How does a client/server framework work - ruby-on-rails

I am confused about the current framework for a client/server architecture system.
You know, when we are writing a small demo, on the server side, we listen on a port and establish a TCP/UDP connection with client, after that, we do some customize work.
Well, my question is, when we are using a framework like Ruby on Rails, where can I put my customize work?
It seems these frameworks are just for people managing a website.
I can't add a comment, so some words more here.
Thanks for your answers. Actually, I know how to do socket programming to handle all the requrest. But since what I want to build is a product not a demo. I think a wide-used framework is what I need.
ACE and twisted seem good to do these things. But what about RoR? I saw many websites that you can use their APIs and get messages from their servers. Can't RoR do these things? If so, how can I implement HTTP + JSON communication between client and server without having a website page?
I checked several tutorials on RoR, they only told me how to build a website to present HTML files, but what I need is a mechanic to communicate between Server and Client.
Thank you.

Ruby on Rails is indeed designed for implementing a website or other HTTP-related things.
There are other frameworks out there for doing more generic server implementations. For example: ACE and Twisted.

Not sure I understand exactly what you're asking but it seems like you're looking for the Ruby sockets framework?
http://www.tutorialspoint.com/ruby/ruby_socket_programming.htm
Is a pretty straightforward description of how to do basic port listening/reacting.

I assume you are looking for an explanation of where cusom code goes when the server is mostly built from reusable pieces coming from a framework.
Forgetting about Rails for now, many older, simpler frameworks started life as a simple way to build objects to represent the incoming request and the outgoing response on the server side. From there, your custom code would be in making decisions about what to do with the request, and what to write to the response.
A more complex framework may include a templating engine, which makes it easier to put a complete response together by filling in the blanks (like a user name) in an HTML template, avoiding the need to manually craft the whole HTML response in the server code.
A lot of modern frameworks allow you to write applications like this, and many provide other pieces of functionality to make common coding patterns quicker and easier to write.

Related

Client side MVC instead of server side MVC

Instead of using server side MVC like Ruby, Python, PHP to build very complex websites, why should not we split our website into multiple modules, and build each with client side MVC like backboneJS, EmberJS. In this case, we will use PHP / Ruby for creating webservices alone, which will serve data only.
Each module now act as small web app. If we link each other, they will perfectly look like a complex web app.
I visit many websites (like github, groupon, stackoverflow etc...) and they can be built or adopted to this approach. But i am not seeing this kind of approach. Does this approach has any problem on this kind of websites?
Was to long for a comment
I guess the tricky part is indeed the point you mentioned
f we link each other, they will perfectly look like a complex web app.
Because each MVC framework uses a different approach to tackle usual problems you have in modern web-apps, like routing, data binding, application state and rendering DOM elements, so I think you would end up having multiple frameworks doing tasks that overlap substantially, thus forcing you to deactivate or disable some of the built-in functionality of one or the other framework making your frankenstein-app :) very difficult to maintain.
A good example is jQuery-mobile & ember.js, both have a routing system, jQuery uses the DOM to hold state ember.js holds it's state completely in javascript which is much faster. I had a similar problem with a project using jQuery-mobile & ember.js and this forced me to decide for one of the routing systems, I took ember's and deactivated jQuery's wich then let with just a bunch of custom mobile-looking components on the side of jQuery-mobile. Finally I removed jQuery-mobile using ember.js only and CSS for the mobile-looking app.
If not because of a concrete requirement, IMHO your best bet is to have just one very good, flexible and opinionated framework (personally I prefer ember.js) and create the modules you mentioned with your only choice.
Hope it helps.
As of now we can say that most of the applications are forced to put in more effort in its UI/UX and hence the dependancy on server side is becoming very less.
I have personally used backbone for my latest work and this has been great. The speed of the entire application can be noticed from the beginning. Ive been using PHP for the past 3 years and i can definitely vouch that backbone and other MV* frameworks are better.
Combined with CSS frameworks such as bootstrap, backbone can be an extremely organised and elegant applications.
All said, getting your head around models,views,routers,collections can be a headache. This is something which has vast possibilities and its only getting started.
Ive compiled a tutorial based on lots of tutorials present and has published at http://goo.gl/nJumC.
So many video tutorials are also available.
Only per-requisite is that one should have good knowledge of javascript and jquery methods and functions. Beginner knowledge in these will only make your task of learning backbone difficult.
Oh yes. I got my answer.
From google groups:
I think one of the reasons is javascriptless user-agents — i.e. search
engine crawlers and users with NoScript turned on.
I hope, these are real problems why websites still using Server Side MVCs.
When websites don't know target audience, they can't predict how well it will run on client side. So they should rely server to build much of their content.
And think, if stackoverflow was designed using client side MVC's to build much thier content, no one can't reach stackoverflow posts using google search.
From wikipedia under "Search engine optimization" section:
Because of the lack of JavaScript execution on crawlers of all popular
Web search engines, SEO has historically presented a problem for
public facing websites wishing to adopt the SPA model.
I think that is the shift we are heading now; I am not really sure about you but I noticed far more Client Side MVC Web sites. Anyways, you can also take a look at this ....
http://backbonejs.org/#examples
in my view, except the learning curve, it is pretty neat to develop using Client MVC and Web APIs using JSON/REST

