Is it possible for a commonJS module to block until it exports?

Question

Is it possible for a commonJS module to block until it exports?

I understand CommonJS modules actually block as they load.

In some cases I wish to do particular work - loading and parsing config files for my app server - in a blocking way, i.e, since the app isn't usable until those files have loaded, only export once those async operations are complete.

Can I delay exporting until after an async operation in CommonJS? Or should I just use sync file reading / parsing methods instead?

node.js
asynchronous
commonjs

Answer 1

You can export a function with a callback as parameter:

var fs = require('fs');

function parseContent(content) {
    // do the content parsing
}

exports.getFileData = function (callback) {
    fs.readFile('path/to/file', function (error, content) {
        var data;

        if (error) {
            throw error;
        } else {
            data = parseContent(content);
            callback(data);
        }
    });
};

usage:

moduleName.getFileData(function (data) {
    // process data
});