Javascript alternative to jquery html()

If node is a DOM node rather than an HTML string, you should use DOM methods instead on innerHTML:

while (document.body.firstChild) {
    document.body.removeChild(document.body.firstChild);
}
document.body.appendChild(node);

See MDC docs:

• firstChild
• removeChild
• appendChild

You are looking for the innerHTML property:

document.getElementById("test").innerHTML = "";

document.body.innerHTML = 'my html here';

And for the more general case than just setting the body....

// replace a single element by its ID
// i.e. $("#myDivId")
var myDiv = document.getElementById("myDivId");
myDiv.innerHtml = "foo";

// replace all elements of a given tag name
// i.e. $("span")
var allSpanTags = document.getElementsByTagName("span");
allSpanTags[0].innerHtml = "foo"; // or loop over the array or whatever.

// by class name
// i.e. $(".myClass")
var allMyClass = document.getElementsByClassName("myClass");

For reference, here's the way that jquery does it:

html: function( value ) {
    if ( value === undefined ) {
        return this[0] && this[0].nodeType === 1 ?
            this[0].innerHTML.replace(rinlinejQuery, "") :
            null;

    // See if we can take a shortcut and just use innerHTML
    } else if ( typeof value === "string" && !rnocache.test( value ) &&
        (jQuery.support.leadingWhitespace || !rleadingWhitespace.test( value )) &&
        !wrapMap[ (rtagName.exec( value ) || ["", ""])[1].toLowerCase() ] ) {

        value = value.replace(rxhtmlTag, "<$1></$2>");

        try {
            for ( var i = 0, l = this.length; i < l; i++ ) {
                // Remove element nodes and prevent memory leaks
                if ( this[i].nodeType === 1 ) {
                    jQuery.cleanData( this[i].getElementsByTagName("*") );
                    this[i].innerHTML = value;
                }
            }

        // If using innerHTML throws an exception, use the fallback method
        } catch(e) {
            this.empty().append( value );
        }

    } else if ( jQuery.isFunction( value ) ) {
        this.each(function(i){
            var self = jQuery( this );

            self.html( value.call(this, i, self.html()) );
        });

    } else {
        this.empty().append( value );
    }

    return this;
},

It uses innerHTML when it can, but it also has a fallback method.

If it's the body tag that you want HTML to be inserted into, try this:

document.body.innerHTML = node;

or

document.getElementsByTagName('body')[0].innerHTML = node;