Building the back-end server for an iPhone App

I'm looking at building a simple login-based iOS application that needs secure access to create, read, updated and delete data from a MySQL database - with certain actions available to specific users based on roles.
I've done some research and it looks like I need to build a RESTful Web service which provides Web Services which the iPhone app calls to access the data.
I have very little experience of web services development, are there any books/tutorials that are worth checking out? Is it worth looking at a web framework, rather than start from sractch?
I've done some basic web development in PHP/Python so would prefer to build in that I think..given that hosting it would be relatively cheap..
Have done some basic C#/Java; would it be worth looking at these instead? I tried creating a simple ASMX webservice but most of the examples cite using a MSSQL server, not sure if that is the way to go though.
Use a framework. No point reinventing the wheel and giving yourself a headache. A good PHP based solution would be to use Drupal to build the backend using the Services module to provide data via webservices. Drupal is so flexible and so popular now, that you can get a lot of what you want done without any code at all.
Roughly:
Install Drupal 7 on a webserver according to the instructions
Install the Services module
Design the entities that will make up your MySQL database
Tell the services module how you want to expose things
Some examples of API calls are here.
A case study of someone else who has used Drupal as the backend for iPhone/Android is here.
You will have a learning curve to get your head round Drupal, but you'll have one anyway to get your head around webservices and the benefits you gain from having everything else Drupal offers are enormous, e.g.
The difficult bits are already done for you, so the amount of code will be massively reduced, if you even need any at all
Using Drupal's hugely flexible entities system, you can design a flexible and extensible mysql database scheme using the web based UI, which will be ready to work with any of Drupal's other modules, so you can expand add features with minimal effort in the future
There's an enormous community of people who can help you and the forums on drupal.org are very active
You would have a great UI for users, in case you ever need to give them access to their data through a normal website interface. Drupal has loads of pre-built themes (I recommend Omega) which look awesome and again, little to no code is needed to get a whole site ready made along with HTML5, standards compliance etc.
Drupal provides you with ready-made modules to provide access control via roles, as well as everything else you can imagine e.g. managing a mailing list for your users, providing you with usage statistics, admin interface for user and role management etc.
Drupal use is exploding globally and there's a serious skills shortage, so you'd be even more employable :)
First, it's not compulsory that you use a REST web service. It's just that WS si more or less standard for web-based applications.
I'm not really familiar with PHP, but in python you have django-piston. On the IOS side you have restkit to pair the server with.
What I could say from my experience is that writing a prototype in django is quite easy and you can definitely use this to develop your app.

Combining Ruby on Rails and Backbone

I was wondering this for quite a while and haven't really found an answer for this yet.
Why would you use Backbone.js exaclty inside a Rails application? Is it to extend functionality, have a more MVC pattern for your JS, build better API's...?
At the moment I can't see a reason why you would want to use it for something, because I don't think I understand the concept of Backbone.js
The big advantage of rails is that you have one platform and one language that you use that will handle the server-code and can generate the client-code (using the views).
Undoubtedly this theoretical advantage quickly starts slipping once you want to improve your user-experience with javascript and jquery. So actually you still have to learn two languages.
But still: all your models, business-rules, ... is handled on the server-side in Ruby. This also means that the server always has to be reachable.
What a javacript/client MVC (like Backbone.js, Sproutcore, ...) can offer you is a more native application feel. A single web-page application, like e.g. Gmail.
Depending on your requirements there are some very valid use-cases for such a platform. E.g. in places or devices with low connectivity it could be very useful (with HTML5) to have a web-application that does not need to be "online" all the time. It could save data and edits to the local storage and sync back to the server/database when the device is back online.
But, there is a big disadvantage when developing client MVC applications in combination with Rails: you will have to do some double development (it is the same when you are using flex/silverlight). Your models will need to be defined both on the server and on the client. I can imagine that some improvements could be made, like on the client MVC you are actually using presenter-classes, which on the server-side could be stored in different models/tables. But still there will be duplication of logic, models, ...
So that's why I think that for most applications, at the moment, it is not wise to switch to some client MVC framework. It will be a lot more work.
But when you do need the look and feel of a real native application, or a one-page-web application, then a javascript client MVC framework is the way to go. And if you do need a client MVC framework, I would propose Sproutcore.
To simply ajaxify your current rails application (reduces load-time of every single page), take a look at pjax-rails.
(better late than never - hope this is useful to someone)
The description on backbonejs's website seems like a lot of words thrown together without much meaning. There is a big hype around it but what's all the fuss about?
The premise behind backbone is that modern day, single page web apps (think gmail) quickly become a very complex interaction between syncing dom elements, UI events and the backend. You could easily find yourself storing data within the dom elements, and then having to somehow extract the data again to update the database. If you don't structure your code very carefully, you'll quickly end up with spaghetti code full of complex bindings, or code without backbone.
Using backbone's models, collections and views gives you a well thought out structure to work within, allowing you to build large apps without being overwhelmed by their complexity. What's more, it ties in beautifully with a restful backend.

