问题
We're looking for ways to create a DOM document in javascript from a string, but without using Jquery. Is there a way to do so? [I would assume so, since Jquery can do it!]
For those curious, we can't use Jquery, becase we're doing this in the context of a Chrome application's content script, and using Jquery would just make our content script too heavy.
回答1:
In case you're still looking for an anwer, and for anyone else coming accross it, I just have been trying to do the same thing myself. It seems you want to be looking at javascript's DOMImplementation:
http://reference.sitepoint.com/javascript/DOMImplementation
There are few references to compatibility as well here, but it's fairly well supported.
In essence, to create a new document to manipulate, you want to create a new Doctype object (if you're going to output some standards based stuff) and then create the new Document using the newly created Doctype variable.
There are multiple options to be put into both the doctype and the document, but if you're creating an HTML5 document, it seems you want to leave most of them as blank strings.
Example (New HTML5 DOM Document):
var doctype = document.implementation.createDocumentType( 'html', '', '');
var dom = document.implementation.createDocument('', 'html', doctype);
The new Document now looks like this:
<!DOCTYPE html>
<html>
</html>
Example (New XHTML DOM Document):
var doctype = document.implementation.createDocumentType(
'html',
'-//W3C//DTD XHTML 1.0 Strict//EN',
'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd'
);
var dom = document.implementation.createDocument(
'http://www.w3.org/1999/xhtml',
'html',
doctype
);
So it's up to you to populate the rest of it. You could do this as simply as changing
dom.documentElement.innerHTML = '<head></head><body></body>';
Or go with the more rigorous:
var head = dom.createElement( 'head' );
var body = dom.createElement( 'body' );
dom.documentElement.appendChild(head);
dom.documentElement.appendChild(body);
All yours.
回答2:
https://developer.mozilla.org/en-US/docs/Web/API/DOMParser
var parser = new DOMParser();
var doc = parser.parseFromString("<html_string>", "text/html");
(the resulting doc variable is a documentFragment Object).
回答3:
createDocumentFragment may help you.
https://developer.mozilla.org/En/DOM/DocumentFragment
Browsers always create document by themselves with empty page (about:blank). Maybe, in Chrome application there're some functions available (like XUL in FF), but there's no such function in ordinary javascript.
回答4:
var dom = '<html><head>....</head><body>...</body></html>';
document.write(dom);
document.close();
回答5:
HTML would like this:
<html>
<head></head>
<body>
<div id="toolbar_wrapper"></div>
</body>
</html>
JS would look like this:
var data = '<div class="toolbar">'+
'<button type="button" class="new">New</button>'+
'<button type="button" class="upload">Upload</button>'+
'<button type="button" class="undo disabled">Undo</button>'+
'<button type="button" class="redo disabled">Redo</button>'+
'<button type="button" class="save disabled">Save</button>'+
'</div>';
document.getElementById("toolbar_wrapper").innerHTML = data;
回答6:
I tried some of the other ways here but there where issues when creating script elements such as Chrome refusing to load the actual .js file pointed to by the src attribute. Below is what works best for me.
It's up to 3x faster than jQuery and 3.5x faster than using DOMParser, but 2x slower than programmatically creating the element.
https://www.measurethat.net/Benchmarks/Show/2149/0
Object.defineProperty(HTMLElement, 'From', {
enumerable: false,
value: (function (document) {
//https://www.measurethat.net/Benchmarks/Show/2149/0/element-creation-speed
var rgx = /(\S+)=(["'])(.*?)(?:\2)|(\w+)/g;
return function CreateElementFromHTML(html) {
html = html.trim();
var bodystart = html.indexOf('>') + 1, bodyend = html.lastIndexOf('<');
var elemStart = html.substr(0, bodystart);
var innerHTML = html.substr(bodystart, bodyend - bodystart);
rgx.lastIndex = 0;
var elem = document.createElement(rgx.exec(elemStart)[4]);
var match; while ((match = rgx.exec(elemStart))) {
if (match[1] === undefined) {
elem.setAttribute(match[4], "");
} else {
elem.setAttribute(match[1], match[3]);
}
}
elem.innerHTML = innerHTML;
return elem;
};
}(window.document))
});
Usage Examples:
HTMLElement.From(`<div id='elem with quotes' title='Here is "double quotes" in single quotes' data-alt="Here is 'single quotes' in double quotes"><span /></div>`);
HTMLElement.From(`<link id="reddit_css" type="text/css" rel="stylesheet" async href="https://localhost/.js/sites/reddit/zinject.reddit.css">`);
HTMLElement.From(`<script id="reddit_js" type="text/javascript" async defer src="https://localhost/.js/sites/reddit/zinject.reddit.js"></script>`);
HTMLElement.From(`<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">`);
HTMLElement.From(`<div id='Sidebar' class='sidebar' display=""><div class='sb-handle'></div><div class='sb-track'></div></div>`);
回答7:
I was able to do this by writing the html string on an iframe
const html = `<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
</body>
</html>`
const iframe = document.createElement('iframe')
iframe.contentDocument.open()
iframe.contentDocument.write(html)
iframe.contentDocument.close()
iframe.addEventListener('load', () => {
myDocumentObject = iframe.contentDocument
})
回答8:
fetch("index.html", { // or any valid URL
method: "get"
}).then(function(e) {
return e.text().then(e => {
var t = document.implementation.createHTMLDocument("");
t.open();
t.write(e);
t.close();
return t;
});
}).then(e => {
// e will contain the document fetched and parsed.
console.log(e);
});
回答9:
The DOM element has the property innerHTML that allows to change completely its contents. So you can create a container and fill it with a new HTML content.
function createElementFromStr(htmlContent) {
var wrapperElm = document.createElement("div");
wrapperElm.innerHTML = htmlContent; // Ex: "<p id='example'>HTML string</p>"
console.assert(wrapperElm.children.length == 1); //Only one child at first level.
return wrapperElm.children[0];
}
* I know it is an old question, but i hope to help someone else.
来源：https://stackoverflow.com/questions/9598791/create-a-dom-document-from-string-without-jquery