How can I implement prepend and append with regular JavaScript? - javascript

How can I implement prepend and append with regular JavaScript without using jQuery?

Here's a snippet to get you going:
theParent = document.getElementById("theParent");
theKid = document.createElement("div");
theKid.innerHTML = 'Are we there yet?';
// append theKid to the end of theParent
theParent.appendChild(theKid);
// prepend theKid to the beginning of theParent
theParent.insertBefore(theKid, theParent.firstChild);
theParent.firstChild will give us a reference to the first element within theParent and put theKid before it.

Perhaps you're asking about the DOM methods appendChild and insertBefore.
parentNode.insertBefore(newChild, refChild)
Inserts the node newChild as a child of parentNode before the
existing child node refChild. (Returns newChild.)
If refChild is null, newChild is added at the end of the list of
children. Equivalently, and more readably, use
parentNode.appendChild(newChild).

You didn't give us much to go on here, but I think you're just asking how to add content to the beginning or end of an element?
If so here's how you can do it pretty easily:
//get the target div you want to append/prepend to
var someDiv = document.getElementById("targetDiv");
//append text
someDiv.innerHTML += "Add this text to the end";
//prepend text
someDiv.innerHTML = "Add this text to the beginning" + someDiv.innerHTML;
Pretty easy.

If you want to insert a raw HTML string no matter how complex, you can use:
insertAdjacentHTML, with appropriate first argument:
'beforebegin'
Before the element itself.
'afterbegin'
Just inside the element, before its first child.
'beforeend'
Just inside the element, after its last child.
'afterend'
After the element itself.
Hint: you can always call Element.outerHTML to get the HTML string representing the element to be inserted.
An example of usage:
document.getElementById("foo").insertAdjacentHTML("beforeBegin",
"<div><h1>I</h1><h2>was</h2><h3>inserted</h3></div>");
DEMO
Caution: insertAdjacentHTML does not preserve listeners that where attached with .addEventLisntener.

I added this on my project and it seems to work:
HTMLElement.prototype.prependHtml = function (element) {
const div = document.createElement('div');
div.innerHTML = element;
this.insertBefore(div, this.firstChild);
};
HTMLElement.prototype.appendHtml = function (element) {
const div = document.createElement('div');
div.innerHTML = element;
while (div.children.length > 0) {
this.appendChild(div.children[0]);
}
};
Example:
document.body.prependHtml(`Hello World`);
document.body.appendHtml(`Hello World`);

Here's an example of using prepend to add a paragraph to the document.
var element = document.createElement("p");
var text = document.createTextNode("Example text");
element.appendChild(text);
document.body.prepend(element);
result:
<p>Example text</p>

In order to simplify your life you can extend the HTMLElement object. It might not work for older browsers, but definitely makes your life easier:
HTMLElement = typeof(HTMLElement) != 'undefined' ? HTMLElement : Element;
HTMLElement.prototype.prepend = function(element) {
if (this.firstChild) {
return this.insertBefore(element, this.firstChild);
} else {
return this.appendChild(element);
}
};
So next time you can do this:
document.getElementById('container').prepend(document.getElementById('block'));
// or
var element = document.getElementById('anotherElement');
document.body.prepend(div);

In 2017 I know for Edge 15 and IE 12, the prepend method isn't included as a property for Div elements, but if anyone needs a quick reference to polyfill a function I made this:
HTMLDivElement.prototype.prepend = (node, ele)=>{
try { node.insertBefore(ele ,node.children[0]);}
catch (e){ throw new Error(e.toString()) } }
Simple arrow function that's compatible with most modern browsers.

var insertedElement = parentElement.insertBefore(newElement, referenceElement);
If referenceElement is null, or undefined, newElement is inserted at the end of the list of child nodes.
insertedElement The node being inserted, that is newElement
parentElement The parent of the newly inserted node.
newElement The node to insert.
referenceElement The node before which newElement is inserted.
Examples can be found here: Node.insertBefore

You can also use unshift() to prepend to a list

document.write() is not a good practice, some browsers like Chrome give you a warning if you use it, and it may be a bad solution if you are providing it to a customer, they don't want to use your code and see warnings in the debug console!
Also jQuery may also be a bad thing if you are giving your code to a customer who already uses jQuery for other functionality on their site, there will be a conflict if there is already a different version of jQuery running.
If you want to insert content into an iframe, and do that with pure JS, and with no JQuery, and without document.write(), I have a solution.
You can use the following steps
1.Select your iframe:
var iframe = document.getElementById("adblock_iframe");
2.Create an element that you want to insert into the frame, let's say an image:
var img = document.createElement('img');
img.src = "https://server-name.com/upload/adblock" + id + ".jpg";
img.style.paddingLeft = "450px";
//scale down the image is we have a high resolution screen on the client side
if (retina_test_media == true && high_res_test == true) {
img.style.width = "200px";
img.style.height = "50px";
} else {
img.style.width = "400px";
img.style.height = "100px";
}
img.id = "image";
3.Insert the image element into the iframe:
iframe.contentWindow.document.body.appendChild(img);

