Building a mutliplayer game site - ruby-on-rails

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 :)

Related

What's the best way to do classical forms over data using Node.js?

I am in the need of creating a classical forms-over-data application using Node.js, including server-side rendering. I know that this is definitely not a good use case for Node.js for various reasons, nevertheless, I have to do it.
So let's please avoid discussion whether this is meaningful, or similar things - just take it as given.
Now I wonder what's the best way to fulfill this task. Of course, I could create such an app completely manually, using Express and MongoDB, and hand-writing routes and controllers, and stuff like this. It's basically not a big deal, but this compares quite bad to solutions such as ASP.NET MVC (which I'd prefer for this kind of task, to be true).
Now I found out about Sails.js, which is a heavily Rails-inspired MVC framework for Node.js, and which looks quite good. But before I now start experimenting in more depth with Sails.js, I wanted to ask what other options might be viable?
Any suggestions?
If you have ruby on rails 2.x background then check this out http://compoundjs.com/
rails 3.x check this http://tower.github.io/ or sails.js or geddyjs

Is Rails much better for interactive website compare to Django?

Just got a new website project for my company internal use. The whole website isn't that complicating but requires quite a lot of real time interaction. Basically, it's an interactive time line table where we can freely drag and drop each elements to move and resize them.
At first I wanted to use this opportunity to learn Python+Django (I'm given a huge amount of time) but then I read around and a lot of people mentioned Rails is better for creating rich interactive website.
So, for a website with a lot of drag & drop interaction like this, is Rails really the better choice? Is Rails built-in ajax that much easier to work with compare to Django+jQuery? How flexible and customizable is Rails' built-in ajax? I want to learn RoR just as much as Python by thee way.
I don't think AJAX functionality will define which framework you find yourself preferring.
I can't answer most of your question relating to ajax, but still think this post could be useful for you: it's highlighting a huge difference between ROR and django -- mainly RoR uses magic, django doesn't.
I prefer django for exactly that. Others may prefer RoR for the same reason I don't.
What's wrong with "magic"?
Rails' developers are of the opinion
that this sort of "magic" is a good
thing because it makes it easier to
quickly get something working, and
doesn't bore you with lots of details
unless you want to reach in and start
overriding things.
Django's developers are of the opinion
that this sort of "magic" is a bad
thing because doesn't really save all
that much time (a few import
statements isn't a big deal in the
grand scheme of things), and has the
effect of hiding what's really going
on, making it harder to work out how
to override stuff, or harder to debug
if something goes wrong.
Both of these are, of course, valid
stances to take, and generally it
seems that people just naturally
gravitate to one or the other; those
who like the "magic" congregate around
Rails or frameworks which try to
emulate it, those who don't congregate
around Django or frameworks which try
to emulate it (and, in a broader
sense, these stances are somewhat
stereotypical of Ruby and Python
developers; Ruby developers tend to
like doing things one way, Python
developers tend to like doing things
another way).
So I think one will click for you regardless of out of the box ajax support.
Speaking as someone who mostly works on Rails, I would say take a day with each framework, follow a "getting started" screencast or tutorial, or pick up a book. ( For rails, I recommend Beginning Rails 3 ). Then, keep going with whichever one you feel more comfortable with.
One amazing resource rails has is Railscasts. Railscasts almost single-handedly converted me from PHP to ROR. I don't know if Django has a similar volume of quality screencasts available or not.
All frameworks are pretty heavily focused on the server-side of the equation. Now, Rails has a lot of things that help make writing views (your drag and drop stuff) nice, such as HAML (a fantastic template language)... and while I don't know enough to post links I'm sure Django has similar helpers. It's worth noting that both Django and Rails can use jQuery or any other javascript framework.
But, in the end, just by the nature of the web as stateless, there's going to be a degree of independence between your client-side templates and javascript, and what's serving that from the server side.
The real question you should probably be focused on is: Do you want to become a jQuery ninja, or do you want to scale up a notch and focus on Javascript itself, perhaps using tool suites like MooTools or Prototype. Your drag and drop stuff is client-side, so that's where your toughest decisions will have to be made.
Good luck!
I used to worry about things like this and would try new frameworks all the time because people would say it was a big improvement over the last one I was using until I realised I wasn't doing anything. Now I just pick one and stick with it. The fact that I know it much better than any others means I am more productive, even though the other frameworks probably include nice little tricks and shortcuts, and because I know it better I can debug problems faster.
Basically what I am trying to say is that just about every popular web framework can do everything that you want it to. Some are better than others but what really matters is that you become an expert in at least one of them. Being able to dabble in lots is not helpful, you really need to know one inside and out. Committing some code to the project helps this process.
Mainly depends on which programming language you prefer to work and most comfortable with. Some prefer the flexible syntax of Ruby others like the cleanliness of Python. Also need to take into consideration the production environment (aka what OS is it going to be hosted on).
Django does not do interactive web applications, it is agnostic to the whole "frontend" part, this is done in Javascript with little to no support from Django (except for transferring data from AJAX calls).
So if you want to use Django for this, you will have not only to learn Python but also to learn loads of Javascript.
I like this solution as hand-written Javascript feels a lot clearer than any of these generating tools to me, plus there are plenty of libraries that make writing advanced Javascript GUIs a breeze these days, check out Jquery UI or ExtJS.
From there, the server side will only be AJAX calls that (de)serialize data in JSON, nothing else.
Both Rails and Django are good. Try them both out and see which you like better.

