javascript - 如何从 response.body 获取 Node 中 '' 的绝对路径

Question

所以我想使用request-promise来拉取一个页面的body。获得页面后，我想收集所有标签并获取这些图像的 src 数组。假设页面上的 src 属性同时具有相对路径和绝对路径。我想要一个页面上 imgs 的绝对路径数组。我知道我可以使用一些字符串操作和 npm 路径来构建绝对路径，但我想找到一种更好的方法。

var rp = require('request-promise'),
    cheerio = require('cheerio');

var options = {
    uri: 'http://www.google.com',
    method: 'GET',
    resolveWithFullResponse: true
};

rp(options)
  .then (function (response) {
    $ = cheerio.load(response.body);
    var relativeLinks = $("img");
    relativeLinks.each( function() {
        var link = $(this).attr('src');
        console.log(link);
        if (link.startsWith('http')){
            console.log('abs');
        }
        else {
            console.log('rel');
        }
   });
});

结果

  /logos/doodles/2016/phoebe-snetsingers-85th-birthday-5179281716019200-hp.gif
  rel

Answer 1

将您的页面 URL 存储为变量，使用 url.resolve 将各个部分连接在一起。在 Node REPL 中，这适用于相对路径和绝对路径(因此称为“解析”):

$:~/Projects/test$ node
> var base = "https://www.google.com";
undefined
> var imageSrc = "/logos/doodles/2016/phoebe-snetsingers-85th-birthday-5179281716019200-hp.gif";
undefined
> var url = require('url');
undefined
> url.resolve(base, imageSrc);
'https://www.google.com/logos/doodles/2016/phoebe-snetsingers-85th-birthday-5179281716019200-hp.gif'
> imageSrc = base + imageSrc;
'https://www.google.com/logos/doodles/2016/phoebe-snetsingers-85th-birthday-5179281716019200-hp.gif'
> url.resolve(base, imageSrc);
'https://www.google.com/logos/doodles/2016/phoebe-snetsingers-85th-birthday-5179281716019200-hp.gif'

您的代码将更改为:

var rp = require('request-promise'),
    cheerio = require('cheerio'),
    url = require('url'),
    base = 'http://www.google.com';

var options = {
    uri: base,
    method: 'GET',
    resolveWithFullResponse: true
};

rp(options)
  .then (function (response) {
    $ = cheerio.load(response.body);
    var relativeLinks = $("img");
    relativeLinks.each( function() {
        var link = $(this).attr('src');
        var fullImagePath = url.resolve(base, link); // should be absolute 
        console.log(link);
        if (link.startsWith('http')){
            console.log('abs');
        }
        else {
            console.log('rel');
        }
   });
});