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How to remove content within the &lt and &gt javascript

I have a content that contains a string of elements along with images. ex:
var str= <p><img src=\"v\">fwefwefw</img></p><p><br></p><p><br></p>
the text that is within the &lt and &gt is a dirty tag and I would like to remove it along with the content that is within it. the tag is generated dynamically and hence could be any tag i.e <div>, <a>, <h1> etc....
the expected output : <p></p><p><br></p><p><br></p>
however with this code, im only able to remove the tags and not the content inside it.
str.replaceAll(/<.*?>/g, "");
it renders like this which is not what im looking for:
<p>fwefwefw</p><p><br></p><p><br></p><p><br></p>
how can I possibly remove the & tags along with the content so that I get rid of dirty tags and text inside it?
fiddle: https://jsfiddle.net/3rozjn8m/
thanks

A safe way is to use a DOM parser, visiting each text node, where then each text can be cleaned separately. This way you are certain the DOM structure is not altered; only the texts:
let str= "<p><img src=\"v\">fwefwefw</img></p><p><br></p><p><br></p>";
let doc = new DOMParser().parseFromString(str, "text/html");
let walk = doc.createTreeWalker(doc.body, 4, null, false);
let node = walk.nextNode();
while (node) {
node.nodeValue = node.nodeValue.replace(/<.*>/gs, "");
node = walk.nextNode();
}
let clean = doc.body.innerHTML;
console.log(clean);
This will also work when you have more than one <p> element that has such content.

Remove the question mark.
var str= "<p><img src=\"v\">fwefwefw</img></p><p><br></p><p><br></p>";
console.log(str.replaceAll(/<.*>/g, ""));

How to use regex to replace text between tags

I'd like to replace some text in a string that represents a div tag that may or may not also include style and class attributes. For example,
var s = "<div style='xxx' class='xxx'>replaceThisText<div>
If it were just the tag, I believe I could just do this:
str = str.replace(/<div>[\s\S]*?<\/div>/, '<div>' + newText+ '<\/div>');
But how do I take the attributes into account?

Generate a temporary element with your string as HTML content then get the div within it to update content after updating the content get back the HTML of temporary element.
var s = "<div style='xxx' class='xxx'>replaceThisText<div>";
// create a temporary div element
var temp = document.createElement('div');
// set content as string
temp.innerHTML = s;
// get div within the temporary element
// and update the content within the div
temp.querySelector('div').innerHTML = 'newText';
// get back the current HTML content in the
// temporary div element
console.log(temp.innerHTML)
Why not regex?
RegEx match open tags except XHTML self-contained tags
Using regular expressions to parse HTML: why not?

Regex will never be a good decision to parse html content.
Consider the following short solution using DOMParser object(for browsers which support DOMParser implementation, see compatibility table):
var s = "<div style='xxx' class='xxx'>replaceThisText<div>",
tag = (new DOMParser()).parseFromString(s, 'text/html').querySelector('.xxx');
tag.textContent = 'newText'; // replacing with a new text
console.log(tag.outerHTML); // outputs the initial tag representation with replaced content
https://developer.mozilla.org/ru/docs/Web/API/DOMParser

Appending html as variable doesnt interpret tags

I have a variable which contains text and a tag. When appending variable to the element the tag isnt interpreted as a tag. Instead its interpreted as text.
Take this example:
var translationWrapper = $("<div class='list-label'></div>");
translationWrapper.html('<span> test </span>');
var translationContent = "";
translationContent += 'Testtext <em> test </em>';
translationWrapper.append(translationContent);
If I do this. The em tag isn't interpreted as a tag. Instead its interpreted as text. How can I let it interpret the tag ?

Before append you need to convert it to jQuery object
translationContent += 'Testtext <em> test </em>';
translationWrapper.append($(translationContent));

The comment from George Lee "solved" my issue. The problem is not in the provided code. It seems to be in my data.
using
jQuery(translationWrapper).append(translationContent);
works fine

How can I Strip all regular html tags except <a></a>, <img>(attributes inside) and <br> with javascript?