Best technology option for implementing RIA with Rails as the backend?

I'm working on a application that requires a feature-rich media view, including images, videos, and smooth sequencing based on capture time. The backend is currently written in Rails.
What's currently the best, most mature option for implementing RIAs with Rails on the backend? I've looked at Flex, Laszlo, and ExtJS. ExtJS is interesting to me because I'm really not a fan of pure Flash UIs, but it seems highly targeted towards business apps, not entertainment applications like this.
Any suggestions or insights from others doing similar efforts will be very much appreciated.
Thanks!
I second zdmytriv for that book Flexible Rails, it's awesome. It's fairly outdated now though but lays out how simple it is to create a solid Project Management application with Flex and Rails. Everything in there has now become "RestfulX".
Check out RestfulX, it's a must. The RestfulX Google Group is very active too and they've made a lot easy.
We built this website in Flex with RestfulX and it was very easy. That application uses the Rails Paperclip gem to do image processing in a Flex admin panel like ScrapBlog (Scrapblog was built in Flex), and we could use some cool layout effects built into Flex 4. RestfulX made that pretty easy, and the gems made it even easier :p. They have generators too like Rails so it's real easy to get up and running with a DataGrid/CMS-like interface in 5 minutes.
I don't know anything about the other things you've mentioned, but I do know that it's pretty fun and easy to integrate Flex with Rails now-a-days.
As a side note, you can do hardcore SEO with Flex and Rails too, thanks to SWFAddress. We're doing that with that site above.
Cheers
I can recommend Flex and also this book Flexible Rails, whole book dedicated Flex with Rail cooperation. List of sample applications from the book here
Flexible Rails http://ecx.images-amazon.com/images/I/51QysfVDlVL._SL500_AA240_.jpg
If you're serious about considering Ext as an option, you should really search and maybe post in their forums about others using Rails, I know there are quite a few doing so successfully. I just ran across this example that seems like a pretty fully-baked app doing just that, so it's definitely possible.
Without knowing exactly what you're trying to do, I think that saying Ext is "targeted towards business apps" is a fair general statement, in terms of the widgets that come with it out of the box. It's highly geared toward window/form-based Ajax apps. That said, Ext Core is very similar to jQuery and other core frameworks, and everything in Ext is built to be highly extensible (hence, "ext"). In terms of being able to build what you need off of it, it is very powerful and flexible. You can certainly implement a flash viewer easily, and there are existing plugins that will do exactly that.
Sounds like Toby had a bad experience with Ext, but many other people enjoy it and find it very natural to code in. The syntax definitely has a Java/C# flavor to it in some ways (although it's really hard to directly compare any JS framework to a static language), and it has roots in YUI (which is even more verbose). For someone coming from C-ish backgrounds, it will likely feel very comfortable. If you're more used to Python or Ruby or something else, then it might not be as enjoyable, I don't know. Something you'd have to try for yourself.
Take a look at WebOrb from themidnightcoders.com. Among many features, it allows for AMF protocol for serialization of data. It is smoking fast.
IMO, if you want a true RIA experience, you'll need to focus on either Flex or Silverlight. There are pros and cons to each.
I did a GWT project a while back and am working with Ext right now. I have some C# / Swing GUI experience, none in Flash.
I like Ext a lot. It looks great, and I found the programming model close enough to the C#'s and Swings of the world as to be familiar and fairly pleasant. The documentation is not excellent, but definitely good enough. For Java at least, there is a solid remoting mechanism (third party, called DJN... most likely there are others, too). A couple of minor bugs here and there.
The major negative is support. They have a forum but there are a distressingly large number of questions and problems that go unresolved. They have paid support in theory, but were sufficiently unresponsive to basic 'how does your paid support work' type questions that I was not encouraged to buy any. There is only one book that I know of, it looks promising but it is not out yet.
I found GWT impressive and had no real problems, but at the end of of the day I am much happier with Ext.
