javascript - Chrome.webrequest.onBeforeRequest 多次调用自身

Question

我正在使用 JavaScript API 开发一个 Chrome 扩展程序，其中我尝试在 URL 与 Web 请求 URL 模式匹配时重定向该 URL

how chrome.webrequest.onebforerequest calling itsself multiple times

backgorund.js

        chrome.webRequest.onBeforeRequest.addListener(
            function(details) {
                var host="https://api.answerme.com/2.2/questions/345797";
                var x = new XMLHttpRequest();
                x.open('GET',host,false);

                x.onload = function() {
                // this function gives me URL and store into "redirectAnswerUrl" global variable (working fine)
                setRedirectedToAnswer(x.responseText);
                };      
                x.send();
         //this working fine output:-www.answerme.com/quetion/78784#45545
         alert("redirectAnswerUrl"+redirectAnswerUrl);
                if(redirectAnswerUrl!=""){
                  //but this redirectAnswerUrl has same pattern of default urls that is above output and manifest url  
                 return {redirectUrl: redirectAnswerUrl}
                }

            },
            {
                 //setting url which we gonna match during first load 
                 urls: [
                    "*://answerme.com/questions/*",
                    "*://www.answerme.com/questions/*"
                 ]
            },
            ["blocking"]
        );

ma​​nifest.json

{
    "name": "Demo",
    "description": "Demo",
    "version": "0.1",
    "manifest_version": 2,
    "browser_action": {
        "default_icon": "logo.png",
        "default_popup": "window.html"
    },
    "background": {
        "scripts": ["background.js"]
    },
    "permissions": [
        "activeTab", "tabs", "webRequest",
        "*://answerme.com/questions/*",
        "*://www.answerme.com/questions/*"
        "webRequestBlocking", "storage"
    ],
    "icons": {
        "16": "logo.png",
        "128": "logo.png"
    }
}

问题:在 Web 请求上检查的相同 URL 模式(即 API 输出 URL)具有“www.answerme.com/quetion/78878#787878”和 Web 请求 URL有“www.answerme.com/quetion/searchquery”

在这种情况下，当我们获取 www.answerme.com/questions/searchquery 时，页面将重定向到 http://www.answerme.com/questions/7847859# 748555，但问题是:我用来检查 URL 的模式有 * 来指示 URL 可以以任何协议(protocol)开头，并且其第一个属性以 quetions 开头>。这与重定向 URL http://www.answerme.com/questions/7847859#7848488 匹配，因此会陷入僵局(重复重定向)。我再次收到相同的 URL 模式请求(redirect url= www.asswerme.com/quetion/7878#7878 并且 list 文件上的 webrequest url 有 www.asswerme.com/quetion/*)，因此我决定检查 URL 是否以数字结尾(网络请求 list )，以便我可以轻松地将它们重定向到 http://www.answerme.com/questions/7847859#14524，而无需任何歧义。

Answer 1

您可以使用RegExp检查details.url是否仅以数字字符结尾

if (!/^\d+$/.test(details.url.split("/").pop())) {
  // `details.url` does not end with only digits, do other stuff
} else {
  return {redirectUrl: "http://www.example.com/add/7847859"}
}