mongodbs

This module allows your server to connect to multiple mongodb databases.
For every database instance connected it will create facilities to access data with basic CRUD operations (see Methods Facility section below).

Current features are:

• create connection(s) using a JSON configuration file
• create data CRUD methods using a JSON configuration file
• put database instance(s) into the express request

Database instance(s) will be optionally available in req.dbs[dbName]

Dependencies

• mongodb
• assert

Configure

Install module in your server

npm install --save mongodbs

Create a /path/to/conf.json configuration file like the following.

conf.json

[
  {
    "dbName": "myMongoDB",
    "dbHost": "localhost:27017/",
    "dbOptions": {
      poolSize: 10
    },
    "models": {
      "items": {
        "findOne": {
          "_id": "_id"
        },
        "find": {
          "name": "name",
          "category": "cat"
        },
        "updateOne": {
          "_id": "_id",
        },
        "update": {
          "name": "name"
        },
        "insert": {},
        "insertOne": {},
        "deleteOne": {
          "_id": "_id",
        },
        "delete": {
          "name": "name"
        }
      }
    }
  },
  ...
]

For a detailed explanation of conf params, please see the sections Configuration details and Methods Facility below.
Have a look at the json.sample files, you'll find examples of valid configurations

• mongo.json.sample
• mongo-replicaSet.json.sample
• mongo-shards.json.sample

Setup

Import in your server main file and initialize it

index.js

const express = require('express');
const mongo = require('mongodbs');
...

// you can set some options (see options.json.sample as reference)
const options = {
  ...
};
...

const app = express();
const mongodbs = await mongo(app, '/path/to/conf.json', options);
...


const port = 8080; // your port for this server
app.listen(port, () => console.log(`my awesome server is listening on port ${port}`));

or

const app = express();
mongo(app, '/path/to/conf.json', options)
.then(mongodbs => {  
  ...
  const port = 8080; // your port for this server
  app.listen(port, () => console.log(`my awesome server is listening on port ${port}`));
});

Use

If you set options, and set addDbsToReq to true (default) then in your routes you'll have

myRoute.js

app.get('/', (req, res, next) => {
  const db = req.dbs.myMongoDB;
  const coll = db.collection('myCollection');

  // here you can perform mongodb CRUD operations as usual
});

If you want you can also use the response outware by adding it as the latest middleware of a route, and adding a mongoResponse object to the res express object

myController.js

const myController = (req, res, next) => {
  // do stuffs
  res.mongoResponse = {
    statusCode: 200,
    data: { ... }
  };
  next();
};

myRoute.js

const out = require('mongodbs').response;

app.get('/', myController, out);

The out middleware will send the response back to the client.

Configuration details

Here is the list of valid configuration parameters:

• dbName (String) – the name of database you'll be connected to
• dbHost (String or Array) – the host(s) your mongo instance is running on
  Notes:
• a connection string must follow the rules of official mongodb (see mongodb - URI Connection Settings for details)
• if you set an array of hosts, the replicaSet param must be set as well
• replicaSet (String) – the replicaSet name for your mongo connection
• dbOptions (Object) – the options for your mongo connection (see mongodb - URI Connection Settings for details)
• models (Object) – the configuration for methods facility (see next section for details)

Methods Facility

The module takes your models settings from the conf.json file.
It examines the "models" entry for every database configuration and build access methods facility for you.

This is the reference of a "models" entry.

{
  "collection": {
    "method": {
      "name": "field"
    }
  }
}

where

• collection represents the collection in your DB you'll be querying with the created methods
  
• method is one of the CRUD operations
  Permitted values here are: delete, deleteOne, find, findOne, insert, insertOne, update and updateOne
  (Each one does what you expect it does)
• name is the value used for the method named
• field is the field name you would to query for in the collection

you'll find the generated methods like the following
dbs.databaseName.models.collection.methodName

Note that:

• a method not permitted will be ignored
• the method + name formula will be camel-cased (findOne + _id becomes findOneById)
• any value for the insert method will be ignored (current version)

Example

Given the conf.json above you'll have these methods:

• findOneById
• findByName
• findByCategory
• updateOneById
• updateByName
• insert
• insertOne
• deleteOneById
• deleteByName

Note that:

• insert and insertOne methods differs for args they expect to receive
  insert expect ad array of multiple object, insertOne a single object.

For example in your app you can use these facilities by doing this

const out = require('mongodbs').response;

const myController = (req, res, next) => {
  try {
    const items = await req.dbs.myMongoDB.models.items.findByName(req.params.name);
    res.mongoResponse = {
      statusCode: items.length ? 200 : 204,
      data: items
    };
    next();
  } catch(e) {
    res.status(500).send(e);
  }
};

app.get('/items/:name', myController, out);

Tests

By default the only enabled test is for the models methods facility.
You can edit the package.json file to enable the tests for replicaSet and shards. In this case be sure your mongo servers are configured and running accordingly with mongo-replicaSet.json.sample and mongo-shards.json.sample files.

Roadmap

• CRUD combined operations
• aggregations
• cursors facility

Changelog

v1.1.0

• Add support for replicaSet
• Add support for sharding
• Add support for mongo connect options

v1.0.0

• Created facility methods to perform basic CRUD operations over the database.
• Added the addDbsToReq option to optionally add the database instances into the express request.
• Added tests of the facility methods created by the module.
• connect and use methods are now deprecated.

v0.5.0

• Added the possibility to use mongodbs by passing your app express and a json configuration file. This behaviour is the same as what you would obtain by the calls to connect an use in sequence (v0.4).
• Added response outware.
• connect and use methods are not deprecated yet.