NodeJS Promise Example

nodejs_promise_example.js

var error = undefined;
var result = "wee!";

var chainableMethod = function () {
  return new Promise(function(resolve, reject) {
    if (error) {
      console.log('got error');
      return reject(error);
    }
    console.log('no error');
    return resolve(result);
  });
}

var call_chainable = function() {
  chainableMethod()
    .then(function(res){
      console.log(res);
    })
    .catch(function(err) {
      console.log(err);
    });
}

call_chainable();
error = "crap";
call_chainable();

// run: node app.js

// output:
// no error
// got error
// wee!
// crap