将第一个 img src 从解析的提要传递到另一个 elem 的 BG img 属性

Question

所以，本质上我正在使用jQuery解析一些RSS提要。我想获取最新解析的 IMAGE 并获取这个最新的（或第一个实例）img src并用它的内容填充我的第二个指定元素的 css background-image: 属性。因此，我从提要输出中img src的第一个实例也将用它的内容填充我的第二个元素的背景图像。我一直在使用以下逻辑。但是，我总是在控制台中得到background-image: 'undefined'。

由于某种原因，它不会从下面的第一行读取或捕获填充图像的第一个实例。

 var HeadImg = $('.featimg img').first().attr('src'); // not pulling
 $('.site-featured-content').css('background-image', 'url(' + HeadImg + ')');

下面是我的完整 JS 上下文。

我也尝试在 rss 提要 JS 之前和之后移动上述两行。

 jQuery(document).ready(function($){ 
  var url = window.location.href;
  if (url.indexOf('check') > -1) {  
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
  if (url.indexOf('movies') > -1) { 
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
  if (url.indexOf('host') > -1) { 
      $(".feed1").rss("http://www.dlisted.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://stupidcelebrities.net/feed/",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
if (url.indexOf('TheCollegeLife') > -1) { 
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
  if (url.indexOf('WingmanConnect') > -1) { 
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
  if (url.indexOf('Media2point0') > -1) { 
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
  }
  if (url.indexOf('Brokepoint') > -1) { 
      $(".feed1").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed2").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
      })
      $(".feed3").rss("http://www.thehollywoodgossip.com/rss.xml",
      {
        limit: 17,
        entryTemplate:'<h1 class="feedtitle"><a href="{url}">[{author}@{date}] {title}</a></h1><br/><div class="featimg">{teaserImage}</div><div class="feedtxt">{shortBodyPlain}</div>'
       })
    }
    var HeadImg = $('.featimg img').first().attr('src');
    $('.site-featured-content').css('background-image', 'url(' + HeadImg + ')');
})

---

Note:// 是的，<div class="featimg">{teaserImage}</div>呈现为<div class="featimg"><img class="class" src="/img.jpg"></div>

Answer 1

建议

：

function waitForCompleteRender()
{
    var HeadImg = $('.featimg img').first();
    if (HeadImg.length == 0) return setTimeout(waitForCompleteRender, 200);
    $('.site-featured-content').css('background-image', 'url(' + HeadImg.attr('src') + ')');
}
waitForCompleteRender();

编辑

请注意，这种方法对于生产用途来说是非常危险的（如果图像根本没有渲染）。您可能希望添加一个 if 语句，该语句将在 X 次后处理错误，但没有成功。