How to get css islolation random string-CodePudding

I use CSS isolation.
This is the output html code:

<div b-1yc1hoca3 >Text</div>

.test {
    border: 1px solid red;
}

Random string that CSS isolation generates is: b-1yc1hoca3
I add some html code after page loaded.

$('#main').append(`<div >Text</div>`);

When above codes will be add, above codes doesn't have CSS isolation random string (b-1yc1hoca3) and CSS codes doesn't apply to the element.
How can I get CSS isolation random string with JQuery to added to below codes:

$('#main').append(`<div >Text</div>`);

Just only thing I need is b-1yc1hoca3.
For example

var cssIsolationRandomString = $('.test').attr('cssIsloationRandomString');
$('#main').append(`<div ${cssIsolationRandomString} >Text</div>`);

As far as I know, all CSS isolation random string starts with b-.

The problem is CSS isolation random strings are random strings and I don't know how to get a random attribute that start with b-

CodePudding user response：

First of all, I found a

<div id="dynamicContent">
    <p id="targetItem">hello this is content in red</p>
</div>
<button id="add">add section</button>

@section Scripts{
     <script>
        $("#add").click(function(){
            var attrs = document.getElementById("targetItem").attributes;
            console.info(attrs);
            var isolation = "";
            $.each(attrs,function(i,elem){
                if (elem.name.startsWith("b-")){
                    isolation = elem.name;
                }
            });
            $('#dynamicContent').append("<p " isolation " >added content</p>");
        })
    </script>
}