使用 JavaScript 将相对路径转换为绝对路径

最简单、最有效和最正确的方法是只使用 URL api。

new URL("http://www.stackoverflow.com?q=hello").href;
//=> "http://www.stackoverflow.com/?q=hello"
new URL("mypath","http://www.stackoverflow.com").href;
//=> "http://www.stackoverflow.com/mypath"
new URL("../mypath","http://www.stackoverflow.com/search").href
//=> "http://www.stackoverflow.com/mypath"
new URL("../mypath", document.baseURI).href
//=> "https://stackoverflow.com/questions/mypath"

在性能方面，此解决方案与使用字符串操作相当，并且比创建a标签快两倍。

Javascript会为你做。无需创建函数。

var link = document.createElement("a");
link.href = "../../lib/slider/slider.css";
alert(link.protocol+"//"+link.host+link.pathname+link.search+link.hash);
// Output will be "http://www.yoursite.com/lib/slider/slider.css"

但是，如果您需要将其作为函数：

var absolutePath = function(href) {
    var link = document.createElement("a");
    link.href = href;
    return (link.protocol+"//"+link.host+link.pathname+link.search+link.hash);
}

更新：如果您需要完整的绝对路径，则更简单的版本：

var absolutePath = function(href) {
    var link = document.createElement("a");
    link.href = href;
    return link.href;
}

这应该可以做到：

function absolute(base, relative) {
    var stack = base.split("/"),
        parts = relative.split("/");
    stack.pop(); // remove current file name (or empty string)
                 // (omit if "base" is the current folder without trailing slash)
    for (var i=0; i<parts.length; i++) {
        if (parts[i] == ".")
            continue;
        if (parts[i] == "..")
            stack.pop();
        else
            stack.push(parts[i]);
    }
    return stack.join("/");
}

这是来自 MDN 的牢不可破！

/*'
|*|
|*|  :: translate relative paths to absolute paths ::
|*|
|*|  https://developer.mozilla.org/en-US/docs/Web/API/document.cookie
|*|
|*|  The following code is released under the GNU Public License, version 3 or later.
|*|  http://www.gnu.org/licenses/gpl-3.0-standalone.html
|*|
'*/
function relPathToAbs (sRelPath) {
  var nUpLn, sDir = "", sPath = location.pathname.replace(/[^'/]*$/, sRelPath.replace(/('/|^)(?:'.?'/+)+/g, "$1"));
  for (var nEnd, nStart = 0; nEnd = sPath.indexOf("/../", nStart), nEnd > -1; nStart = nEnd + nUpLn) {
    nUpLn = /^'/(?:'.'.'/)*/.exec(sPath.slice(nEnd))[0].length;
    sDir = (sDir + sPath.substring(nStart, nEnd)).replace(new RegExp("(?:'''/+[^'''/]*){0," + ((nUpLn - 1) / 3) + "}$"), "/");
  }
  return sDir + sPath.substr(nStart);
}

示例用法：

/* Let us be in /en-US/docs/Web/API/document.cookie */
alert(location.pathname);
// displays: /en-US/docs/Web/API/document.cookie
alert(relPathToAbs("./"));
// displays: /en-US/docs/Web/API/
alert(relPathToAbs("../Guide/API/DOM/Storage"));
// displays: /en-US/docs/Web/Guide/API/DOM/Storage
alert(relPathToAbs("../../Firefox"));
// displays: /en-US/docs/Firefox
alert(relPathToAbs("../Guide/././API/../../../Firefox"));
// displays: /en-US/docs/Firefox

