javascript - Call to modules in specific order in node

Question

I've used the following code to call two modules, but the invoke action is called before the validate file (I saw in debug). What I should do to verify that validateFile is called before appHandler.invokeAction? Should I use a promise?

var validator = require('../uti/valid').validateFile();
var appHandler = require('../contr/Handler');
appHandler.invokeAction(req, res);

Update

this is the validate file code

var called = false;
var glob = require('glob'),
    fs = require('fs');
module.exports = {

    validateFile: function () {

        glob("myfolder/*.json", function (err, files) {
            var stack = [];
            files.forEach(function (file) {
                fs.readFile(file, 'utf8', function (err, data) { // Read each file
                    if (err) {
                        console.log("cannot read the file", err);
                    }
                    var obj = JSON.parse(data);
                    obj.action.forEach(function (crud) {
                        for (var k in crud) {
                            if (_inArray(crud[k].path, stack)) {

                                console.log("duplicate founded!" + crud[k].path);

                                break;
                            }
                            stack.push(crud[k].path);
                        }
                    })
                });
            });
        });
    }
};

Answer 1

Because glob and fs.readFile are async functions and appHandler.invokeAction is invoked during i/o from disk.

Promise is a good solution to solve this but an old school callback could do the job.

validator.validateFile().then(function() {
  appHandler.invokeAction(req, res);
});

and for validate

var Promise = require("bluebird"), // not required if you are using iojs or running node with `--harmony`
    glob = require('mz/glob'),
    fs = require('mz/fs');

module.exports = {
  validateFile: function () {
    return glob("myfolder/*.json").then(function(files) {
      return Promise.all(files.map(function(file) {
        // will return an array of promises, if any of them
        // is rejected, validateFile promise will be rejected
        return fs.readFile(file).then(function (content) {
          // throw new Error(''); if content is not valid
        });
      }));
    })
  }
};

If you want working with promise mz could help :)