Validate a password field based on regular expression tests.

validate_password.js

/**
 * jQuery validatePassword plugin. Fire a callback function if the password passes the test or if it fails the tests.
 * @param expressions Object with a key => value pair of label => regex expression.
 * @param success_callback Function the callback to fire when the user passes all of the tests.
 * @param error_callback Function the callback to fire when the user fails any of the tests.
 * @return Object
 * 
 * Example: http://jsfiddle.net/WXqUZ/5/
 *     $('input[type=password]').validatePassword({
 *         'Uppercase': /([A-Z]+)/,
 *         'Lowercase': /([a-z]+)/,
 *         'Number': /([0-9]+)/
 *     }, function() {
 *         alert('All tests passed!');
 *     }, function() {
 *         console.log('Password is not strong enough.');
 *     });
 */
$.fn.validatePassword = function(expressions, success_callback, error_callback) {
    var self = $(this),
        object_size = Object.keys(expressions).length,
        li_width = ($('body').width() / object_size) - (2 * object_size),
        password_checks, expr, html, indicator;
    
    html = '<ul id="password-checks">';
    
    for(var i in expressions) {
        if(!expressions.hasOwnProperty(i)) {
            continue;
        }
        
        expr = expressions[i];
        html += '<li style="width: '+ li_width +'px">';
        html += '<span class="check-label">'+ i +'</span>';
        html += '<div id="indicator_'+ i +'" class="check-indicator"></div>';
        html += '</li>';
    }
    
    html += '</ul>';
    self.after(html);
    
    self.keyup(function() {
        for(var i in expressions) {
            expr = expressions[i];
            indicator = $('#indicator_'+ i);
            
            if(expr.test(self.val())) {
                indicator.addClass('ok');
            } else {
                indicator.removeClass('ok');
            }
        }
        
        if($('.ok').length == $('.check-indicator').length) {
            success_callback();
        } else {
            error_callback();
        }
    });
    
    return self;
};