When a user create a message there is a multibox and this multibox is connected to a design panel which lets users change fonts, color, size etc.. When the message is submited the message will be displayed with html tags if the user have changed color, size etc on the font.
Note: I need the design panel, I know its possible to remove it but this is not the case :)
It's a Sharepoint standard, The only solution I have is to use javascript to strip these tags when it displayed. The user should only be able to insert links, images and add linebreaks.
Which means that all html tags should be stripped except <a></a>, <img> and <br> tags.
Its also important that the attributes inside the the <img> tag that wont be removed. It could be isplayed like this:
<img src="/image/Penguins.jpg" alt="Penguins.jpg" style="margin:5px;width:331px;">
How can I accomplish this with javascript?
I used to use this following codebehind C# code which worked perfectly but it would strip all html tags except <br> tag only.
public string Strip(string text)
{
return Regex.Replace(text, #"<(?!br[\x20/>])[^<>]+>", string.Empty);
}
Any kind of help is appreciated alot

Does this do what you want? http://jsfiddle.net/smerny/r7vhd/
$("body").find("*").not("a,img,br").each(function() {
$(this).replaceWith(this.innerHTML);
});
Basically select everything except a, img, br and replace them with their content.

Smerny's answer is working well except that the HTML structure is like:
var s = '<div><div>Link<span> Span</span><li></li></div></div>';
var $s = $(s);
$s.find("*").not("a,img,br").each(function() {
$(this).replaceWith(this.innerHTML);
});
console.log($s.html());
The live code is here: http://jsfiddle.net/btvuut55/1/
This happens when there are more than two wrapper outside (two divs in the example above).
Because jQuery reaches the most outside div first, and its innerHTML, which contains span has been retained.
This answer $('#container').find('*:not(br,a,img)').contents().unwrap() fails to deal with tags with empty content.
A working solution is simple: loop from the most inner element towards outside:
var $elements = $s.find("*").not("a,img,br");
for (var i = $elements.length - 1; i >= 0; i--) {
var e = $elements[i];
$(e).replaceWith(e.innerHTML);
}
The working copy is: http://jsfiddle.net/btvuut55/3/

with jQuery you can find all the elements you don't want - then use unwrap to strip the tags
$('#container').find('*:not(br,a,img)').contents().unwrap()
FIDDLE

I think it would be better to extract to good tags. It is easy to match a few tags than to remove the rest of the element and all html possibilities. Try something like this, I tested it and it works fine:
// the following regex matches the good tags with attrinutes an inner content
var ptt = new RegExp("<(?:img|a|br){1}.*/?>(?:(?:.|\n)*</(?:img|a|br){1}>)?", "g");
var input = "<this string would contain the html input to clean>";
var result = "";
var match = ptt.exec(input);
while (match) {
result += match;
match = ptt.exec(input);
}
// result will contain the clean HTML with only the good tags
console.log(result);

How to extract text directly under an HTML tag using Javascript

I need to extract the text that is directly under an HTML tag. For example, if my HTML looks like:
<span>This is Outside Text
<span>This is Inside Text</span>
</span>
then I need a way to extract ONLY "This is Outside Text" and NOT "This is Inside Text". I have tried "innerHTML", innerText", "textContent" and also tried to use RegEx (although I am not very good at it). But I am unable to find a solution. Any help would be much appreciated.
Please note that due to some technical constraints, I need to use "plain" Javascript ONLY and NOT jQuery (which I know is nothing but Javascript, but I am forbidden from using it for this solution)

With your HTML structure you can try this - DEMO
alert ( document.querySelector( "span" ).firstChild.nodeValue );

you can do it like this. it also works if you have more text after the second span.
<span id="span1">This is Outside Text
<span id="span2">This is Inside Text</span>
</span>
var element = document.getElementById("span1");
var element2 = document.getElementById("span2");
var text = element.textContent.replace(element2.textContent, "");
alert(text);
http://jsfiddle.net/btevfik/y58xJ/

You are looking for the text children (childNodes of type 3):
var children=document.getElementById("mySpan").childNodes,
count=children.length,
text="";
for (var i=0;i<count;i++) {
if (children[i].nodeType==3) {
text+=children[i].nodeValue;
}
}
Live demo: http://jsfiddle.net/aDgPj/