如果要对浏览器中自定义网页中的链接进行相对到绝对的转换(而不是运行脚本的页面(，则可以使用 @Bergi 建议的函数的更增强版本：

var resolveURL=function resolve(url, base){
    if('string'!==typeof url || !url){
        return null; // wrong or empty url
    }
    else if(url.match(/^[a-z]+':'/'//i)){ 
        return url; // url is absolute already 
    }
    else if(url.match(/^'/'//)){ 
        return 'http:'+url; // url is absolute already 
    }
    else if(url.match(/^[a-z]+':/i)){ 
        return url; // data URI, mailto:, tel:, etc.
    }
    else if('string'!==typeof base){
        var a=document.createElement('a'); 
        a.href=url; // try to resolve url without base  
        if(!a.pathname){ 
            return null; // url not valid 
        }
        return 'http://'+url;
    }
    else{ 
        base=resolve(base); // check base
        if(base===null){
            return null; // wrong base
        }
    }
    var a=document.createElement('a'); 
    a.href=base;
    if(url[0]==='/'){ 
        base=[]; // rooted path
    }
    else{ 
        base=a.pathname.split('/'); // relative path
        base.pop(); 
    }
    url=url.split('/');
    for(var i=0; i<url.length; ++i){
        if(url[i]==='.'){ // current directory
            continue;
        }
        if(url[i]==='..'){ // parent directory
            if('undefined'===typeof base.pop() || base.length===0){ 
                return null; // wrong url accessing non-existing parent directories
            }
        }
        else{ // child directory
            base.push(url[i]); 
        }
    }
    return a.protocol+'//'+a.hostname+base.join('/');
}

如果出现问题，它会返回null。

用法：

resolveURL('./some.css', 'http://example.com/stats/2012/'); 
// returns http://example.com/stats/2012/some.css
resolveURL('extra/some.css', 'http://example.com/stats/2012/');
// returns http://example.com/stats/2012/extra/some.css
resolveURL('../../lib/slider/slider.css', 'http://example.com/stats/2012/');
// returns http://example.com/lib/slider/slider.css
resolveURL('/rootFolder/some.css', 'https://example.com/stats/2012/');
// returns https://example.com/rootFolder/some.css
resolveURL('localhost');
// returns http://localhost
resolveURL('../non_existing_file', 'example.com')
// returns null

function canonicalize(url) {
    var div = document.createElement('div');
    div.innerHTML = "<a></a>";
    div.firstChild.href = url; // Ensures that the href is properly escaped
    div.innerHTML = div.innerHTML; // Run the current innerHTML back through the parser
    return div.firstChild.href;
}

这也适用于IE6，不像其他一些解决方案(请参阅从相对URL获取绝对URL。(IE6 问题((

建议和接受的解决方案不支持服务器相对 URL，并且不适用于绝对 URL。例如，如果我的亲戚是/sites/folder1，它将无法工作。

这是另一个支持完整，服务器相对或相对URL以及.的函数。/为一级以上。它并不完美，但涵盖了很多选择。当您的基本网址不是当前页面网址时，请使用此选项，否则有更好的替代方法。

    function relativeToAbsolute(base, relative) {
    //make sure base ends with /
    if (base[base.length - 1] != '/')
        base += '/';
    //base: https://server/relative/subfolder/
    //url: https://server
    let url = base.substr(0, base.indexOf('/', base.indexOf('//') + 2));
    //baseServerRelative: /relative/subfolder/
    let baseServerRelative = base.substr(base.indexOf('/', base.indexOf('//') + 2));
    if (relative.indexOf('/') === 0)//relative is server relative
        url += relative;
    else if (relative.indexOf("://") > 0)//relative is a full url, ignore base.
        url = relative;
    else {
        while (relative.indexOf('../') === 0) {
            //remove ../ from relative
            relative = relative.substring(3);
            //remove one part from baseServerRelative. /relative/subfolder/ -> /relative/
            if (baseServerRelative !== '/') {
                let lastPartIndex = baseServerRelative.lastIndexOf('/', baseServerRelative.length - 2);
                baseServerRelative = baseServerRelative.substring(0, lastPartIndex + 1);
            }
        }
        url += baseServerRelative + relative;//relative is a relative to base.
    }
    return url;
}

希望这有帮助。在 JavaScript 中没有这个基本实用程序真的很令人沮丧。

这是一个非常古老的问题，但你可以用： (new URL(relativePath, location)).href .

