I am trying to figure out whether I can build a web application completely on Ruby stack.
I am looking for following architecture:
Frontend <--- Websockets with Pub/Sub ---> Backend
On top of that, I really like Rails approach with "convention over configuration". As result, I am looking for some "opinionated" framework which will handle this scenario.
I know that it's easier to achieve with Javascript stack. As example using Sails.js.
However, it's experiment. So, I am not looking for the most efficient solution.
Has anybody build anything like that? What would be a reasonable set of libraries/frameworks to build something like it?
Since you said it's an experiment, I would recommend you to try out Volt. It uses Opal, which transcribes Ruby to JS and has reactive synchronization which Meteor.js is famous for. Also there are a lot of Railisms and you will find yourself in familiar waters very quickly.
Both technologies are not quite there yet, but there is a lot of hype around them and they will for sure play a big role in Ruby's near future.
As #ndn mentioned, Volt is interesting... But, it seems to me that the part I would adopt would be the Opal core for a front end.
Volt is too opinionated for me.
I would like to add my own pet project to the table, Plezi, which can be both an independent framework and can also run together within a Rails app by using the Iodine server.
I feel that Plezi has a much better balance between 'convention over configuration' and code-freedom. It manages the backend by automatically mapping websocket broadcasts/unicasts to their respective controller and method (broadcast :method, arg1, arg2...) and automatically maps Redis channels to controllers (or global multicasting) for easy scaling.
At the same time, Plezi does nothing for the front end and assume nothing regarding the front end. This is by design, both for better security (doesn't auto-trust incoming network data) and to allow for for the variety of possible clients such as native apps (iOS, android), browsers, scripts etc'... This would be where Opal can come in (or RubyMotion).
Related
Up to now I've always used PHP with or without a framework but a month ago I decided to start something new: Ruby and Rails, I found them quite easy and similar to PHP and some PHP frameworks in how they works but using a simpler syntax and many other advantages.
Some days ago I started reading about Node.js, Node.js vs Rails, "why node.js is better"...
I'm a bit confused but my objective is to learn something modern that will not become obsolete in a few months so:
What are the main differences between Rails/Ruby and Node.js and a framework based on it like Express.js (except that one is written in JS and the other in Ruby)?
What are the main advantages/disadvantages of using Node.js and framework based on it instead of a Ruby based solution like Rails?
Thanks!
There aren't enough differences between Node.js and Rails for it to practically matter.
A lot of what Node.js can do can be pulled off in Rails with things like EventMachine and Pusher. So unless you are really familiar with Rails' limitations, and know you'll be pushing the boundaries, you'd be hard pressed to make something a seasoned Rails developer couldn't do.
Having built apps in Node and Express I can say that they alone aren't enough to make a sexy application. They can seem just as old and stale if you don't have an outstanding frontend UI to facilitate the backend possibilities. Instead of comparing backend servers, I think the real future of doing amazing things is in front-end JavaScript frameworks like Backbone.js that use Express/Rails/Node.js on the backend.
I have chosen to go in the direction of Backbone.js with Rails as my backend API server. Because it's so easy to rapidly create a very nice RESTful backend server in Rails. Rails also makes working with CoffeeScript and precompiling/organizing Backbone code a breeze. There are already decent Backbone.js gems out there for Rails.
The Rails core is also able to acknowledge and embrace the fact that frontend JS MVCs are logically a good next step, and they have been working to strengthen the bond between the two. For those same reasons they have also worked to make Rails an even better API server so that it can work with frontend JS easier. Node.js and Express aren't putting as much effort to coordinate with frontend JavaScript MVCs as the Rails community is.
Being good with a JavaScript frontend MVC and Rails as a backend makes you also great for both worlds in terms of getting a job. You will easily be able to hop onto a Node.js project and add value to that team with your superior frontend experience, and you can also roll with the punches on a Ruby on Rails team and add value to them as well.
As official Node.js website explains it:
Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.
On the other hand Ruby on Rails official website says:
Ruby on Rails is an open-source web framework that's optimized for programmer happiness and sustainable productivity. It lets you write beautiful code by favoring convention over configuration.