This is not best way to do it but if anyone wants to insert an element before everything, here is a way.
var newElement = document.createElement("div");
var element = document.getElementById("targetelement");
element.innerHTML = '<div style="display:none !important;"></div>' + element.innerHTML;
var referanceElement = element.children[0];
element.insertBefore(newElement,referanceElement);
element.removeChild(referanceElement);

Related

Replace an element with another element with pure JS [duplicate]

I am looking to replace an element in the DOM.
For example, there is an <a> element that I want to replace with a <span> instead.
How would I go and do that?
by using replaceChild():
<html>
<head>
</head>
<body>
<div>
<a id="myAnchor" href="http://www.stackoverflow.com">StackOverflow</a>
</div>
<script type="text/JavaScript">
var myAnchor = document.getElementById("myAnchor");
var mySpan = document.createElement("span");
mySpan.innerHTML = "replaced anchor!";
myAnchor.parentNode.replaceChild(mySpan, myAnchor);
</script>
</body>
</html>
A.replaceWith(span) - No parent needed
Generic form:
target.replaceWith(element)
Way better/cleaner than the previous method.
For your use case:
A.replaceWith(span)
Advanced usage
You can pass multiple values (or use spread operator ...).
Any string value will be added as a text element.
Examples:
// Initially [child1, target, child3]
target.replaceWith(span, "foo") // [child1, span, "foo", child3]
const list = ["bar", span]
target.replaceWith(...list, "fizz") // [child1, "bar", span, "fizz", child3]
Safely handling null target
If your target has a chance to be null, you can consider using the newish ?. optional chaining operator. Nothing will happen if target doesn't exist. Read more here.
target?.replaceWith?.(element)
Related DOM methods
Read More - child.before and child.after
Read More - parent.prepend and parent.append
Mozilla Docs
Supported Browsers - 97% Nov '22
var a = A.parentNode.replaceChild(document.createElement("span"), A);
a is the replaced A element.
This question is very old, but I found myself studying for a Microsoft Certification, and in the study book it was suggested to use:
oldElement.replaceNode(newElement)
I looked it up and it seems to only be supported in IE. Doh..
I thought I'd just add it here as a funny side note ;)
I had a similar issue and found this thread. Replace didn't work for me, and going by the parent was difficult for my situation. Inner Html replaced the children, which wasn't what I wanted either. Using outerHTML got the job done. Hope this helps someone else!
currEl = <div>hello</div>
newElem = <span>Goodbye</span>
currEl.outerHTML = newElem
# currEl = <span>Goodbye</span>
You can replace an HTML Element or Node using Node.replaceWith(newNode).
This example should keep all attributes and childs from origin node:
const links = document.querySelectorAll('a')
links.forEach(link => {
const replacement = document.createElement('span')
// copy attributes
for (let i = 0; i < link.attributes.length; i++) {
const attr = link.attributes[i]
replacement.setAttribute(attr.name, attr.value)
}
// copy content
replacement.innerHTML = link.innerHTML
// or you can use appendChild instead
// link.childNodes.forEach(node => replacement.appendChild(node))
link.replaceWith(replacement)
})
If you have these elements:
Link 1
Link 2
Link 3
Link 4
After running above codes, you will end up with these elements:
<span href="#link-1">Link 1</span>
<span href="#link-2">Link 2</span>
<span href="#link-3">Link 3</span>
<span href="#link-4">Link 4</span>
You can use replaceChild on the parent of the target element after creating your new element (createElement):
const newElement = document.createElement(/*...*/);
const target = document.getElementById("my-table");
target.parentNode.replaceChild(newElement, target);
If your starting point for the new element is HTML, you can use insertAdjacentHTML and then removeChild on the parent (or remove on the element itself, in modern environments):
const target = document.getElementById("my-table");
target.insertAdjacentHTML("afterend", theHTMLForTheNewElement);
target.parentNode.removeChild(target); // Or: `target.remove()`
Best way to do it. No parents need. Just use Element.outerHTML = template;
// Get the current element
var currentNode = document.querySelector('#greeting');
// Replace the element
currentNode.outerHTML =
'<div id="salutations">' +
'<h1>Hi, universe!</h1>' +
'<p>The sun is always shining!</p>' +
'</div>';
Example for replacing LI elements
function (element) {
let li = element.parentElement;
let ul = li.parentNode;
if (li.nextSibling.nodeName === 'LI') {
let li_replaced = ul.replaceChild(li, li.nextSibling);
ul.insertBefore(li_replaced, li);
}
}
Given the already proposed options the easiest solution without finding a parent:
var parent = document.createElement("div");
var child = parent.appendChild(document.createElement("a"));
var span = document.createElement("span");
// for IE
if("replaceNode" in child)
child.replaceNode(span);
// for other browsers
if("replaceWith" in child)
child.replaceWith(span);
console.log(parent.outerHTML);

