How can I make this call to request in nodejs synchronous?

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 can with deasync:

function get_source_at(uri){     var source;     request({ uri:uri}, function (error, response, body) {         source = body;         console.log(body);     });     while(source === undefined) {       require('deasync').runLoopOnce();     }     return source; } 

Answer 2

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.