What's the common way to access a MongoDB with JavaScript? - javascript

Let's say I wrote a little HTML site, deployed on my nginx webserver. I created a database with MongoDB and stored several million entries in it. The MongoDB server is only listening on the local interface and accessible via localhost:27017.
Now I want to go to my webpage on my publicly accessible nginx webserver and access the entries in the database via JavaScript, by clicking a button "Show Users" or "Get latest entries" and so on. I need to perform only simple read-only-queries on the database like counting, searching, aggregating, and so on, so I don't need write access.
How do you generally implement this? Do I really need to set up PHP, Python, and Java to access the DB or is it somehow possible to solve this by only using HTTP/REST Interfaces? Can NodeJS help me to solve this? Do I have to remove nginx when using NodeJS?
Sorry, but I'm quite confused with all that JavaScript/ NodeJS/ mongoose/ MongoDB/ JSON stuff.

You can keep nginx as server for static content like your html files. To serve dynamic data, use node.js to create a rest interface. The rest interface will provide the data it fetches from your MongoDb.
Since you have millions of entries in your database and do not require complex functionality I would recommend the mongodb-native-driver as node.js module.
On the client, use ajax to perform api calls to your created rest interface.
Mongoose is built on top of the native driver to allow object modeling.

Related

Can I create web api using express.js and not have node.js installed?

I am currently in the process of creating a portfolio website for myself but due to hosting restrictions, I cannot make use of Node.js.
I know Angular can run on any web server, but is it possible to make use of Express.js to create web api's with relying on Node.js to run these web api's using Express.js?
If not, is there an alternative solution to create web api's that I can call using Angular and later for my mobile version of my website?
Please note that my shared hosting runs using cPanel.
As per definition Express.js, or simply Express, is a web application framework for Node.js so you can't do that. Alternatives would be to use a different backend language.
That also depends if your server supports them, for example, you can go with .NET CORE
You cannot use Express without NodeJS by definition so you have to deploy your backend somewhere else in you want to use it.
I suggest giving a look Firebase: you could write your backend using http cloud functions in express without paying anything until a reasonable amount of traffic (after that, is pretty cheap). You could also get rid of cPanel and deploy your frontend there via Firebase hosting.
Maybe you can try to build at first a web application with express. Of course you can create a web app without express if you need it. With express and Node.js I created a MySQL REST API. With HTML and Ajax you can fetch the Data from the API. So you can create two applications. One application where you need to run Node.js because it`s much easier to create a REST API with express. The second one is fully without Node.js.
Maybe there are better solutions, but inside each Web Application you can than but you can then access this API in any web application using jQuery. It doesn't matter if it is written with PHP, ASP.Net Core, Java EE / EE4J. You can also access this API in Ruby, Angular, React, Vue etc. using an AJAX request.
In some scenarios you can't start Node.js as a server because an application is already running on apache2 or nginx. There this would be a workaround to use something like this. For example, one could also integrate applications with HTML+JS in a CMS system that accesses other database tables and thus extend such a system without an iframe.
So can be helpful for few scenarios. Now just doesn't get around the actual goal of doing without Node.js completely or even express. But why are there REST APIs? So that you can query the data and incorporate it somewhere else. Otherwise you would have to build a REST API with another technology. Especially in the example of accessing MySQL with JavaScript, this would not be quickly feasible.
If you are looking for a similar solution to separate the web app and the REST API, but you don't need Node.js, then you should really build a REST API with .Net Core or with another technology, depending on what is possible and installed on your server. It could be Java or PHP behind it or Ruby.
The API that provides the REST access does not have to be written in JavaScript. You only need to be able to access it with JavaScript. So you can use many different approaches to access JSON data. I hope that in the short time with my bad English I have explained the basic idea, how to proceed stylistically and where advantages exist in REST interfaces.
With this, it should be self-explanatory that you don't have to use NodeJS and Express, but with JavaScript it's a pleasant solution. Only you have to ask yourself if a JavaScript application has to provide this interface at all or if in the end only a JavaScript application has to access this interface. Very big difference.
For backend rest api you can use golang with gorilla framework. Golang simple keyword and easy to learn.best important point is performance. If your server support golang you can use golang for backend..
ExpressJS is NodeJS framework so it's impossible to create an API without NodeJS.
Angular is front-end framework so you can host it on web hosting server.
If you need to create back-end APIs, you can use other clouding host servers that support NodeJS.
It's fairly simple to build this with just the net/http package. Set up a router that handles various commands and deal with the response accordingly.