Which framework offers similar functionalities to ADO.NET Data services

I am new to both Django and Rails. I am thinking of developing an Web 2.0 style application and is planning to expose Restful services, which my UI tier would call to make CRUD operations (Something similar to ADO.NET Data services)
I am yet to decide on the platforms and is looking for some advice on which one to side develop on?
I am currently thinking of Ruby on Rails or Django.
The benefit of using DJango / Python is that I can move to google AppEngine in future with some code changes, but on the down side I hear DJango is not RESTful.
I am also new to both Ruby and Python. So, what would be your advice on which platform to use?
Well if you want to couple the view and controller with REST then you are right that django is not RESTful, because with django you would have to (de)serialize django objects and manipulate that by yourself in the front end using your favourite javascript framework. Saying that, if your only concern is to send and receive data RESTfully without caring how to do it, then django should be sufficient for you since you've already got your heart for it.
Django is fine for REST applications. Rails claims to provide some functionality to that makes REST easier, but it is largely inaccurate - things like human-readable URIs don't really matter to REST. Rails auto-generates POST/GET/DELETE/PUT stuff for you, but it's just as easy to do in Django too - and it really doesn't have much to do with REST, either, it's just proper HTTP usage.
REST is a general type of architecture, it has very clear constraints, but there is no one, single way to do a REST application. This is a good discussion by the architect of REST, Roy Fielding, on some common misconceptions: http://roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven
I recommend Python and Django, but not for REST-related reasons. (Better documentation, a saner API with Django, less nasty monkey patching and black magic, less coupling, etc)
A RESTful interface is used for building distributed applications. Does your UI tier and services tier really need to be physically separated? Seems overkill to me.

Rails and Flex to build an RIA

Any thoughts on using Flex to build an RIA for administering a complex rails app?
We are starting to find it difficult using ajax to keep our admin section intuitive and easy for users to work with.
You've got RoR guys working on this program and you've managed to develop a complex rails app that has enough subtleties that the admin section is difficult to use.
The answer to this problem is not to use a different programming language to create a whole nother kinda app to do the admin.
It will help more to get assistance in simplifying and organizing your admin section. Work through some paper sketches to get a better idea of how to present this complexity and maybe reveal complexity as you go along.
Complexity is handled often by using wizards or revealing suboptions as you go along. Spend some time with your users and watch them do their tasks.
With more details I could edit this answer with more specifics.
Try investigating this book:
Flex is certainly worth considering in your scenario. Generally, Flex is more mature development platform than AJAX is so if your server-side data are exposed via some reasonable interface (web services, REST-full services etc.), building a Flex front-end would make sense.
It really depends on your needs - Flex vs. AJAX is an interesting topic on its own.
If you want to use XML for communication then there isn't much you need to do on the rails side. But if you want to use an AMF gateway you will want to checkout RubyAMF.
But I agree with MattK if you just want to redesign your admin section it's not worth adding in Flex. I think you just need to do some usability testing, take that feedback and refractor your interface.
I would only consider using Flex in your situation if you already have Flex developers or if you could outsource that part of your project. The Flex modules simply call web services (written in Ruby or whatever) so there is a very nice separation between the two parts of your project. Since the interface between the two parts is an easily-mockable web service, outsourcing works well. There should be plenty of web shops local to you who could handle the work. An admin site should take only two to three weeks to develop in Flex if the developers are knowledgeable.

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