Given this I guess that it is more appropriate to compare Ruby and Node.js, but even this is not quite right given that Ruby is programming language and Node.js is NOT. You could probably compare JavaScript with Ruby but I guess that is not what you meant to ask with this question :)
So, for me, key point in understanding what Node.js truly tries to accomplish is well described on Node.js about page. Key Node.js idea (for me) is described in this sentences:
Node is similar in design to and influenced by systems like Ruby's Event Machine or Python's Twisted. Node takes the event model a bit further—it presents the event loop as a language construct instead of as a library. In other systems there is always a blocking call to start the event-loop. Typically one defines behavior through callbacks at the beginning of a script and at the end starts a server through a blocking call like EventMachine::run(). In Node there is no such start-the-event-loop call. Node simply enters the event loop after executing the input script. Node exits the event loop when there are no more callbacks to perform. This behavior is like browser javascript—the event loop is hidden from the user.
What this should enable you, is that you should be able to easily write highly concurrent programs without even thinking about concurrency using JavaScript syntax and callback functions as basic concurrent runnable units.
Your fear that either Rails or Node.js will be gone in a week is unfounded. Rails has a large community and will be around for a very long time even though currently (early 2012) it's getting a bit of hate thrown its way. Node.js is just getting started and has so much attention I don't think it will have any problems getting to the Rails level some day.
That said I've been evaluating Node.js and Rails as options for a project and the reasons I choose Node.js over Rails are:
"The Rails Way" - In my (admittedly limited) experience with Rails it really seems like you either do it the Rails way or you are going to be in for a world of pain. A big part of the Rails way is to use the ActiveRecord model. The advantage of this is that there are a lot of gems that work with your code happily because they know you'll be using ActiveRecord. The disadvantage is you are mixing your data access & model. I am not a fan of this idea so the Rails way for me still seems a bit.. off.
JavaScript is a key part of client side web development and the idea of using it on the client and server is interesting. I'm not super strong at JavaScript and I can't imagine a better way to get better then to have to use it everywhere.
My project has real time communication needs which while I'm sure can be done in Rails there seems to be quite a bit of positive mention on Nodes ability to handle this with socket.io being the front runner option.
At the end of the day no matter which you choose you will have a great time & learn a ton of new stuff that will change how you write code. If you're not on a big time crunch I'd recommend building a small project management tool in both and see which you prefer.
Either way.. Good Luck!
2 things - performance & productivity.
Performance (more details here)
(source: jslang.info)
Productivity (how fast you can build that app)
Ruby on Rails is specialized and highly productive tool for creating so called Web 1.0 and Web 2.0 applications (99% of internet sites are such apps). In my subjective judgement and experience in this area Rails about 2-4 times more productive than node.js or express.js.
For Web 3.0 apps (realtime things, client-side MVC, etc.) this isn't true, RoR doesn't keep its advantage there.
So choice depends on use case and priorities.
I know a lot more about Node.js than I do about Ruby. That being said, Ruby is much more widely adopted. It is currently a very hot skill to have in the work place. Some may argue with me on this but I think that Node.js is still "under development" and will be for a little bit longer. It has a lot of promise but just hasn't been adopted by many companies and projects yet.
I am writing an application where the webapp will be rails and it will allow a user to input rules/ruby-logic and save them to the database. Later on, Java will come along and grab these rules (if/else/elseif) and will execute them via jruby engine. I am wondering of the negatives and possible side-effects of this? And having two languages here?
I want to do rails front-end because the available plugins, and speed of development of webapps. For example, groovy doesnt have as many plugins and i believe that it's much slower in development.
Am I missing anything, or possible logic that may be hurtful in the future if I choose this solution?
In addition I think since ruby is dynamic it will be easier for the user to input rules via a 'ruby' syntax instead of another third-party library like bean shell.
I feel like most complex applications end up needing several languages eventually, usually interfacing through the DB as you're planning. I'm not sure what constraint leads to you Java on backend rather than ruby (guessing legacy or performance), but if that's a requirement then your plan sounds reasonable.
