使用内置 DOM 方法或 Prototype 从 HTML 字符串创建新的 DOM 元素

Question

I have an HTML string representing an element: '<li>text</li>' . I'd like to append it to an element in the DOM (a ul in my case). How can I do this with Prototype or with DOM methods?

(I know i could do this easily in jQuery, but unfortunately we're not using jQuery.)

Answer 1

Note: most current browsers support HTML <template> elements, which provide a more reliable way of turning creating elements from strings. See Mark Amery's answer below for details .

For older browsers, and node/jsdom : (which doesn't yet support <template> elements at the time of writing), use the following method. It's the same thing the libraries use to do to get DOM elements from an HTML string ( with some extra work for IE to work around bugs with its implementation of innerHTML ):

function createElementFromHTML(htmlString) {
  var div = document.createElement('div');
  div.innerHTML = htmlString.trim();

  // Change this to div.childNodes to support multiple top-level nodes
  return div.firstChild; 
}

Note that unlike HTML templates this won't work for some elements that cannot legally be children of a <div> , such as <td> s.

If you're already using a library, I would recommend you stick to the library-approved method of creating elements from HTML strings:

• Prototype has this feature built-into its update() method .
• jQuery has it implemented in its jQuery(html) and jQuery.parseHTML methods.

Answer 2

HTML 5 introduced the <template> element which can be used for this purpose (as now described in the WhatWG spec andMDN docs ).

A <template> element is used to declare fragments of HTML that can be utilized in scripts. The element is represented in the DOM as a HTMLTemplateElement which has a .content property of DocumentFragment type, to provide access to the template's contents. This means that you can convert an HTML string to DOM elements by setting the innerHTML of a <template> element, then reaching into the template 's .content property.

Examples:

/**
 * @param {String} HTML representing a single element
 * @return {Element}
 */
function htmlToElement(html) {
    var template = document.createElement('template');
    html = html.trim(); // Never return a text node of whitespace as the result
    template.innerHTML = html;
    return template.content.firstChild;
}

var td = htmlToElement('<td>foo</td>'),
    div = htmlToElement('<div><span>nested</span> <span>stuff</span></div>');

/**
 * @param {String} HTML representing any number of sibling elements
 * @return {NodeList} 
 */
function htmlToElements(html) {
    var template = document.createElement('template');
    template.innerHTML = html;
    return template.content.childNodes;
}

var rows = htmlToElements('<tr><td>foo</td></tr><tr><td>bar</td></tr>');

Note that similar approaches that use a different container element such as a div don't quite work. HTML has restrictions on what element types are allowed to exist inside which other element types; for instance, you can't put a td as a direct child of a div . This causes these elements to vanish if you try to set the innerHTML of a div to contain them. Since <template> s have no such restrictions on their content, this shortcoming doesn't apply when using a template.

However, template is not supported in some old browsers. As of April 2021, Can I use... estimates 96% of users globally are using a browser that supports template s . In particular, no version of Internet Explorer supports them; Microsoft did not implement template support until the release of Edge.

If you're lucky enough to be writing code that's only targeted at users on modern browsers, go ahead and use them right now. Otherwise, you may have to wait a while for users to catch up.

Answer 3

Use insertAdjacentHTML() . It works with all current browsers, even with IE11.

 var mylist = document.getElementById('mylist'); mylist.insertAdjacentHTML('beforeend', '<li>third</li>');

 <ul id="mylist"> <li>first</li> <li>second</li> </ul>

Answer 4

No need for any tweak, you got a native API:

const toNodes = html =>
    new DOMParser().parseFromString(html, 'text/html').body.childNodes[0]

Answer 5

Newer DOM implementations have range.createContextualFragment , which does what you want in a framework-independent way.

It's widely supported. To be sure though, check its compatibility down in the same MDN link, as it will be changing. As of May 2017 this is it:

Feature         Chrome   Edge   Firefox(Gecko)  Internet Explorer   Opera   Safari
Basic support   (Yes)    (Yes)  (Yes)           11                  15.0    9.1.2

Answer 6

For certain html fragments like <td>test</td> , div.innerHTML, DOMParser.parseFromString and range.createContextualFragment (without the right context) solutions mentioned in other answers here, won't create the <td> element.

jQuery.parseHTML() handles them properly (I extracted jQuery 2's parseHTML function into an independent function that can be used in non-jquery codebases).

