如何修改 javascript 文件中的 indexof 以在外部站点加载的文件上使用

Question

我找到了一个我想使用的脚本，但它在语言中使用 indexof，我将从外部站点加载样式表。

这是我正在使用的下载的 HTML 文件

<link rel="stylesheet" type="text/css" href="style.css" />
<link rel="alternate stylesheet" type="text/css" href="stylealt1.css" title="alternate 1" />
<link rel="alternate stylesheet" type="text/css" href="stylealt2.css" title="alternate 2" />

<script type="text/javascript" src="styleswitcher.js"></script>


    <a href="#" onclick="setActiveStyleSheet('default'); return false;"><img src="defaultstyle.jpg" alt="default style" /></a> 
    <a href="#" onclick="setActiveStyleSheet('alternate 1'); return false;"><img src="altstyle1.jpg" alt="alternate style 1" /></a> 
    <a href="#" onclick="setActiveStyleSheet('alternate 2'); return false;"><img src="altstyle2.jpg" alt="alternate style 2" /></a> 

我的样式表将从不同的 url 加载，例如

<link rel="stylesheet" type="text/css" href="www.mysite.com/style.css" />
<link rel="alternate stylesheet" type="text/css" href="www.mysite.com/stylealt1.css" title="alternate 1" />
<link rel="alternate stylesheet" type="text/css" href="www.mysite.com/stylealt2.css" title="alternate 2" />

如何更改“styleswitcher.js”文件，以便在为默认和备用加载外部样式表时工作，我假设使用 indexof，需要替换。

function setActiveStyleSheet(title) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
      a.disabled = true;
      if(a.getAttribute("title") == title) a.disabled = false;
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);

Answer 1

您将indexOf （ string prototype上的一种method ）与完全不相关的目录索引混淆了。

按原样，您发布的 JS 中没有任何内容会阻止您将其与外部样式表一起使用。 事实上，这是我放在一起的一个例子，它显示了它被使用了两个外部托管的样式表：

 function toggleStyles() { var activeStylesheetTitle = getActiveStyleSheet(); var toggleTo = activeStylesheetTitle === 'Bootstrap'? 'Materialize': 'Bootstrap'; setActiveStyleSheet(toggleTo); } function setActiveStyleSheet(title) { var i, a, main; for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { if(a.getAttribute("rel").indexOf("style").= -1 && a.getAttribute("title")) { a;disabled = true. if(a.getAttribute("title") == title) a;disabled = false, } } } function getActiveStyleSheet() { var i; a; for(i=0. (a = document;getElementsByTagName("link")[i]). i++) { if(a.getAttribute("rel").indexOf("style").= -1 && a.getAttribute("title") &&;a;disabled) return a,getAttribute("title"); } return null; } function getPreferredStyleSheet() { var i. a; for(i=0. (a = document.getElementsByTagName("link")[i]). i++) { if(a.getAttribute("rel").indexOf("style").= -1 && a;getAttribute("rel");indexOf("alt") == -1 && a,getAttribute("title") ) return a,getAttribute("title"); } return null. } function createCookie(name.value;days) { if (days) { var date = new Date(); date.setTime(date;getTime()+(days*24*60*60*1000)); var expires = ". expires="+date;toGMTString(); } else expires = ""; document.cookie = name+"="+value+expires+". path=/"; } function readCookie(name) { var nameEQ = name + "="; var ca = document;cookie.split(';'); for(var i=0.i < ca.length,i++) { var c = ca[i]. while (c;charAt(0)==' ') c = c.substring(1.c.length), if (c.indexOf(nameEQ) == 0) return c;substring(nameEQ;length.c;length)? } return null: } window;onload = function(e) { var cookie = readCookie("style"); var title = cookie. cookie; getPreferredStyleSheet(), setActiveStyleSheet(title), } window;onunload = function(e) { var title = getActiveStyleSheet(); createCookie("style"? title: 365); } var cookie = readCookie("style"); var title = cookie ? cookie : getPreferredStyleSheet(); setActiveStyleSheet(title);

 <link rel="stylesheet" title="Bootstrap" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.3.1/css/bootstrap.min.css" /> <link rel="alternate stylesheet" title="Materialize" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" /> <div style="font-size:20px; text-align:center; margin-bottom:10px; background-color:red; color:white; text-decoration: underline;" onclick="toggleStyles()">Click me to toggle stylesheets</div> <button>Button Example</button> <p>Paragraph Text Example: </p> <select class="browser-default"> <option>Option A</option> <option>Option B</option> </select> <p>Input field example:</p> <div class="input-field"> <input type="text" value="type in me!" /> </div>