As far as negatives/side-effects, Jruby seems to lag a bit behind the latest ruby, but that's not generally a big deal as long as you match versions for the UI & backend. I can't think of anything that would be harmful in this off the top of my head, but the devil is always in the details ;-)
I'm going to develop a collaborative site, and one of the features will be collaborative editing with realtime changes. i.e. when two or more users are editing the same doc, they can see each other changes as soon as they happen.
I have some experience with Ruby on Rails, so I was thinking about using EventMachine, but with all this hype around Node.js, I am know considering using it instead. So, what would be the main benefits of using Node.js instead of EventMachine?
tl;dr
What are the main differences between EventMachine and Node.js (besides the language)?
EventMachine has nothing to do with Rails apart from them both being written in the same language. You can get EventMachine as bare as Node.js; all you have to do is not add libraries to your project. In my experience the EventMachine libraries (like em-http) are much nicer than anything for Node. And you can use fibers instead of callbacks to avoid callback hell. Complete exception handling is pretty much impossible in Node because of all the callbacks. Plus Ruby is a nicer, more complete language than Javascript.
I tend towards the "use what you know" (even if it's a heavier architecture). Because of that, I don't see it being quite as simple as "EventMachine vs NodeJS." Mainly, the difference can be summarized as this:
NodeJS is a framework/language that was written to handle event based programming in JavaScript. That is its driving force. It's not an after thought, or a third party mechanism. It's baked right in to the language. You create callbacks/events because that's how the language is built. It's not a third party plug in, and doesn't alter your workflow.
EventMachine is a gem in Ruby that gives developers access to some of the goodness of the event based programming model. It's heavily used and well tested, but not baked directly in to the language. Both are locked to one CPU, but with event programming at Nodes core, it still has a leg up. Ruby wasn't written with concurrency in mind.
That said, technical problems can be overcome. The more important questions (from my view) that should guide your decision are these:
What will your production environment look like? Do you have complete control over the server? Can you host it however you want? Or will it be on a shared system to start with, and then you have to expand on that?
Do all the developers on your team have the ability to learn a new language very fast? How fast will they be able to understand an event-based language like JavaScript for the middle tier?
Do you need all of the architecture that Rails gives you (full Testing framework, scaffolding, models, controllers, etc)? Or is that overkill?
There are quite a few technical differences between the two. One is a language, one is a framework. Really, how heavy of a stack you want to run? How much learning will your developers have to do? Do you want a full stack the gives you a lot of niceties, that you may not use, or do you want a bare bones set up that runs extremely fast and concurrent, even though you may have to write extra boiler plate code and learn a new lanugage?
While Rails is not as heavy as some web application architectures, you're still going to need more processor power than you would to handle a similar amount of throughput in NodeJS. Assuming quality code for both systems. Bad code written on either stack is going to prevent the stack from shining. It really comes down to- Do you really want to learn a whole new way of doing things, or utilize your current understanding of Ruby to get things off the ground fast?
I know it's not really a definitive answer, but I hope this helps guide you to a decision!
One thing worth mentioning is the production story. EM, like most Rack stuff, has plenty of testing and monitoring tools available that are well tested, whereas Node.js falls well short in this respect.
At the time of writing, it seems almost impossible to get clear metrics from Node to answer questions like 'Do I need to scale'. There are options starting to form out there from the likes of Joyent, and always the roll-your-own argument, but nothing anywhere near tools such as NewRelic.
Node.js is very good from a performance / configurability point of view, but personally I wouldn't host it in production just yet.
Node.js
You get far better control low level control over what's going in. You can include general libraries to build on top of node.js to tweak your level of abstraction to your own liking. For example you can use connect or express depending on whether you want a view engine written for you.
You can use socket.io or now depending on how much you want your client-server connection abstracted. You can opt to include any of numerous MVC libraries or write your own.