Can database work be done with PHP instead of MongoDB in METEOR? [duplicate]

I've developed an application that I would like to use meteor.js for real time updates (I want to enhance but not change my program, for example when a user adds a comments make it update in real-time ) . Problem is meteor.js uses node.js (so javascript as server-side code). I use LAMP stack, Is it possible to get PHP to feed data into meteor.js from mysql.
Meteor is more than just an 'interactive webapplication'-builder or javascript framework. The idea is to have only one programming language (besides HTML/CSS for markup) to do all the work. Basically it creates a 'remote server' (in the clients browser) it can push data to and at the same time it publishes various API's to the users system. The data passed through these API's / connections has a specific structure which has to be adhered at all time.
Meteor is built around NodeJS, which makes it hard (if not impossible) to run it without this backend. Sure you can try to mimic the backend using PHP, but it would be a waste of time. Reading your question you'll be better of using a javascript framework like jQuery or Prototype. Unlike Meteor you will need to do the AJAX calls (POST & CallBack) yourself, but you can actually decide which backend you want to use yourself (including PHP / MySQL).
If you want to do this anyway you need to check the Meteor & NodeJS source code to see what the minimum requirements are to make Meteor run under PHP. The PHP stack has to interpret the commands Meteor sends and receivers, but this won't be an easy task.
You can use comet (or reverse ajax) for realtime updates.
Trying to marry node.js with PHP doesn't sound like a worthwhile path to go down. If someone insisted on using a system like Meteor.js, yet with a PHP back-end, it would make more sense to look at AngularJS which is mainly the client side.
Of course, that is different technology stack. If someone really insisted on the blending, one could consider using server side sockets to interact with PHP Web services; and/or use mongodb and/or mysql-node to interact with the same databases.
I released a meteorite package that interacts with a Wordpress site that has the Wordpress JSON API. A quick fix. For now.
Comes with a backend call that will return the raw data, or a publication that stores the posts using their id's instead of a randomly generated mongoid. And some basic templates to get you started including a Session variable that keeps track of the currently selected post.
I'm working on it a lot more and will eventually have a version that directly makes mysql calls from node so you won't need php or Wordpress; just the ability to access the mysql database (which can be remote, with the appropriate configuration, or on the same machine).

