0

The userscript in question: http://userscripts.org/scripts/show/130532

After the site it's been made for has been updated to HTML5, I had to update the script. However, it's got a really big problem now. When I launch the script's main function that contains the XMLHttpRequest, it simply spams the console with these requests until the browser simply crashes.

Now, I looked around in both StackOverflow and in Google for anything that could help me, but there's nothing.

If you proceed to try the script, be careful, because it crashes the browser. Or at least, it does for me in FF 11.00

Code:

// ==UserScript==
// @name           Where my thread at
// @include        *//boards.4chan.org/*/res/*
// ==/UserScript==

(function () {
    "use strict";
    var board = document.location.href.match(/https?:\/\/boards\.4chan\.org\/[\w]+/i), threadNo = location.pathname.match(/\/res\/([\d]+)/i), main = document.getElementsByName("delform")[0], is404 = 0, ttt = null, b, c, num, timer, html, i, l, no, found, xhr1, xhr2, cstatus, ui, pg;

    function lookup(resp) {
        html = resp.match(/<div class="postContainer opContainer".*?<\/div>[^<]*?<\/div>/gi);
        if (html) {
            l = html.length;
            for (i = 0; i < l; i += i) {
                no = html[i].match(/<a href="res\/([\d]+)"/i)[1];
                if (threadNo[1] === no) {
                    document.getElementById('page').innerHTML = pg;
                    cstatus.innerHTML = "Status:&nbsp;Done";
                    found = 1;
                    break;
                }
            }
        }
    }

    function doIndex(pg) {
        b = document.getElementById('shouldi');
        if (!is404 && b.checked === true) {
            cstatus.innerHTML = "Status:&nbsp;Searching";
            c = document.getElementById('timerbox');
            num = parseInt(c.value, 10);
            if (num > 600) { timer = 600; }
            if (num < 30) { timer = 30; }
            if (isNaN(num)) {
                timer = 60;
                alert("Value entered is not a valid number! Defaulting to 60");
                c.value = "60";
            }
            if (!timer) { timer = num; }
            xhr1 = new XMLHttpRequest();
            xhr1.open("GET", board[0] + (0 === pg ? "" : "/" + pg), true);
            xhr1.setRequestHeader("Cache-Control", "no-cache");
            xhr1.onreadystatechange = function () {
                if (xhr1.readyState === 4) {
                    if (xhr1.status === 200) {
                        lookup(xhr1.responseText);
                    }
                }
                if (found) {
                    ttt = setTimeout(function () {
                        doIndex(0);
                    }, timer * 1000);
                } else {
                    if (pg < 15) {
                        doIndex(pg + 1);
                    } else {
                        cstatus.innerHTML = "Status:&nbsp;Really 404?";
                        xhr2 = new XMLHttpRequest();
                        xhr2.open("GET", board[0] + threadNo[0], true);
                        xhr2.setRequestHeader("Cache-Control", "no-cache");
                        xhr2.onreadystatechange = function () {
                            if (xhr2.readyState === 4) {
                                if (xhr2.status === 404) {
                                    cstatus.parentNode.removeChild(cstatus);
                                    document.getElementById('page').innerHTML = "404'd";
                                    is404 = 1;
                                } else {
                                    cstatus.innerHTML = "Status:&nbsp;Still alive";
                                    setTimeout(function () {
                                        doIndex(0);
                                    }, 1000);
                                }
                            }
                        };
                        xhr2.send(null);
                    }
                }
            };
            xhr1.send(null);
        }
    }

    ui = document.createElement('center');
    ui.innerHTML = '<table border="0" style="width: 100%"><tbody><tr><td style="width: 33%;text-align: right;">Timer(600-30s):&nbsp;<input type="text" value="30" maxlength="3" size="3" id="timerbox">&nbsp;&nbsp;</td><td style="width: 33%">&nbsp;<center><font size="20" color="red" id="page">&nbsp;</font></center>&nbsp;</td><td style="width: 33%;text-align:left;">&nbsp;&nbsp;<span id="checkcheck"><label for="shouldi">Checking</label><input type="checkbox" id="shouldi" /></span>&nbsp;&nbsp;<span id="checkstatus">Status:&nbsp;</span></td></tr></tbody></table>';
    main.parentNode.insertBefore(ui, main);
    cstatus = document.getElementById('checkstatus');
    cstatus.innerHTML = "Status:&nbsp;Ready";
    document.getElementById('checkcheck').addEventListener("click", function () {
        if (ttt !== null) {
            clearTimeout(ttt);
            ttt = null;
        }
        setTimeout(function () {
            doIndex(0);
        }, 500);
    }, false);
}());
4

2 回答 2

5

您正在使用多个变量而没有在本地声明这些变量：

var ..., found, xhr1, xhr2, cstatus, ui, pg;
...
function doIndex(pg) {
    ...
        xhr1 = new XMLHttpRequest();
     // ^^^^ No var !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
        ...
        xhr1.onreadystatechange = function() {
            if (xhr1.readyState === 4) { ... }
            if (found) {
                ...
            } else {
                if (pg < 15) {
                    doIndex(pg + 1); // <-- !!!!!!!!!!!!!!!!!!
                } else { ...
                    xhr2 = new XMLHttpRequest();
                    ...
                    xhr2.onreadystatechange = function() { ... };
                    xhr2.send(null);
                }
            }
        };
        xhr1.send(null);
    }
}  ...
doIndex(0); // Initiate the doom

首先，您将一个新的 XHR 实例分配给一个非局部xhr1变量。
然后，添加一个readystatechange事件处理程序，其中会发生以下情况：

  1. 最初，readyState不是四，所以found是假的。由于pg从 0 开始，doIndex(pg + 1)因此被调用。现在，xhr1被一个新的 XHR 实例覆盖。
  2. 这继续，直到pg达到 15。然后，pg < 15是错误的，恐怖开始了：
    • xhr1.onreadystatechange在请求期间多次触发。pg < 15是假的，所以else块被评估，你在其中启动了几个新的 XHR ( xhr2) 请求......
    • 所有之前的 readystatechange 事件仍然被触发，因为请求还没有完成。在每个事件处理程序中，您都在比较 的值xhr1.readyState，它指的是最后创建的xhr1请求的状态。
      因此，您doIndex(pg+1)一遍又一遍地调用，一旦pg达到 15，就会创建新的 XHR ( xhr2) 实例。

要解决此问题，请在函数中声明变量，并将整个onreadystatechange块包装在if (xhr1.readyState == 4)（或使用onload代替onreadystatechange）中。

function dIndex(pg) {
    var xhr1, xhr2;
    ...
    xhr1.onreadystatechange = function() {
        if (xhr1.readyState === 4) {
           /* ... */
        }
    };
    ...
于 2012-06-17T09:29:50.427 回答
0

这有助于基于答案：

                    let signupRequest = new XMLHttpRequest();
                    let url = "signup/" + inputMobile.value;
                    signupRequest.open("GET", url, true);
                    signupRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
                    signupRequest.send();

                    signupRequest.onreadystatechange = function () {
                        if (signupRequest.readyState === 4) {
                            hideLoading();
                            if (signupRequest.status === 200) {
                                console.log("OK: " + status + " --- " + signupRequest.response);
                            } else {
                                console.log("NOK: " + status + " --- " + signupRequest.response);
                            }
                        }
                    };
于 2019-08-05T04:36:58.723 回答