How do we convert jQuery prepend() to VanillaJS [duplicate]

How can I implement prepend and append with regular JavaScript without using jQuery?
Here's a snippet to get you going:
theParent = document.getElementById("theParent");
theKid = document.createElement("div");
theKid.innerHTML = 'Are we there yet?';
// append theKid to the end of theParent
theParent.appendChild(theKid);
// prepend theKid to the beginning of theParent
theParent.insertBefore(theKid, theParent.firstChild);
theParent.firstChild will give us a reference to the first element within theParent and put theKid before it.
Perhaps you're asking about the DOM methods appendChild and insertBefore.
parentNode.insertBefore(newChild, refChild)
Inserts the node newChild as a child of parentNode before the
existing child node refChild. (Returns newChild.)
If refChild is null, newChild is added at the end of the list of
children. Equivalently, and more readably, use
parentNode.appendChild(newChild).
You didn't give us much to go on here, but I think you're just asking how to add content to the beginning or end of an element?
If so here's how you can do it pretty easily:
//get the target div you want to append/prepend to
var someDiv = document.getElementById("targetDiv");
//append text
someDiv.innerHTML += "Add this text to the end";
//prepend text
someDiv.innerHTML = "Add this text to the beginning" + someDiv.innerHTML;
Pretty easy.
If you want to insert a raw HTML string no matter how complex, you can use:
insertAdjacentHTML, with appropriate first argument:
'beforebegin'
Before the element itself.
'afterbegin'
Just inside the element, before its first child.
'beforeend'
Just inside the element, after its last child.
'afterend'
After the element itself.
Hint: you can always call Element.outerHTML to get the HTML string representing the element to be inserted.
An example of usage:
document.getElementById("foo").insertAdjacentHTML("beforeBegin",
"<div><h1>I</h1><h2>was</h2><h3>inserted</h3></div>");
DEMO
Caution: insertAdjacentHTML does not preserve listeners that where attached with .addEventLisntener.
I added this on my project and it seems to work:
HTMLElement.prototype.prependHtml = function (element) {
const div = document.createElement('div');
div.innerHTML = element;
this.insertBefore(div, this.firstChild);
};
HTMLElement.prototype.appendHtml = function (element) {
const div = document.createElement('div');
div.innerHTML = element;
while (div.children.length > 0) {
this.appendChild(div.children[0]);
}
};
Example:
document.body.prependHtml(`Hello World`);
document.body.appendHtml(`Hello World`);
Here's an example of using prepend to add a paragraph to the document.
var element = document.createElement("p");
var text = document.createTextNode("Example text");
element.appendChild(text);
document.body.prepend(element);
result:
<p>Example text</p>
In order to simplify your life you can extend the HTMLElement object. It might not work for older browsers, but definitely makes your life easier:
HTMLElement = typeof(HTMLElement) != 'undefined' ? HTMLElement : Element;
HTMLElement.prototype.prepend = function(element) {
if (this.firstChild) {
return this.insertBefore(element, this.firstChild);
} else {
return this.appendChild(element);
}
};
So next time you can do this:
document.getElementById('container').prepend(document.getElementById('block'));
// or
var element = document.getElementById('anotherElement');
document.body.prepend(div);
In 2017 I know for Edge 15 and IE 12, the prepend method isn't included as a property for Div elements, but if anyone needs a quick reference to polyfill a function I made this:
HTMLDivElement.prototype.prepend = (node, ele)=>{
try { node.insertBefore(ele ,node.children[0]);}
catch (e){ throw new Error(e.toString()) } }
Simple arrow function that's compatible with most modern browsers.
var insertedElement = parentElement.insertBefore(newElement, referenceElement);
If referenceElement is null, or undefined, newElement is inserted at the end of the list of child nodes.
insertedElement The node being inserted, that is newElement
parentElement The parent of the newly inserted node.
newElement The node to insert.
referenceElement The node before which newElement is inserted.
Examples can be found here: Node.insertBefore
You can also use unshift() to prepend to a list
document.write() is not a good practice, some browsers like Chrome give you a warning if you use it, and it may be a bad solution if you are providing it to a customer, they don't want to use your code and see warnings in the debug console!
Also jQuery may also be a bad thing if you are giving your code to a customer who already uses jQuery for other functionality on their site, there will be a conflict if there is already a different version of jQuery running.
If you want to insert content into an iframe, and do that with pure JS, and with no JQuery, and without document.write(), I have a solution.
You can use the following steps
1.Select your iframe:
var iframe = document.getElementById("adblock_iframe");
2.Create an element that you want to insert into the frame, let's say an image:
var img = document.createElement('img');
img.src = "https://server-name.com/upload/adblock" + id + ".jpg";
img.style.paddingLeft = "450px";
//scale down the image is we have a high resolution screen on the client side
if (retina_test_media == true && high_res_test == true) {
img.style.width = "200px";
img.style.height = "50px";
} else {
img.style.width = "400px";
img.style.height = "100px";
}
img.id = "image";
3.Insert the image element into the iframe:
iframe.contentWindow.document.body.appendChild(img);
This is not best way to do it but if anyone wants to insert an element before everything, here is a way.
var newElement = document.createElement("div");
var element = document.getElementById("targetelement");
element.innerHTML = '<div style="display:none !important;"></div>' + element.innerHTML;
var referanceElement = element.children[0];
element.insertBefore(newElement,referanceElement);
element.removeChild(referanceElement);