Have you taken a look at Google Web Toolkit yet? In my opinion it's a great way to build rich and performant web applications. The toolkit is quite mature (Google Wave is build with it) and has a lot of good tools to make development easy.
Here's a previous Stakoverflow post.
I don't know about best, but I did a project using ExtJS and hated every minute of it. Frustratingly verbose code, overly complicated programming model, confusing documentation, and difficult to make it do anything it didn't want to.
That said, it looks very awesome, has incredibly powerful widgets and the client and users loved it.
I haven't helped at all, have I?
I think if you requirements include doing anything with video and audio, you are going to need a Flash solution.
Take a look at netzke -- client-server components with Sencha Ext JS and Ruby on Rails.
Netzke is a framework that allows for a beautiful blend of client- and
server-side code (JavaScript and Ruby, respectively) into ready-to-use
GUI components. It's most useful for creating complex data-rich
backend applications with Ruby on Rails on the back end, and Sencha
Ext JS in the browser.

Should I re-write the webapp front end in Erlang?

I have a Rails webapp [deployed on Heroku] which makes a series of HTTP calls to other sites on a repeated basis, using Heroku's rake:cron feature. The current situation isn't ideal; the rake:cron process is executed in a single thread, which means HTTP calls are made sequentially; which means in turn that there's a long time between calls to the same site [typically 2 mins].
I'd like to execute this process in parallel, and reduce the time between calls to 10 secs. Having seen Kevin Smith's 'Erlang in Practice' I'm sold on the idea of using Erlang as a replacement backend. What I'm trying to figure out [given Damien Katz's comments], is whether I should a) re-write the entire webapp in Erlang, front end and all or b) maintain a split structure, with a Rails frontend / Erlang backend.
I like the idea of using a 100% Erlang stack for the project; I'll need to use some kind of Erlang web framework [Nitrogen ? Erlyweb ?]; I'm concerned they're not mature enough and I'll spend my time bogged down on the web part of the project with them.
Anyone any views ? Thanks.
What's the actual impact on your visitors (of the two-minute interval between HTTP backend calls)?
If there isn't much of a difference, I'd say this sounds like premature optimization and that you'd be much better off skipping Erlang for now.
The two previous posters have pretty much covered they philosophical aspects of your question. So I'll answer the framework maturity/getting bogged down part of your question.
In the event that you decide you do want to rewrite the webapp in erlang for whatever reason then I wouldn't be too concerned about the framework slowing you down. Both erlyweb and nitrogen are already feature complete enough that you can work pretty quickly with them. I've developed a fairly complex agile project management app in nitrogen and found it to be quite intuitive and not really lacking in features that I needed. A few hours in the evenings and a few weeks later and I had a working app up and running.
As to which one to use that depends on the type of app you want to build.
Nitrogen's target is extremely dyamic web applications. Most of the page is rendered using javascript and it is highly event driven.
ErlyWeb is more suited to a site where the content is the primary focus less so than a rich client type of application. It uses the MVC style of architecure.
Good luck on whatever you decide.
It depends. How much Erlang do you know? How much code have you already written?
How much project experience do you have? Is this for work or for fun?
Rewriting projects from scratch is often a recipe for disaster, especially if you are trying
to learn a new language along the way. It seems to me like you would not be asking this question if you were already fluent in both languages, in which case I would recommend that you just stick to Ruby if it's a work project.
I disagree with the above poster that changing the language is a premature optimization, if it is necessary.
Changing the language is a big deal. It can't be done at the last minute.
However, I would probably not change the language at all for the reason you outlined.
If you don't have any other reasons than performance for switching, you should probably just
look at multi-threading in Ruby or some other optimization.
I'm all about using the right tool for the job. Unless you have an absolutely dead on reason to port the front, there's absolutely nothing wrong with hooking the two together.

