I'm creating a plugin and I need to know if the document is written in HTML5 or not.
I thought of using document.doctype , but I'm not sure what to compare it with since it compares with '<!DOCTYPE html>' false, because it's a node and not text.
How can I do this?
Have you ever tried to turn the object into a string?
var objSerializer = new XMLSerializer();
var doctypeName = objSerializer.serializeToString(document.doctype);
console.log(doctypeName);
Then you can do the comparison.
if(doctypeName == "<!DOCTYPE html>"){
console.log('É HTML 5');
}
Considering that HTML5 documents are declared in the block at the beginning with: <!DOCTYPE html> , in addition there are the old versions as shown in this address:
If the HTML5 document does not usually get versioned, it means that if you see a systemId or a publicId declared in your block and that is different from: SYSTEM "about:legacy-compat" . And that this document contains a type of doctype defined by <!DOCTYPE html> or <!doctype html> , we can do the following verification:
function checkHTML5() {
var isHtml5 = document.doctype.nodeName;
var systemId = document.doctype.systemId;
var publicId = document.publicId;
var xmlSerializer = new XMLSerializer();
var doctypeHTML = xmlSerializer.serializeToString(document.doctype);
var doctypeName = doctypeHTML.toLowerCase();
if (isHtml5 == "html" &&
(systemId == undefined ||
systemId.indexOf("about:legacy-compat")!==-1 ||
systemId == '') &&
publicId == undefined ||
publicId == '' &&
doctypeName.indexOf("!doctype") !== -1) {
return true;
}
console.log(publicId);
return false;
}
checkHTML5();