document.querySelector issues

In the following code, why is document.querySelector() returning null?
var element = document.createElement('div');
element.classList.add('abc');
var test = document.querySelector("." + element.className);
You need to add a .
var test = document.querySelector("."+element.className);
EDIT
You also need to add it to body
document.body.appendChild(element);
See http://codepen.io/jammer99/pen/dMmXYL
The div is not part of the DOM until you append it to a DOM element.
You need to add a dot in front to use the querySelector on a class string: document.querySelector("."+element.className)
The DOM element you append your div to has to exist before you can access it.
window.onload=function() { // body exists
var element = document.createElement('div');
element.classList.add('abc');
var test = document.querySelector("."+element.className);
console.log(test,element.className);
document.body.appendChild(element); // NOW the DIV exists in DOM
test = document.querySelector("."+element.className);
console.log(test);
}

How to surround element with div

How to surround element with div tag in dojo?
<button>Testing</button>
:
<div>
<button>Testing</button>
</div>
<div>Testing <span>something</span></div>
:
<div>
<div>Testing <span>something</span></div>
</div>
Finally I found answer
Surrounding
var node = domConstruct.create("div");
dojo.addClass(node,"container");
var refNode = dom.byId("refNode");
var tagName = refNode.tagName.toLowerCase();
node.innerHTML="<"+tagName+">"+refNode.innerHTML+"</"+tagName+">";
domConstruct.place(node, refNode,"before");
domConstruct.destroy(refNode);
Its pretty simple
require(["dojo/dom-construct"], function(domConstruct){
var n = domConstruct.create("div", { innerHTML: "Testing <span>something</span>" });
});
read all about it here
How about this :
var refNode = dom.byId("refNode");
// make the new div, with the correct class, directly after the node to be wrapped
var node = domConstruct.create("div", {"class":"container"}, refNode, "after");
// move the refNode inside our wrapping node
domContruct.place(refNode, node);
A quick and dirty approach looks like this:
element.outerHTML = '<div>' + element.outerHTML + '</div>';
No need for any libraries. Note, this will create a new object under the hood, so you have to retrieve element again to get the surrounding element, in case you need it afterwards.
Overall, it's handy, because you do not have to remove the old element and insert the new one.
I also came up with a similar approach to replace the tag name and preserve attributes, which might be interesting for one or another.
I don't know how it was in 2013, but these days, dojo's NodeList-manipulate functionality allows you to do it quite easily.
Given:
<b>one</b>
<b>two</b>
Use:
require(["dojo/query", "dojo/NodeList-manipulate"], function(query){
query("b").wrap("<div><span></span></div>");
});
Output:
<div><span><b>one</b></span></div>
<div><span><b>two</b></span></div>
This example is take from the documentation here.

