HTML-encoding lost when attribute read from input field

Question

I’m using JavaScript to pull a value out from a hidden field and display it in a textbox. The value in the hidden field is encoded.

For example,

Answer 1

Here's a non-jQuery version that is considerably faster than both the jQuery .html() version and the .replace() version. This preserves all whitespace, but like the jQuery version, doesn't handle quotes.

function htmlEncode( html ) {
    return document.createElement( 'a' ).appendChild( 
        document.createTextNode( html ) ).parentNode.innerHTML;
};

Speed: http://jsperf.com/htmlencoderegex/17

Demo:

Output:

Script:

function htmlEncode( html ) {
    return document.createElement( 'a' ).appendChild( 
        document.createTextNode( html ) ).parentNode.innerHTML;
};

function htmlDecode( html ) {
    var a = document.createElement( 'a' ); a.innerHTML = html;
    return a.textContent;
};

document.getElementById( 'text' ).value = htmlEncode( document.getElementById( 'hidden' ).value );

//sanity check
var html = '
   & hello
';
document.getElementById( 'same' ).textContent = 
      'html === htmlDecode( htmlEncode( html ) ): ' 
    + ( html === htmlDecode( htmlEncode( html ) ) );

HTML: