JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrap">
    <section>
        <h2>focus</h2>
        <input value="foo" class="old">

        <h2>mouseup</h2>
        <input value="bar" class="new">

    </section>
    
</div>

CSS

body { 
    color:#222; 
    background:#fafafa; 
}
h2 { 
    color:#999; 
    margin:25px 0 0 0; 
    font-size:1.6em; 
}


#wrap { 
    width:300px; 
    margin:1em auto; 
    padding:0 1.5em 1.5em 1.5em; 
    background:#fff;
    border:1px solid #eee;

}

JavaScript

$('.old').live('focus', function() {
    $(this).select();
});

$('.new').live('mouseup', function() {
    $(this).select();
});