使用 Javascript 以字符串形式获取 HTML 的 DocType
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Get DocType of an HTML as string with Javascript
提问by matte
I know that I can access to doctype object via document.doctypeor document.childNodes[0]but my problem is getting doctype as a string. I can do this in chrome and safari by calling document.doctypewhich returns <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">. However in Firefox, calling document.doctypereturns DocumentType object.
我知道我可以通过document.doctypeor访问 doctype 对象，document.childNodes[0]但我的问题是将 doctype 作为字符串获取。我可以在 chrome 和 safari 中通过调用document.doctypewhich 返回来做到这一点<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">。但是在 Firefox 中，调用document.doctype返回 DocumentType 对象。
Is there a way to get the the doctype string in all browsers as in chrome and safari?
有没有办法像在 chrome 和 safari 中一样在所有浏览器中获取 doctype 字符串？
Thanks!
谢谢！
回答by Rob W
In all compliant browsers (including Chrome/Safari), document.doctypealso returns a DocumentTypeobject. The following code can be used to generate a valid DOCTYPE string.
在所有兼容的浏览器（包括 Chrome/Safari）中，document.doctype也返回一个DocumentType对象。以下代码可用于生成有效的 DOCTYPE 字符串。
var node = document.doctype;
var html = "<!DOCTYPE "
+ node.name
+ (node.publicId ? ' PUBLIC "' + node.publicId + '"' : '')
+ (!node.publicId && node.systemId ? ' SYSTEM' : '')
+ (node.systemId ? ' "' + node.systemId + '"' : '')
+ '>';
This method returns the correct string for valid (HTML5) doctypes, eg:
此方法返回有效 (HTML5) doctypes的正确字符串，例如：
<!DOCTYPE html><!DOCTYPE html SYSTEM "about:legacy-compat"><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd">
<!DOCTYPE html><!DOCTYPE html SYSTEM "about:legacy-compat"><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd">
Explanation of the code:
代码说明：
node.name # Holds the name of the root element, eg: HTML / html
node.publicId # If this property is present, then it's a public document type.
#>Prefix PUBLIC
!node.publicId && node.systemId
# If there's no publicId, but a systemId, prefix SYSTEM
node.systemId # Append this if present
回答by Scott
You can also use this one liner to get the current doctype. This will work in any modern browser and IE 9 and higher.
您还可以使用这一行来获取当前的文档类型。这将适用于任何现代浏览器和 IE 9 及更高版本。
new XMLSerializer().serializeToString(document.doctype);
回答by codeassembly
function get_doctype()
{
var doctype =
'<!DOCTYPE ' +
document.doctype.name +
(document.doctype.publicId?' PUBLIC "' + document.doctype.publicId + '"':'') +
(document.doctype.systemId?' "' + document.doctype.systemId + '"':'') + '>';
return doctype;
}
回答by T1000
Is that what are you looking for ?
这就是你要找的吗？
alert(document.doctype.publicId);
回答by KooiInc
Concatenate DocumentType.name, .publicIdand .systemId. Something like:
连接DocumentType.name,.publicId和.systemId。就像是：
'<!DOCTYPE '+
DocumentType.name+' PUBLIC "'+ //maybe you should check for publicId first
DocumentType.publicId+'" "'+
DocumentType.systemId+'">'