How to make CRUD operations on a remote Mongodb with Nodejs

I recently started to play around with NodeJS - all I know is that it's a server side technology. What I did and want to accomplish are as following:
I have a MongoDB running on a remote server. I am using nodejs mongodb driver, and by simply doing the following I can connect to the database and just lets say create a document:
// main.js
var MongoClient = require('mongodb').MongoClient;
MongoClient.connect('mongodb://remote_url:27017/mymongo', function(err, db) {
var document = {a:"1", b:"2"};
db.collection('collection').insert(document, function(err, records) {
if (err) throw err;
}
}
As you know, the code above requires a console call such: node main.js, however I have a HTML5 frontend with several text fields, and I want to pass the fields to my database with a simple button click event. My questions are:
Is it really stupid if I directly connect to remote mongodb as above? Can I call the script from my HTML page? If I can, then what are the drawbacks compared to redesigning it into a client-server structure?
Finally, I think the right practice to accomplish above is to create an http server with nodejs on the remote server which passes client's requests to the mongodb driver. Am I right?
You could try building a REST API to interact with the MongoDB server(s) using vanilla NodeJS or your choice of quite a few additional frameworks. You might try baucis*.
*Disclaimer: I am the main author of baucis
Is it really stupid if I directly connect to remote mongodb as above?
No, using the native MongoDB driver is pretty standard. However, instead of connecting and then immediately interacting with your database, I'd structure the application so that you connect and then wait for HTTP calls or some other function to interact with the database.
Can I call the script from my HTML page?
Absolutely. In your node.js application, I would build in a web server that listens for certain HTTP calls. In your HTML, provide links or forms to GET, POST, etc. the web server that your application is listening on.
For example, your front-end would look like maybe a <form action="/document/add" method="post">. Then, keep main.js as your back-end code running on node.js, but modify it to listen for a POST call to /document/add. When a call to that URL comes in, run the insert code with the POSTed form data.
You could also create an AJAX solution to listen for form submission and submit the POST in the background, wait for a response, and update the page accordingly.
What are the drawbacks compared to redesigning it into a client-server structure?
Advantages and drawbacks are going to be very specific to the type of application you want to create.
I think the right practice to accomplish above is to create an http server with nodejs on the remote server which passes client's requests to the mongodb driver. Am I right?
You are correct. That is pretty standard practice for using node.js and MongoDB. I'm going to recommend Express for creating your API to interface with the database. It provides features such as URL routing right out of the box. However, you can build your own platform, or use any other one that works for your application/environment.
You should use a REST interface for MongoDB. I like sleepy.mongoose a lot. It runs on python and can take a minute to set up, but is well worth the effort.
Here is a blog by the author which helped get me started.
Here is the Demo App deployed to Heroku,
http://nodejs-crud.herokuapp.com/ and the tutorial link is http://codeforbrowser.com/blog/crud-operations-in-node-js-and-mongodb/

JavaScript Application Storage Best Practices

This question is more of a theoretical one, than a programming one.
I am currently in the process of writing a single page javascript application with Knockout.js. I choose Knockout because I love the way it handles DOM updates, but it does require you to write your own REST backend for data storage and loading.
My application is an enterprise application, where the server and client will be installed on it's own server instance, and not shared with any other users. It does not require authentication, and only will only need to save and load JavaScript objects.
My original thought was to use a node.js backend with Mongo for storage, but this seems a little overkill for me. Would it be considered a bad practice to save the raw json as a flat file, and save/load it as needed? The only problem I see is if multiple users were using the application and try to save data at the same time. Is there an easy way to handle a merge of JSON data?
If there are concurrent access to your application that can modify this data I would definitely advise to keep it on the server side. It depends on your application, but merging the JSON will most likely become a nightmare. I believe it will be better to manage concurrent access from the backend. Mongo DB is a good option, but take a look at CouchDB (which provides REST interface) and Redis as well.
On the other hand, if concurrency was not an issue, you may want to check HTML5 local storage, which basically lets you store key/value pairs on the client side. It's a great alternative to cookies since it is not sent on each request and allows you to store more data in a cleaner way.

Connectin to MongoDB using Javascript

I am working on a little fun project(webcalender) and I want to use mongoDB. MongoDB is running and I figured out how to deal with it. I also got the connection to PHP.
I was wondering is there any chance to connect to the MongoDB using simple javascript?
I have searched a lot and I always passed by Node.js? Do I need Node.js to connect to mongoDB over Javascript?
Does anyone have a great link? Tutorial? or arguments why I should not do that?
Thanks for help
there are client side ways of doing this but its not safe at all.
there are a few reasons for the lack of security.
1. connection info is in the source for anyone to see.
2. if you use a service like mongoHQ where its a restful API to connect to Mongo your secret is exposed on the client side.
Both of these reasons scared me enough to not use a JS library that allowed me to connect to mongo on client side.
is your application being built in node? or PHP?
if PHP I know theres a PEAR library for MongoDB, then you can use javascript on the client side to interact with php to do what you need on the DB.
if the application is being built in node.js then sure why not? I've had success using Mongoose with express in node.
hope that helps.
Yes, you need Node.js to access MongoDB via JavaScript, because simple plain JavaScript runs on the user browser, not on the server, and Node.js is meant to run on the server.
Accessing a database directly from the browser would be a huge security issue, since JS files are always available to those viewing the page.

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