Facebook刮板不加载动态元标记 [英] Facebook scraper doesn't load dynamic meta-tags
问题描述
/ **
*包含HTML属性：标题，描述和关键字标签）
* /
private void createHTMLheader（MyClass thing）{
String title = thing.getTitle（）;
String description = thing.getDescription（）;
Document.get（）。setTitle（title）;
MetaElement metaDesc = Document.get（）。createMetaElement（）;
metaDesc.setName（description）;
metaDesc.setContent（description）;
NodeList< Element> nodes = Document.get（）。getElementsByTagName（head）;
nodes.getItem（0）.appendChild（metaDesc）;
}
这是DOM上生成的HEAD。标题 aaaa 和元描述已被动态加载。 （谢谢CBroe的提示）。在视图源功能中，这些动态标签不会显示（仅适用于开发人员工具 - 查看dom）。
头>
< title> aaaa< / title>
< meta content =text / html; charset = utf-8http-equiv =content-type>
< meta name =descriptioncontent =我的描述>
< script language =javascripttype =text / javascriptsrc =dialective / dialective.nocache.js>< / script>< script defer =defer> ; dialective.onInjectionDone（ 'dialective'）< /脚本>
< / head>
原始HTML没有TITLE或META-DESCRIPTION标签。
Facebook刮板只能看到原始HTML响应中包含的< meta> 服务器。运行任何JavaScript代码，Flash插件，Java小程序或其他任何可能运行的完整浏览器的功能并不足够。
您需要使用服务器端框架在服务器上生成这些< meta> 标签。
此外，Facebook提供了一个方便测试工具，以确保您的网页公开适当的元标记。您可能还需要添加OpenGraph标签，例如 og：title 和 og：description 。
I am creating the HTML meta-tags dynamically using the function below (GWT). It takes 1 second to have this on the DOM. It is working fine except for Facebook. When I share a link from my web, the scraper gets the meta-tags that are in the HTML: none. How can I fix this?
/**
* Include the HTML attributes: title, description and keywords (meta tags)
*/
private void createHTMLheader(MyClass thing) {
String title=thing.getTitle();
String description=thing.getDescription();
Document.get().setTitle(title);
MetaElement metaDesc = Document.get().createMetaElement();
metaDesc.setName("description");
metaDesc.setContent(description);
NodeList<Element> nodes = Document.get().getElementsByTagName("head");
nodes.getItem(0).appendChild(metaDesc);
}
This is the resulting HEAD on the DOM. The title aaaa and meta-description has been loaded dynamically. (Thanks CBroe for the tip). In the "view source" functionality, these dynamic tags are not displayed (only on developer tools - view dom).
<head>
<title>aaaa</title>
<meta content="text/html; charset=utf-8" http-equiv="content-type">
<meta name="description" content="My description">
<script language="javascript" type="text/javascript" src="dialective/dialective.nocache.js"></script><script defer="defer">dialective.onInjectionDone('dialective')</script>
</head>
The original HTML doesn't have a TITLE or META-DESCRIPTION tags.
The Facebook scraper can only see <meta> tags included in the original HTML response from the server. It's not "smart enough" to run any JavaScript code, Flash plugins, Java applets, or anything else that a full-fledged browser might run.
You'll need to generate these <meta> tags on the server using a server side framework.
Also, Facebook provides a handy testing tool to make sure your page exposes the appropriate meta tags. You might need to add OpenGraph tags as well, such as og:title and og:description.
这篇关于Facebook刮板不加载动态元标记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！
