How to make mongoDB instance available all other modules in node.js

Question

How to make mongoDB instance available all other modules in node.js

In my application im using node.js with mongoDB.Below is my sample code.

var mongodb = require('mongodb');
var server = new mongodb.Server("localhost", 27017, {});

new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
    if (error) throw error;
    var collection = new mongodb.Collection(client, 'test_collection');
    collection.insert({hello: 'world'}, {safe:true},
    function(err, objects) {
        if(!err){
            console.log('Data inserted successfully.');
        }
        if (err && err.message.indexOf('E11000 ') !== -1) {
            // this _id was already inserted in the database
        }
    });
});

Now i need the mongoDB instance to other modules in my app.How can i do this.

node.js
mongodb

Answer 1

A simple way, if we assume the code you posted is in app.js you can rewrite line 2 to:

var server = exports.db = new mongodb.Server("localhost", 27017, {});

And in the modules that needs access to the instance simply write:

require('app').db

A more common way is probably to put shared stuff in a settings.js file or to have a dedicated database interface module.

Update

To get access to the opened client you'd in the same way expose the client:

new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
  exports.client = client;
  // ...
});