If you are only supporting Edge 13+, it is simpler to just use the HTML5 template tag:

function parseHTML(html) {
    var t = document.createElement('template');
    t.innerHTML = html;
    return t.content;
}

var documentFragment = parseHTML('<td>Test</td>');

Answer 7

Heres a simple way to do it:

String.prototype.toDOM=function(){
  var d=document
     ,i
     ,a=d.createElement("div")
     ,b=d.createDocumentFragment();
  a.innerHTML=this;
  while(i=a.firstChild)b.appendChild(i);
  return b;
};

var foo="<img src='//placekitten.com/100/100'>foo<i>bar</i>".toDOM();
document.body.appendChild(foo);

Answer 8

You can create valid DOM nodes from a string using:

document.createRange().createContextualFragment()

The following example adds a button element in the page taking the markup from a string:

 let html = '<button type="button">Click Me!</button>'; let fragmentFromString = function (strHTML) { return document.createRange().createContextualFragment(strHTML); } let fragment = fragmentFromString(html); document.body.appendChild(fragment);

Answer 9

I am using this method (Works in IE9+), although it will not parse <td> or some other invalid direct childs of body:

function stringToEl(string) {
    var parser = new DOMParser(),
        content = 'text/html',
        DOM = parser.parseFromString(string, content);

    // return element
    return DOM.body.childNodes[0];
}

stringToEl('<li>text</li>'); //OUTPUT: <li>text</li>

Answer 10

With Prototype, you can also do:

HTML:

<ul id="mylist"></ul>

JS:

$('mylist').insert('<li>text</li>');

Answer 11

Why don't do with native js?

    var s="<span class='text-muted' style='font-size:.75em; position:absolute; bottom:3px; left:30px'>From <strong>Dan's Tools</strong></span>"
    var e=document.createElement('div')
    var r=document.createRange();
    r.selectNodeContents(e)
    var f=r.createContextualFragment(s);
    e.appendChild(f);
    e = e.firstElementChild;

Answer 12

To enhance furthermore the useful .toDOM() snippet that we can find in different places, we can now safely use backticks ( template literals ).

So we can have single and double quotes in the foo html declaration.

This behave like heredocs for those familiar with the term.

This can be enhanced furthermore with variables, to make complex templating:

Template literals are enclosed by the back-tick (`) (grave accent) character instead of double or single quotes. Template literals can contain placeholders. These are indicated by the dollar sign and curly braces (${expression}). The expressions in the placeholders and the text between them get passed to a function. The default function just concatenates the parts into a single string. If there is an expression preceding the template literal (tag here), this is called a "tagged template". In that case, the tag expression (usually a function) gets called with the processed template literal, which you can then manipulate before outputting. To escape a back-tick in a template literal, put a backslash \\ before the back-tick.

 String.prototype.toDOM=function(){ var d=document,i ,a=d.createElement("div") ,b=d.createDocumentFragment() a.innerHTML = this while(i=a.firstChild)b.appendChild(i) return b } // Using template literals var a = 10, b = 5 var foo=` <img onclick="alert('The future starts today!')" src='//placekitten.com/100/100'> foo${a + b} <i>bar</i> <hr>`.toDOM(); document.body.appendChild(foo);

 img {cursor: crosshair}

So, why not use directly .innerHTML += ? By doing so, the whole DOM is being recalculated by the browser, it's much slower.

https://caniuse.com/template-literals

Answer 13

Answer

• Create a Template
• Set the Template's innerHTML to your string .trim()
• Create an Array of Template's children
• Return children , child , or

 function toElement(s='',c,t=document.createElement('template'),l='length'){ t.innerHTML=s.trim();c=[...t.content.childNodes];return c[l]>1?c:c[0]||'';} console.log(toElement()); console.log(toElement('')); console.log(toElement(' ')); console.log(toElement('<td>With td</td>')); console.log(toElement('<tr><td>With t</td></tr>')); console.log(toElement('<tr><td>foo</td></tr><tr><td>bar</td></tr>')); console.log(toElement('<div><span>nested</span> <span>stuff</span></div>'));

Answer 14

I added a Document prototype that creates an element from string:

Document.prototype.createElementFromString = function (str) {
    const element = new DOMParser().parseFromString(str, 'text/html');
    const child = element.documentElement.querySelector('body').firstChild;
    return child;
};