href 解决方案仅在加载文档后有效(至少在 IE11 中(。 这对我有用：

link = link || document.createElement("a");
link.href =  document.baseURI + "/../" + href;
return link.href;

见 https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base

我必须为接受的解决方案添加修复程序，因为我们可以在 angularjs 导航中的 # 后有斜杠。

function getAbsoluteUrl(base, relative) {
  // remove everything after #
  var hashPosition = base.indexOf('#');
  if (hashPosition > 0){
    base = base.slice(0, hashPosition);
  }
  // the rest of the function is taken from http://stackoverflow.com/a/14780463
  // http://stackoverflow.com/a/25833886 - this doesn't work in cordova
  // http://stackoverflow.com/a/14781678 - this doesn't work in cordova
  var stack = base.split("/"),
      parts = relative.split("/");
  stack.pop(); // remove current file name (or empty string)
               // (omit if "base" is the current folder without trailing slash)
  for (var i=0; i<parts.length; i++) {
    if (parts[i] == ".")
      continue;
    if (parts[i] == "..")
      stack.pop();
    else
      stack.push(parts[i]);
  }
  return stack.join("/");
}

这将起作用。 但仅当您打开带有其文件名的页面时。 当您打开这样的链接时，它将无法正常工作 stackoverflow.com/page . 它将适用于stackoverflow.com/page/index.php

function reltoabs(link){
    let absLink = location.href.split("/");
    let relLink = link;
    let slashesNum = link.match(/[.]{2}'//g) ? link.match(/[.]{2}'//g).length : 0;
    for(let i = 0; i < slashesNum + 1; i++){
        relLink = relLink.replace("../", "");
        absLink.pop();
    }
    absLink = absLink.join("/");
    absLink += "/" + relLink;
    return absLink;
}

我找到了一个非常简单的解决方案来做到这一点，同时仍然通过使用历史API(IE 10或更高版本(仍然支持IE 10(IE不支持URL-API(。此解决方案无需任何字符串操作即可工作。

function resolveUrl(relativePath) {
    var originalUrl = document.location.href;
    history.replaceState(history.state, '', relativePath);
    var resolvedUrl = document.location.href;
    history.replaceState(history.state, '', originalUrl);
    return resolvedUrl;
}

history.replaceState()不会触发浏览器导航，但仍会修改document.location并支持相对路径和绝对路径。

此解决方案的一个缺点是，如果您已经在使用历史记录 API 并使用标题设置了自定义状态，则当前状态的标题将丢失。

尝试：

/**
 * Convert relative paths to absolute paths
 * @author HaNdTriX
 * @param {string} html - HTML string
 * @param {string} baseUrl - base url to prepend to relative paths
 * @param  {string[]} [attributes] - attributes to convert
 * @returns {string}
 */
function absolutify(
  html,
  baseUrl,
  attributes = [
    "href",
    "src",
    "srcset",
    "cite",
    "background",
    "action",
    "formaction",
    "icon",
    "manifest",
    "code",
    "codebase",
  ]
) {
  // Build the regex to match the attributes.
  const regExp = new RegExp(
    `(?<attribute>${attributes.join(
      "|"
    )})=(?<quote>['"])(?<path>.*?)''k<quote>`,
    "gi"
  );
  return html.replaceAll(regExp, (...args) => {
    // Get the matched groupes
    const { attribute, quote, path } = args[args.length - 1];
    // srcset may have multiple paths `<url> <descriptor>, <url> <descriptor>`
    if (attribute.toLowerCase() === "srcset") {
      const srcSetParts = path.split(",").map((dirtyPart) => {
        const part = dirtyPart.trim();
        const [path, size] = part.split(" ");
        return `${new URL(path.trim(), baseUrl).toString()} ${size || ""}`;
      });
      return `${attribute}=${quote}${srcSetParts.join(", ")}${quote}`;
    }
    const absoluteURL = new URL(path, baseUrl).href;
    return `${attribute}=${quote}${absoluteURL}${quote}`;
  });
}
console.log(
  absolutify("<img src='./fooo.png'>", "https://example.com")
)