how to modify the document selection in javascript?

Question

I wanna modify the document selection (user currently selected by mouse or keyboard), how to do it in a cross browser way?

Answer 1

As an example, and the easiest one, let's say you want to move the user's selection to contain the contents of an element. The following will work in all major browsers:

function selectElementContents(el) {
    var body = document.body, range, sel;
    if (body.createTextRange) {
        range = body.createTextRange();
        range.moveToElementText(el);
        range.select();
    } else if (document.createRange && window.getSelection) {
        range = document.createRange();
        range.selectNodeContents(el);
        sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    }
}

selectElementContents( document.getElementById("someElement") );