Answer 15

HTML5 & ES6

<template>

Demo

 "use strict"; /** * * @author xgqfrms * @license MIT * @copyright xgqfrms * @description HTML5 Template * @augments * @example * */ /* <template> <h2>Flower</h2> <img src="https://www.w3schools.com/tags/img_white_flower.jpg"> </template> <template> <div class="myClass">I like: </div> </template> */ const showContent = () => { // let temp = document.getElementsByTagName("template")[0], let temp = document.querySelector(`[data-tempalte="tempalte-img"]`), clone = temp.content.cloneNode(true); document.body.appendChild(clone); }; const templateGenerator = (datas = [], debug = false) => { let result = ``; // let temp = document.getElementsByTagName("template")[1], let temp = document.querySelector(`[data-tempalte="tempalte-links"]`), item = temp.content.querySelector("div"); for (let i = 0; i < datas.length; i++) { let a = document.importNode(item, true); a.textContent += datas[i]; document.body.appendChild(a); } return result; }; const arr = ["Audi", "BMW", "Ford", "Honda", "Jaguar", "Nissan"]; if (document.createElement("template").content) { console.log("YES! The browser supports the template element"); templateGenerator(arr); setTimeout(() => { showContent(); }, 0); } else { console.error("No! The browser does not support the template element"); }

 @charset "UTf-8"; /* test.css */ :root { --cololr: #000; --default-cololr: #fff; --new-cololr: #0f0; } [data-class="links"] { color: white; background-color: DodgerBlue; padding: 20px; text-align: center; margin: 10px; }

 <!DOCTYPE html> <html lang="zh-Hans"> <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>Template Test</title> <!--[if lt IE 9]> <script src="https://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.js"></script> <![endif]--> </head> <body> <section> <h1>Template Test</h1> </section> <template data-tempalte="tempalte-img"> <h3>Flower Image</h3> <img src="https://www.w3schools.com/tags/img_white_flower.jpg"> </template> <template data-tempalte="tempalte-links"> <h3>links</h3> <div data-class="links">I like: </div> </template> <!-- js --> </body> </html>

Answer 16

Late but just as a note;

It's possible to add a trivial element to target element as a container and remove it after using.

// Tested on chrome 23.0, firefox 18.0, ie 7-8-9 and opera 12.11.

<div id="div"></div>

<script>
window.onload = function() {
    var foo, targetElement = document.getElementById('div')
    foo = document.createElement('foo')
    foo.innerHTML = '<a href="#" target="_self">Text of A 1.</a> '+
                    '<a href="#" onclick="return !!alert(this.innerHTML)">Text of <b>A 2</b>.</a> '+
                    '<hr size="1" />'
    // Append 'foo' element to target element
    targetElement.appendChild(foo)

    // Add event
    foo.firstChild.onclick = function() { return !!alert(this.target) }

    while (foo.firstChild) {
        // Also removes child nodes from 'foo'
        targetElement.insertBefore(foo.firstChild, foo)
    }
    // Remove 'foo' element from target element
    targetElement.removeChild(foo)
}
</script>

Answer 17

Fastest solution to render DOM from string:

let render = (relEl, tpl, parse = true) => {
  if (!relEl) return;
  const range = document.createRange();
  range.selectNode(relEl);
  const child = range.createContextualFragment(tpl);
  return parse ? relEl.appendChild(child) : {relEl, el};
};

And here u can check performance for DOM manipulation React vs native JS

Now u can simply use:

let element = render(document.body, `
<div style="font-size:120%;line-height:140%">
  <p class="bold">New DOM</p>
</div>
`);

And of course in near future u use references from memory cause var "element" is your new created DOM in your document.

And remember "innerHTML=" is very slow :/

Answer 18

Here's my code, and it works:

function parseTableHtml(s) { // s is string
    var div = document.createElement('table');
    div.innerHTML = s;

    var tr = div.getElementsByTagName('tr');
    // ...
}

Answer 19

For the heck of it I thought I'd share this over complicated but yet simple approach I came up with... Maybe someone will find something useful.

