PageSpeed指责“渲染阻塞”脚本当使用外部图像时 [英] PageSpeed accuses script of "render-blocking" when using external image
问题描述
我在页面正文的结束标记之前放置了CDN中的脚本（位于< / body> 之上）。 Google的PageSpeed Insights表示：
消除以上折叠内容中的呈现屏蔽JavaScript和CSS
您的页面有1个阻止脚本资源。
在我的< / body> ; 不要延迟渲染？
经过一些试验和错误后，我发现这是由于我的页面使用外部图像。通过下面的例子，您可以使PageSpeed检测到渲染阻止脚本：
< body>
< img src =http://i.stack.imgur.com/oURrw.png/>
< script src =https://code.jquery.com/jquery-3.1.1.min.js>< / script>
< / body>
这是否真的会延迟渲染我的页面？
正确，他们没有。
例如，对于我来说，这个（带图片）会触发
https://code.jquery.com/jquery-3.1.1.min的呈现阻止警告。 js：
...
如果我删除
img，渲染阻塞JavaScript警告消失。
我会报告错误。我没有看到任何关于该脚本的渲染阻塞。我甚至尝试在固定大小的 overflow：none div 中包装 img code>，仍然有错误。看不到为什么该脚本会呈现阻塞状态;如果你将它报告为一个错误，结果是有原因的，那么这是一个好结果。但更可能是一个错误。
I have placed a script from a CDN just before the closing tag of my page's body (above </body>). Google's PageSpeed Insights says:
Eliminate render-blocking JavaScript and CSS in above-the-fold content
Your page has 1 blocking script resources. This causes a delay in rendering your page.
I thought scripts before the end of my </body> don't delay the rendering?
After some trial and error I found out that this is caused because my page uses an external image. With the example below you can cause PageSpeed to detect a "render-blocking" script:
<body>
<img src="http://i.stack.imgur.com/oURrw.png" />
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
</body>
Does this really cause a delay in rendering my page?
I thought scripts before the end of my
</body>don't delay the rendering?
Correct, they don't.
For instance, for me, this (with the image) triggers the render-blocking warning for
https://code.jquery.com/jquery-3.1.1.min.js:...
If I remove the
img, the render-blocking-JavaScript warning disappears.
I'd report that as a bug. I don't see anything render-blocking about that script. I even tried wrapping the img in a fixed-size, overflow: none div, and still got the error. Can't see why that script would be render-blocking; if you report it as a bug, and it turns out there's a reason, well, that's a good result. But more likely it's a bug.
这篇关于PageSpeed指责“渲染阻塞”脚本当使用外部图像时的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
