Is it possible to avoid following the MVC pattern while using Rails? - ruby-on-rails

Some of the responses to a question I asked today earlier today have caused me to question my assumption that it should be possible to use Rails in a non-MVC manner as opposed to simply using a microframework like Sinatra for barebones non-MVC-type apps.
Has anyone used Rails in a non-MVC manner without it causing major problems or could you imagine an appropriate case for doing so?

What do you want to build? If you want to use all of rails, MVC is the way to go. Even a tiny framework like camping is MVC.
If you just need a part of it, most commonly, activerecord, you can happily use it any way you want.
But rails itself is MVC all the way, you'd be working against it trying to coerce it into another paradigm.

Yes, it is possible, but Rails framework architects made it difficult to stray from the MVC path for a reason. They want to encourage 'good' behavior and discourage 'bad' behavior.

Not only should you use MVC with Rails, but MVC is a good idea in general.
If you're just writing some one-off-ish app then you might look at Rails Metal or, as you already mentioned, Sinatra.

Again, why do you WANT to avoid MVC? MVC is an excellent thing

Related

Justification for MVC?

I was wondering if someone could provide me with some answers. I've been asking to swap our internal apps to an MVC architecture for quite a while now. Rails was absolutely shot-down as a toy, Struts is just too huge for the apps we do, Django's name makes these old folks nervous (oil & gas industry) but finally, finally Microsoft has come out with MVC 1.0.
Since the Powers that Be are dead-set on using Microsoft technologies, I think I may be able to convince them to move our applications to an MVC pattern. Unfortunately, I can't come up with a good reason to swap to our forms-based structure to an MVC style.
Can anyone think of justification good enough to feed to my bosses? :-)
Do you have a good reason to switch? It sounds like you don't so I am wondering if you are switching for the sake of MVC itself which I would discourage you from doing.
ASP.NET MVC is helpful when you wish to have more control over the output and lifecyle of your application. Keep in mind that in many cases this means more work for you as the developer. MVC frameworks are good for sites that are not data-entry intensive - in other words if you handle a lot of form POSTs and process data out of those forms then ASP.NET MVC will actually create more work for you.
I don't mean to sound harsh but it seem strange to me that you want to switch to ASP.NET MVC but don't really know why.
There are a number of questions that address this in different ways:
Should I pursue ASP.NET WebForms or ASP.NET MVC
How to decide which is right, WebForms or MVC when doing ASP.NET
Traditional ASP .NET vs MVC
Biggest advantage to using ASP.Net MVC vs web forms
MVC Versus Web Forms
ASP.NET vs ASP.NET MVC
I think it's not a matter of "selling" MVC, but rather of understanding it's advantages.
also, you should seriously evaluate whether migrating an existing system to MVC will be cost effective.
however, MVC has many advantages - here are some from the top of my head:
separating control, data and presentation makes your application more maintainable
easier to make changes
after a relatively short learning curve, easier for other programmers to comprehend
better design means introducing new features is easier. try adding caching, form validation, etc when everything is mixed up...
an MVC system may be more testable (and therefor can be more reliable) - it's much easier to test your controllers than to test a spaghetti of data, control and presentation code.
I think that in this case the OP is looking for a pragmatic (profitable) reason to switch over to MVC, since most companies think that way.
The biggest advantage is that it is much easier to create unit tests for ASP.NET MVC applications. A good suite of unit tests can then serve as the foundation of a Continuous Integration process.
The bottomline for the powers to be is that you can create a build in a single step, simplifying deployment, creating installers, patches etc.
Rails and Django both follow the Model View Controller (MVC) pattern so sounds like you will just be creating a load of work for yourself. Why do YOU want to switch to ASP.NET MVC?
"Struts is just too huge for the apps we do"
In what way? Struts made even simple internal applications a breeze to develop in our company, once we had learned how it worked (which was quite quick). A few JSPs, a few Actions, backend database access done in JDBC via some simple DAOs, bundle it all up in a war with ant/maven and deploy. Done.
Also, fyi, keep Joel's advice in mind (Things You Should Never Do, Part I): avoid rewrite the code from scratch.

Should I use .erb or .rhtml files for a Rails app in which all Controller logic exists in Views?

