaxHooker.headers[header] = value;
}
xhrResponses.forEach(prop => {
delete xhr[prop]; // delete descriptor
});
return realXhrOpen.call(xhr, method, url, ...args);
}
function fakeXhrSend(data) {
const xhr = this;
const req = xhr.__ajaxHooker;
if (xhrReadyState.call(xhr) === 1 && req) {
const request = {
type: 'xhr',
url: req.url,
method: req.method,
abort: false,
headers: req.headers,
data: data,
response: null
};
for (const fn of hookFns) {
fn(request);
if (request.abort) return;
}
realXhrOpen.call(xhr, request.method, request.url, ...req.remainArgs);
data = request.data;
for (const header in request.headers) {
xhrProto.setRequestHeader.call(xhr, header, request.headers[header]);
}
if (typeof request.response === 'function') {
const arg = {};
xhrResponses.forEach(prop => {
Object.defineProperty(xhr, prop, {
configurable: true,
enumerable: true,
get: () => {
if (xhrReadyState.call(xhr) === 4) {
if (!('finalUrl' in arg)) {
arg.finalUrl = xhr.responseURL;
arg.status = xhr.status;
arg.responseHeaders = {};
const arr = xhr.getAllResponseHeaders().trim().split(/[\r\n]+/);
for (const line of arr) {
const parts = line.split(/:\s*/);
if (parts.length === 2) {
const lheader = parts[0].toLowerCase();
if (lheader in arg.responseHeaders) {
arg.responseHeaders[lheader] += ', ' + parts[1];
} else {
arg.responseHeaders[lheader] = parts[1];
}
}
}
}
if (!(prop in arg)) {
arg[prop] = xhrProtoDesc[prop].get.call(xhr);
request.response(arg);
}
}
return prop in arg ? arg[prop] : xhrProtoDesc[prop].get.call(xhr);
}
});
});
}
}
return realXhrSend.call(xhr, data);
}
function hookFetchResponse(response, arg, callback) {
fetchResponses.forEach(prop => {
response[prop] = () => new Promise((resolve, reject) => {
resProto[prop].call(response).then(res => {
if (!(prop in arg)) {
arg[prop] = res;
callback(arg);
}
resolve(prop in arg ? arg[prop] : res);
}, reject);
});
});
}
function fakeFetch(url, init) {
if (typeof url === 'string' || url instanceof String) {
init = init || {};
init.headers = init.headers || {};
const request = {
type: 'fetch',
url: url,
method: (init.method || 'GET').toUpperCase(),
abort: false,
headers: {},
data: init.body,
response: null
};
if (init.headers.toString() === '[object Headers]') {
for (const [key, val] of init.headers) {
request.headers[key] = val;
}
} else {
request.headers = {...init.headers};
}
for (const fn of hookFns) {
fn(request);
if (request.abort) return Promise.reject('aborted');
}
url = request.url;
init.method = request.method;
init.headers = request.headers;
init.body = request.data;
if (typeof request.response === 'function') {
return new Promise((resolve, reject) => {
realFetch.call(win, url, init).then(response => {
const arg = {
finalUrl: response.url,
status: response.status,
responseHeaders: {}
};
for (const [key, val] of response.headers) {
arg.responseHeaders[key] = val;
}
hookFetchResponse(response, arg, request.response);
response.clone = () => {
const resClone = resProto.clone.call(response);
hookFetchResponse(resClone, arg, request.response);
return resClone;
};
resolve(response);
}, reject);
});
}
}
return realFetch.call(win, url, init);
}
xhrProto.open = fakeXhrOpen;
xhrProto.send = fakeXhrSend;
win.fetch = fakeFetch;
return {
hook: fn => hookFns.push(fn),
protect: () => {
readOnly(win, 'XMLHttpRequest');
readOnly(xhrProto, 'open');
readOnly(xhrProto, 'send');
readOnly(win, 'fetch');
},
unhook: () => {
writable(win, 'XMLHttpRequest');
writable(xhrProto, 'open', realXhrOpen);
writable(xhrProto, 'send', realXhrSend);
writable(win, 'fetch', realFetch);
}
};
}();