NodeJS和MySQL的嵌套回调

Question

I have come to a time in my java-script adventure where I have needed to nest callbacks. I have the following code. I keep reading bout nested callbacks being hell... if someone could explain or help with the code. I am still very new to asynchronous programming. I am using nodejs , express 3.0 , jade , node-mysql

db_helper.getCategory(function (category) {
    db_helper.getCities(function (cities) {
             res.render('/search', category: category, cities: cities });

    });
});

i apologize for not really asking. Im wondering if this is ok to do this? Whats a better way to handle nested callbacks?

Answer 1

Take a look at the async npm module. It helps with organizing callbacks and avoiding the deep nesting you are referring to. Perhaps the waterfall would help.