Add spans to characters in a string (in an HTML element)

Question

I want to loop through the characters of a text in an element and add spans to the characters. This is pretty easy using jQuery.map():

$elem = $('h1');
var chars = jQuery.map($elem.text().split(''), function(c) {
  return '<span>' + c + '</span>';
});
$elem.html(chars.join('')); 

The above works great with a simple string, but now I want to change the function so that it also will handle more 'complex' contents like: <h1>T<em>e</em><b>st</b></h1>. Which should be translated to: <h1><span>T</span><em><span>e</span></em><b><span>s</span><span>t</span></b></h1>.

This means I cannot simply loop through all the characters in the element anymore. Is there something I can use to loop through the contents (characters) of an element as well as all children? Or is there another way of achieveing what I want?

Answer 1

Overall idea:

You can recursively iterate over the child nodes. If you encounter an element node, you iterate over its children etc. If you encounter a text node, you are replacing it with a series of span elements.

---

jQuery

function wrapCharacters(element) {
    $(element).contents().each(function() {
        if(this.nodeType === 1) {
            wrapCharacters(this);
        }
        else if(this.nodeType === 3) {
            $(this).replaceWith($.map(this.nodeValue.split(''), function(c) {
               return '<span>' + c + '</span>';
            }).join(''));
        }
    });
}    

wrapCharacters($('h1')[0]);

DEMO

---

JavaScript (without jQuery)

The idea stays the same, and even without jQuery, wrapping each character is not very difficult:

var d_ = document.createDocumentFragment();

for(var i = 0, len = this.nodeValue.length; i < len; i++) {
    var span = document.createElement('span');
    span.innerHTML = this.nodeValue.charAt(i);
    d_.appendChild(span);
}
// document fragments are awesome :)
this.parentNode.replaceChild(d_, this);

Only iterating over the child nodes has to be done carefully because text nodes are getting removed during iteration.

Plain JavaScript example