Best practices for refactoring classic ASP?

I've got to do some significant development in a large, old, spaghetti-ridden ASP system. I've been away from ASP for a long time, focusing my energies on Rails development.
One basic step I've taken is to refactor pages into subs and functions with meaningful names, so that at least it's easy to understand # the top of the file what's generally going on.
Is there a worthwhile MVC framework for ASP? Or a best practice at how to at least get business logic out of the views? (I remember doing a lot of includes back in the day -- is that still the way to do it?)
I'd love to get some unit testing going for business logic too, but maybe I'm asking too much?
Update:
There are over 200 ASP scripts in the project, some thousands of lines long ;) UGH!
We may opt for the "big rewrite" but until then, when I'm in changing a page, I want to spend a little extra time cleaning up the spaghetti.
Assumptions
The documentation for the Classic ASP system is rather light.
Management is not looking for a rewrite.
Since you have been doing ruby on rails, your (VB/C#) ASP.NET is passable at best.
My experience
I too inherited a classic ASP system that was slapped together willy-nilly by ex excel-vba types. There was a lot of this stuff <font size=3>crap</font> (and sometimes missing closing tags; Argggh!). Over the course of 2.5 years I added a security system, a common library, CSS+XHTML and was able to coerce the thing to validate xhtml1.1 (sans proper mime type, unfortunately) and built a fairly robust and ajaxy reporting system that's being used daily by 80 users.
I used jEdit, with cTags (as mentioned by jamting above), and a bunch of other plugins.
My Advice
Try to create a master include file from which to import all the stuff that's commonly used. Stuff like login/logout, database access, web services, javascript libs, etc.
Do use classes. They are ultra-primitive (no inheritance) but as jamting said, they can be convenient.
Indent the scripts properly.
Comment
Write an external architecture document. I personally use LyX, because it's brain-dead to produce a nicely formatted pdf, but you can use whatever you like. If you use a wiki, get the graphviz add-in installed and use it. It's super easy to make quick diagrams that can be easily modified.
Since I have no idea how substantial the enhancements need to be, I suggest having a good high-level to mid-level architecture document will be quite useful in planning the enhancements.
On the business logic unit tests, the only thing I found that works is setting up an xml-rpc listener in asp that imports the main library and exposes the functions (not subroutines though) in any of the main library's sub-includes, and then build, separately, a unit test system in a language with better support for the stuff that calls the ASP functions through xml-rpc. I use python, but I think Ruby should do the trick. (Does that make sense?). The cool thing is that the person writing the unit-test part of the software does not need to even look at the ASP code, as long as they have decent descriptions of the functions to call, so they can be someone beside you.
There is a project called aspunit at sourceforge but the last release was in 2004 and it's marked as inactive. Never used it but it's pure vbscript. A cursory look at the code tells me it looks like the authors knew what they were doing.
Finally, if you need help, I have some availability to do contract telecommuting work (maybe 8 hours/week max). Follow the link trail for contact info.
Good luck! HTH.
Since a complete rewrite of a working system can be very dangerous i can only give you a small tip: Set up exuberant tags, ctags, on your project. This way you can jump to the definition of a function and sub easy, which i think helps a lot.
On separating logic from "views". VBScript supports som kind of OO with classes. I tend to write classes which do the logic which I include on the asp-page which acts as a "view". Then i hook together the view with the class like Username: <%= MyAccount.UserName %>. The MyAccount class can also have methods like: MyAccount.Login() and so on.
