我能想到的有两种可能的方法:
1 - 使用计时器检查您的脚本是否仍然存在,如果不存在,请重新添加...
2 - 检查 ajax 调用,如果它们的 url 与删除脚本的 url 之一匹配,请再次添加脚本。
您的脚本(清单中定义的脚本)仍然存在,即使在 ajax 调用之后,它也不会再次运行(不确定历史推送器会发生什么)。因此,我假设您需要重新添加一些元素或重新运行剥离。我假设您添加了附加 html 标签的脚本。
因此,您需要的是读取元素或重新运行特定代码的东西。
1 - 计时器方法 - 我创建了一个解决方案任何元素(不仅仅是脚本)我希望添加到某个目标元素在一个页面中。
它使用计时器来检查目标元素是否存在。
当它找到目标元素时,它会添加我的。然后调整计时器来检查我的元素是否仍然存在。如果没有,请重新添加。
你只需要打电话appendChildPersistent
一次,这将在您导航的整个过程中保持活动状态。
var timers = {}; //stores the setInterval ids
//this is the only method you need to call
//give your script an `id` (1)
//the child is your script, it can be anything JQuery.append can take
//toElem is the Jquery "SELECTOR" of the element to add your script into.
//I'm not sure what would happen if toElem were not a string.
//callback is a function to call after insertion if desired, optional.
appendChildPersistent = function(id, child, toElem, callback)
{
//wait for target element to appear
withLateElement(toElem, function(target)
{
target.append(child); //appends the element - your script
if (typeof callback !== 'undefined') callback(); //execute callback if any
//create a timer to constantly check if your script is still there
timers[id] = setInterval(function()
{
//if your script is not found, clear this timer and tries to add again
if (document.getElementById(id) === null)
{
clearInterval(timers[id]);
delete timers[id];
appendChildPersistent(id, child, toElem, callback);
}
},3000);
});
}
//this function waits for an element to appear on the page
//since you can't foresee when an ajax call will finish
//selector is the jquery selector of the target element
//doAction is what to do when the element is found
function withLateElement(selector, doAction)
{
//checks to see if this element is already being waited for
if (!(selector in timers))
{
//create a timer to check if the target element appeared
timers[selector] = setInterval(function(){
var elem = $(selector);
//checks if the element exists and is not undefined
if (elem.length >= 0)
{
if (typeof elem[0] !== 'undefined')
{
//stops searching for it and executes the action specified
clearInterval(timers[selector]);
delete timers[selector];
doAction(elem);
}
}
}, 2000);
}
}
(1) 看起来在脚本标签中添加Id没有问题:为脚本标签指定 ID
2 - 捕获ajax调用
一个选项是使用chrome.webRequest。但奇怪的是,这对我不起作用。另一种选择如下。
对于这种情况,请检查这个答案, and 别忘了阅读相关答案Chrome 扩展程序在那里。只有遵循整个过程,它才会起作用。幸运的是,我今天测试了它,效果很好:p
在这里,你要做的就是改变XMLHttpRequest
方法open
and send
检测(也可能获取参数)它们何时被调用。
但是,在 Google 扩展中,您绝对有必要将片段插入页面中(不是注入内容脚本的后台页面或脚本,而是注入一些代码的内容脚本进入大教堂,如下所示)。
var script = document.createElement('script');
script.textContent = actualCode; //actual code is the code you want to inject, the one that replaces the ajax methods
document.head.appendChild(script); //make sure document.head is already loaded before doing it
script.parentNode.removeChild(script); //I'm not sure why the original answer linked removes the script after that, but I kept doing it in my solution
这一点至关重要,因为扩展程序试图创建一个隔离的环境,并且您对扩展程序所做的更改XMLHttpRequest
在这种环境下根本不会参加。 (这就是为什么 JQuery.ajaxComplete 似乎不起作用,您需要在页面中注入一个脚本才能使其工作 -看这里)
In 这个纯javascript解决方案,您替换方法:
//enclosing the function in parentheses to avoid conflict with vars from the page scope
(function() {
var XHR = XMLHttpRequest.prototype;
// Store the orignal methods from the request
var open = XHR.open;
var send = XHR.send;
// Create your own methods to replace those
//this custom open stores the method requested (get or post) and the url of the request
XHR.open = function(method, url) {
this._method = method; //this field was invented here
this._url = url; //this field was invented here
return open.apply(this, arguments); //calls the original method without any change
//what I did here was only to capture the method and the url information
};
//this custom send adds an event listener that fires whenever a request is complete/loaded
XHR.send = function(postData) {
//add event listener that fires when request loads
this.addEventListener('load', function() {
//what you want to do when a request is finished
//check if your element is there and readd it if necessary
//if you know the exact request url, you can put an if here, but it's not necessary
addMyElementsToPage(); //your custom function to add elements
console.log("The method called in this request was: " + this._method);
console.log("The url of this request was: " + this._url);
console.log("The data retrieved is: " + this.responseText);
});
//call the original send method without any change
//so the page can continue it's execution
return send.apply(this, arguments);
//what we did here was to insert an interceptor of the success of a request and let the request continue normally
};
})();