How to replace DOM element in place using Javascript?

I am looking to replace an element in the DOM.
For example, there is an <a> element that I want to replace with a <span> instead.
How would I go and do that?
by using replaceChild():
<html>
<head>
</head>
<body>
<div>
<a id="myAnchor" href="http://www.stackoverflow.com">StackOverflow</a>
</div>
<script type="text/JavaScript">
var myAnchor = document.getElementById("myAnchor");
var mySpan = document.createElement("span");
mySpan.innerHTML = "replaced anchor!";
myAnchor.parentNode.replaceChild(mySpan, myAnchor);
</script>
</body>
</html>
A.replaceWith(span) - No parent needed
Generic form:
target.replaceWith(element)
Way better/cleaner than the previous method.
For your use case:
A.replaceWith(span)
Advanced usage
You can pass multiple values (or use spread operator ...).
Any string value will be added as a text element.
Examples:
// Initially [child1, target, child3]
target.replaceWith(span, "foo") // [child1, span, "foo", child3]
const list = ["bar", span]
target.replaceWith(...list, "fizz") // [child1, "bar", span, "fizz", child3]
Safely handling null target
If your target has a chance to be null, you can consider using the newish ?. optional chaining operator. Nothing will happen if target doesn't exist. Read more here.
target?.replaceWith?.(element)
Related DOM methods
Read More - child.before and child.after
Read More - parent.prepend and parent.append
Mozilla Docs
Supported Browsers - 97% Nov '22
var a = A.parentNode.replaceChild(document.createElement("span"), A);
a is the replaced A element.
This question is very old, but I found myself studying for a Microsoft Certification, and in the study book it was suggested to use:
oldElement.replaceNode(newElement)
I looked it up and it seems to only be supported in IE. Doh..
I thought I'd just add it here as a funny side note ;)
I had a similar issue and found this thread. Replace didn't work for me, and going by the parent was difficult for my situation. Inner Html replaced the children, which wasn't what I wanted either. Using outerHTML got the job done. Hope this helps someone else!
currEl = <div>hello</div>
newElem = <span>Goodbye</span>
currEl.outerHTML = newElem
# currEl = <span>Goodbye</span>
You can replace an HTML Element or Node using Node.replaceWith(newNode).
This example should keep all attributes and childs from origin node:
const links = document.querySelectorAll('a')
links.forEach(link => {
const replacement = document.createElement('span')
// copy attributes
for (let i = 0; i < link.attributes.length; i++) {
const attr = link.attributes[i]
replacement.setAttribute(attr.name, attr.value)
}
// copy content
replacement.innerHTML = link.innerHTML
// or you can use appendChild instead
// link.childNodes.forEach(node => replacement.appendChild(node))
link.replaceWith(replacement)
})
If you have these elements:
Link 1
Link 2
Link 3
Link 4
After running above codes, you will end up with these elements:
<span href="#link-1">Link 1</span>
<span href="#link-2">Link 2</span>
<span href="#link-3">Link 3</span>
<span href="#link-4">Link 4</span>
You can use replaceChild on the parent of the target element after creating your new element (createElement):
const newElement = document.createElement(/*...*/);
const target = document.getElementById("my-table");
target.parentNode.replaceChild(newElement, target);
If your starting point for the new element is HTML, you can use insertAdjacentHTML and then removeChild on the parent (or remove on the element itself, in modern environments):
const target = document.getElementById("my-table");
target.insertAdjacentHTML("afterend", theHTMLForTheNewElement);
target.parentNode.removeChild(target); // Or: `target.remove()`
Best way to do it. No parents need. Just use Element.outerHTML = template;
// Get the current element
var currentNode = document.querySelector('#greeting');
// Replace the element
currentNode.outerHTML =
'<div id="salutations">' +
'<h1>Hi, universe!</h1>' +
'<p>The sun is always shining!</p>' +
'</div>';
Example for replacing LI elements
function (element) {
let li = element.parentElement;
let ul = li.parentNode;
if (li.nextSibling.nodeName === 'LI') {
let li_replaced = ul.replaceChild(li, li.nextSibling);
ul.insertBefore(li_replaced, li);
}
}
Given the already proposed options the easiest solution without finding a parent:
var parent = document.createElement("div");
var child = parent.appendChild(document.createElement("a"));
var span = document.createElement("span");
// for IE
if("replaceNode" in child)
child.replaceNode(span);
// for other browsers
if("replaceWith" in child)
child.replaceWith(span);
console.log(parent.outerHTML);

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