Question

I have a function in my nodejs application called get_source_at. It takes a uri as an argument and its purpose is to return the source code from that uri. My problem is that I don’t know how to make the function synchronously call request, rather than giving it that callback function. I want control flow to halt for the few seconds it takes to load the uri. How can I achieve this?

function get_source_at(uri){
    var source;
    request({ uri:uri}, function (error, response, body) {
        console.log(body);
    });
    return source;
}

Also, I’ve read about ‘events’ and how node is ‘evented’ and I should respect that in writing my code. I’m happy to do that, but I have to have a way to make sure I have the source code from a uri before continuing the control flow of my application – so if that’s not by making the function synchronous, how can it be done?

Answer 1

You should avoid synchronous requests. If you want something like synchronous control flow, you can use async.

async.waterfall([
    function(callback){
        data = get_source_at(uri);
        callback(null, data);
    },
    function(data,callback){
        process(data, callback);
    },
], function (err,result) {
    console.log(result)
});

The process is promised to be run after get_source_at returns.