Event-Machine
An asynchronous IO library just like node.js
It comes down to a Ruby vs JavaScript preference, how much flexibility you want with abstractions or lack of abstractions and whether you want to use node as your actual web server.
a detailed view at confusion has already been proposed... just a personal view
[] node.js will be better, if you are ready to learn and experiment more than you think because:
it's thread mechanism is awesome (inspired from that of 'erlang')
you can build a purpose specific server (easily) which will be real productive
Having a hard time getting any useful results from various searches on this concept -- probably because it's a. Wrong and/or b. obscure. Essentially, though, I'd like to write an application which works as either a normal web app or with a command-line interface. I've done this in the ancient past for sysadmin-y stuff using Perl, but that had none of the joy that using Ruby/Rails brings.
I am comfortable enough with Rails itself, and also use standalone Ruby for all manner of CLI stuff. What I'm looking for is best practices, if they exist, for extending a Rails application to have CLI functionality.
Perhaps the answer is as simple as using script/runner and doing my own "VC" while using my Rails models... This is what I was planning on doing, but I thought I'd step back and sanity-check that approach first. I'm having a hard time imagining how I'd utilize any of the Rails controller stuff, given that it's so tightly married to HTTP requests, but I'm often surprised by what clever(er) folks come up with.
Thanks for any useful responses.
I think it all depends on whether you want to reuse your controller logic. If you do then you can go down the route of writing a gem/Rake task/standalone Ruby script that makes HTTP requests to the application and receives the responses as JSON/XML/plain text or whatever. Something like HTTParty is ideal for this.
The second alternative is as you describe: drive your Rails models directly from your own script and present the results.
Another approach is that the web interface shells out to the CLI to do anything. Everything worth doing is in the CLI and the web just calls the CLI for all of its needs.
Shelling is a little bit expensive. If it turns out to hurt performance, use popen to load the CLI just once per web session. Then you can feed it commands (write to its stdin via the popen pipe) and get the results (read from its stdout via the popen pipe) without the CLI having to load for each command. If the CLI is of the "I take some arguments, do something, and exit" sort, then add a new mode to it "--stay-resident" or some-such, that switches it to the behavior that the web interface needs.
I am building a site that has a lot in common with a person-on-person chess site. I was thinking of using Rails for the front-end(User Registration, Navigation, etc) and something like Scala or Erlang for the engine(Game state and maybe AI). I was wondering -
Is this a good situation to use that type of design?
How exactly would be best to divide up the functionality between the components?
How would they best communicate with each other?
I'm open to any technologies or ideas.
If you're using Rails for the front-end, why not use Ruby?
If you like the idea of using Scala, why not use Lift for the front-end?
Chess is turn-based, and has a very simple board that can be handled with HTML and/or Javascript enhancements - so the basic model flows quite nicely with existing web frameworks.
With this in mind, Rails is a great choice for creating a web-based application. Rails is not just limited to crud applications, and in fact I think can write your entire app in Rails/Ruby - you don't really need to have an external engine.
Within the browser space, polling for turn updates can be done using XMLHttpRequest and a database can maintain the current game and turn state.
Looks like a simple Lift application to me. I'm not experienced with Lift, mind you, but it doesn't seem particularly more complex than the chat application that is so often demoed.
I would start by reading http://www.htdp.org/ How to Design Programs. The questions you have asked are very broad and difficult to answer without prefixing statements with "I believe that..."
I would code it in clojure (but that's just me).
I'm currently developing a suite of online games, using Scala. It's been absolutely fantastic - my game logic is much easier to get right with the static typing etc, and dealing with server/client protocol (a flash client, in this case) is made simpler via the use of Google Protocol Buffers.
If you're a huge fan of RoR, by all means use that. I think most statically typed languages are terrible to program websites in (Java, I'm looking at you here), but Scala gets rid of 90% of the pain, and gives even more safety.
Of course, it might not be your cup of tea. But I'd try just doing the entire thing in Scala, and adding another layer if that doesn't quite do it for you.
For question 1 Yes
And for 2 and 3 you need to give more information in order to get an answer that could help you.
Now I'm doing something like you but for the front end I'm going to use Grails. The reason are very simple: I like Grails, Scala and I want to mix them :)