/*Creates a new element - By Jamin Szczesny*/
function _new(args){
    ele = document.createElement(args.node);
    delete args.node;
    for(x in args){ 
        if(typeof ele[x]==='string'){
            ele[x] = args[x];
        }else{
            ele.setAttribute(x, args[x]);
        }
    }
    return ele;
}

/*You would 'simply' use it like this*/

$('body')[0].appendChild(_new({
    node:'div',
    id:'my-div',
    style:'position:absolute; left:100px; top:100px;'+
          'width:100px; height:100px; border:2px solid red;'+
          'cursor:pointer; background-color:HoneyDew',
    innerHTML:'My newly created div element!',
    value:'for example only',
    onclick:"alert('yay')"
}));

Answer 20

I've linked from this article. ^{( Converting HTML string into DOM elements? )}

For me, I want to find a way to convert a string into an HTML element. If you also have this need, you can try the following

 const frag = document.createRange().createContextualFragment( `<a href="/link.js">js</a> <a>go</a> ` ) const aCollection = frag.querySelectorAll("a") for (let [key, a] of Object.entries(aCollection)) { console.log(a.getAttribute("href"), a.textContent) }

Answer 21

I have searched a lot for this myself and came across this solution which is neat.

const stringToHTML = (str) => {
    var parser = new DOMParser();
    var doc = parser.parseFromString(str, 'text/html');
    return doc.body;
};

String that I wanted to convert:

'<iframe src="https://player.vimeo.com/video/578680903?h=ea840f9223&amp;app_id=122963" width="640" height="360" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen title="Total Body Balance"></iframe>'

The result:

<body><iframe src="https://player.vimeo.com/video/578680903?h=ea840f9223&amp;app_id=122963" width="640" height="360" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" title="Total Body Balance"></iframe></body>

Answer 22

Example with latest JS:

<template id="woof-sd-feature-box">
<div class="woof-sd-feature-box" data-key="__KEY__" data-title="__TITLE__" data-data="__OPTIONS__">
    <h4>__TITLE__</h4>
    <div class="woof-sd-form-item-anchor">
        <img src="img/move.png" alt="">
    </div>
</div>

</template>

<script>
create(example_object) {
        let html = document.getElementById('woof-sd-feature-box').innerHTML;
        html = html.replaceAll('__KEY__', example_object.dataset.key);
        html = html.replaceAll('__TITLE__', example_object.dataset.title);
        html = html.replaceAll('__OPTIONS__', example_object.dataset.data);
        //convertion HTML to DOM element and prepending it into another element
        const dom = (new DOMParser()).parseFromString(html, "text/html");
        this.container.prepend(dom.querySelector('.woof-sd-feature-box'));
    }
</script>

Answer 23

Solution - works with all browsers since IE 4.0

var htmlString = `<body><header class="text-1">Hello World</header><div id="table"><!--TABLE HERE--></div></body>`;
var insertTableString = `<table class="table"><thead><tr><th>th cell</th></tr></thead><tbody><tr><td>td cell</td></tr></tbody></table>`;


var doc = document.implementation.createHTMLDocument();
    doc.open();
    doc.write(htmlString);
    doc.getElementById('table').insertAdjacentHTML('beforeend', tableString);
    doc.close();

console.log(doc);

Or you can use DOMParser

var doc = (new DOMParser).parseFromString(htmlString, "text/html");
    doc.getElementById('table').insertAdjacentHTML('beforeend', tableString);

console.log(doc);

Answer 24

function domify (str) {
  var el = document.createElement('div');
  el.innerHTML = str;

  var frag = document.createDocumentFragment();
  return frag.appendChild(el.removeChild(el.firstChild));
}

var str = "<div class='foo'>foo</div>";
domify(str);

Answer 25

You can use DOM parser:

const parser = new DOMParser();
const htmlString = "<strong>Beware of the leopard</strong>";
const doc3 = parser.parseFromString(htmlString, "text/html");

Reference

Answer 26

Visit https://www.codegrepper.com/code-examples/javascript/convert+a+string+to+html+element+in+js

const stringToHtml = function (str) {
    var parser = new DOMParser();
    var doc = parser.parseFromString(str, 'text/html');
    return doc.body;
}

Answer 27

You can use the following function to convert the text "HTML" to the element

 function htmlToElement(html) { var element = document.createElement('div'); element.innerHTML = html; return(element); } var html="<li>text and html</li>"; var e=htmlToElement(html);

Answer 28

Here is working code for me

I wanted to convert ' Text ' string to HTML element

var diva = UWA.createElement('div');
diva.innerHTML = '<a href="http://wwww.example.com">Text</a>';
var aelement = diva.firstChild;

Answer 29

var msg = "test" jQuery.parseHTML(msg)

Answer 30

var jtag = $j.li({ child:'text' }); // Represents: <li>text</li>
var htmlContent = $('mylist').html();
$('mylist').html(htmlContent + jtag.html());

Use jnerator

Answer 31

This will work too:

$('<li>').text('hello').appendTo('#mylist');

It feels more like a jquery way with the chained function calls.