Kind of primitive, but at least you can capsulate some code and hide it from the HTML.
My advice would be to carry on refactoring, classic ASP supports classes, so you should be able to move all everything but the display code into included ASP files which just contain classes.
See this article of details of moving from old fashioned asp towards ASP.NET
Refactoring ASP
Regarding a future direction, I wouldn't aim for ASP.NET web forms, instead I'd go for Microsoft's new MVC framework an add-on to of ASP.NET) It will be much simpler migrating to this from classic ASP.
I use ASPUnit for unit testing some of our classic ASP and find it to be helpful. It may be old, but so is ASP. It's simple, but it does work and you can customize or extend it if necessary.
I've also found Working Effectively with Legacy Code by Michael Feathers to be a helpful guide for finding ways to get some of that old code under test.
Include files can help as long as you keep it simple. At one point I tried creating an include for each class and that didn't work out too well. I like having a couple main includes with common business logic, and for complicated pages sometimes an include with logic for each of those pages. I suppose you could do MVC with a similar setup.
Is there any chance you could move from ASP to ASP.Net? Or are you looking at keeping it in classic ASP, but just cleaning it up. If at all possible, I would recommend moving as much as possible moving to .Net. It looks like you may be rewriting/reorganizing a lot of code anyway, so moving to .Net may not be a lot of extra effort.
Presumably someone else wrote most or all of the system that you're now maintaining. Look for the usual bad habits (repeated code, variables that are too widely scoped, nested if statements, etc.), and refactor as you would any other language. Keep an eye out for recurring things in the same file or different files and abstract them into functions.
If the code was written/maintained by various people, there might be some issues with inconsistent coding style. I find that bringing the code back into line makes it easier to see things that can be refactored.
"Thousands of lines long" makes me suspicious that there may also be situations where loosely-related things are being displayed on the same page. There again, you want to abstract them into separate subroutines.
Eventually you want to be writing objects to help encapsulate stuff like database connectivity, but it will be a while before you get there.
This is very old, but couldn't resist adding my two cents. If you must rewrite, and must continue to use classic ASP:
use JScript! much more powerful, you get inheritance, and there some good side benefits like using the same methods for server-side validation as you use for client-side
you can absolutely do MVC - I wrote an MVC framework, and it was not that many lines of code
you can also generate your model classes automatically with a bit of work. I have some code for this that worked quite well
make sure you are doing parameterized queries, and always returning disconnected recordsets
Software Development Project Management practices indicates that softwares like this are requiring to retire.
I know how hard it is to do the right thing, even more when the responsible manager knows sht and is scared of everything other than the wost way possible.
But still. It's necessary to start working on the development of a new software. It's simply impossible to maintain this one forever, and the loger they wait for retiring it the worse.
If you don't have proper specification/requirements documentation (I think no asp software in the world does, given the noobatry hability of those coders), you'll need both a group of users that know the software features and a manager to be responsible for validating the requirements. You'll need to review every feature and document its requirements.
During that process you'll go learning more about the software and its business. Once you have enough info, you can start developing a new one.

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