I'm just starting to learn Rails. I created an empty Rails app. And instead of writing a Controller, I want to put all of my Controller logic in my Views instead of in separate Controller classes.
To do this, should I use .erb files or .rhtml files and what's the difference?
First of all, they are virtually the same thing but you should use the new standard naming format of .html.erb
Second of all, stop what you are doing and reconsider everything!!!!!
The whole point of MVC is to separate logic from display and vice versa. Most of your logic should be in your models and the controller should just facilitate grabbing that logic and passing it to your views.
You should not do anything in your views other than display the data.
"A client has asked me to build and install a custom shelving system. I'm at the point where I need to nail it, but I'm not sure what to use to pound the nails in.
Should I use an old shoe or a glass bottle?
In your case I'd go for the glass bottle.
In the new rails 3.0 .rhtml files will be unsupported. .html.erb is the new standard.
I understand that you have a small app and standards don't really apply to you, but that is the whole point of MVC. The logic should go into the controller/model and the view is strictly for presentation.
The simple answer to your question is no. No you shouldn't put controller logic in the views. If you don't need controllers then you probably don't need rails. I know that's not the answer you want, but frankly you are wrong, pure and simple. If you want to learn the Rails framework, then what you have been told here is correct and to do it your way would simply then mean either unlearning what you just did or it would mean becoming a bad developer.
That's the way it is, the rest is now up to you.
Yes, you are correct in that the creators of rails never stated that you should not use rails for smaller apps, but they have stated over and over the importance of the controller.
I created an empty Rails app. And instead of writing a Controller, I want to put all of my Controller logic in my Views instead of in separate Controller classes.
Just out of curiosity, what type of logic are you considering putting into your views? If it is presentation logic then that is one thing but if it is business rules, loading data from a database, xml file, web service/rest based then you are violating the core principles of rails. Ever heard of ASP (Classic Active Server Pages)? Frameworks have evolved beyond that to overcome the shortcomings and pitfalls like ASP to allow you not to mix presentation and code. If you jam it all together, how will you unit test your code? Another key principle of rails that is why it is built into the framework itself unlike other web frameworks.
I want to learn how to use the "standard" Ruby framework
In your responses you keep mentioning you want to learn the standard Ruby framework? If this is the case why don't you use irb then? Rails is not part of the standard Ruby framework. In fact you will probably learn a lot more about Ruby using irb then you will Rails. Once you have familiarized yourself with Ruby then take on rails.
I agree with the others and if you are going to take the time to learn a framework, then learn it right and as the creator intended, otherwise you are missing the point and you will not see why rails is such a good web framework to begin with. What you are hoping to accomplish can be done in a number of web technologies: ASP, ASP.Net, PHP, JSP, Perl, but you choose to learn Ruby and rails therefore do not do it the same as you could in any of the other web technologies.
Adhering to MVC is the way to proceed to build an application.
If you are uncertain why Controller is needed then do the research. I have
faced maintaining code where the scrips are embedded in the presentation layer.
It is farcical to begin any engineering effort without a thorough understanding
of the correct, time tested methodology. It is like trying to build a house
using no foundation or blueprint.
Nothing, really. It’s just a change of philosophy between Rails 1 and Rails 2. Before Rails 2, you had file.rhtml, file.rxml and file.rjs. In Rails, that changed to file.content_type.template_engine. So with file.html.erb, the content type is html and the template engine is ERb. rxml is now xml.builder and rjs should now (mostly) be js.rjs
In the new rails 3.0 .rhtml files will be unsupported. .html.erb is the new standard.

WebForms to MVC conversion

I've got a pretty simple site (around 8 pages) with only one way page containing any significant codebehind, and I'd like to try learning MVC, using it as the test.
Is it best to start a new MVC Web App from scratch and cut-and-paste the HTML in, or will it be easier to retool the existing files.
Basically, what am I in for? What's it gonna take to get my Web Forms app into the MVC model? What approach should I take? Create the default MVC web app and start cutting-and-pasting? Add the appropriate namespaces and learn to setup the MVC structure myself?
Unlike tvanfosson, I think you will actually learn more about MVC by trying to translate your existing application. You'll learn which assemblies to add, you'll work out how to associate the right http handlers, you'll learn what the correct web.config settings are, and you'll know which dependencies to remove from your web application to get it to work.
To be honest, it will feel harder doing it this way and be a little more frustrating, but at the end of the process you will know a hell of a lot more than just starting a new one from scratch. Good luck with it.
You'll want to start from a project template in a new project. Transfer your markup to your new views as needed, although it's more likely that you'll just be using the old site as a design template than actually reusing code. You'll find that MVC is much different than WebForms.
I don't think retooling the existing Web Forms application is the best approach (or even feasible). As you will surely discover, the differences between Web Forms and MVC are quite big. So, starting from scratch (although you can recycle the html) will most likely be the better approach and the best way to learn as much as possible about MVC.

Migrating web application to asp.net mvc

I need your advice regarding migration. I want to migrate existing project to ASP.NET MVC and I can figure out the proccess except of url rewriting issue:
for example how can I make following route:
http://www.eireads.com/ireland/mayo/cars-3/1263-used-cars-citroen-c5-for-sale.aspx
Or maybe I could somehow keep supporting legacy routes.
I think that migrating a web forms applicaiton to MVC is going to be very hard unless you have a clear seperation of concerns in your current applicaiton. If you have followed a design pattern like MVP then it might be easier, but if not then much of your business logic is likey going to have to be moved to controller classes and much of it re-written.
I would start by extracting your model, this should be fairly easy, then identifying your controllers and actions and seeing how much code you can re-use. At this point you should be able to discern whether or not you can migrate or if you'll be better off re-writing portions of your applicaiton.
Default URL patterns in ASP.NET MVC are http(s)://(appdomain)/(controller)/(action)/(par/ame/ters)
So your url above should fit into that pattern. You can change the pattern to account for other things (like namespace for example). Your URL pattern might be:
http://www.eireads.com/cars/used/ireland/mayo/citreon
where ireland, mayo and citreon are the in put parameters.
I think you should really re-write your question and try to detail exactly what you are attempting to accomplish here.
If you are asking how to migrate an existing WebForm project into ASP.NET MVC keeping the same URL rewrite, the answer is; not easily. The models are too different.
Yet, you mention "routes" in the end, which make me think you are speaking like those of the System.Web.Routing namespace. So are you dealing with an existing MVC app and want it too look like that URL path? I can't tell. I am confused.

Should I migrate to ASP.NET MVC?

I just listened to the StackOverflow team's 17th podcast, and they talked so highly of ASP.NET MVC that I decided to check it out.
But first, I want to be sure it's worth it. I already created a base web application (for other developers to build on) for a project that's starting in a few days and wanted to know, based on your experience, if I should take the time to learn the basics of MVC and re-create the base web application with this model.
Are there really big pros that'd make it worthwhile?
EDIT: It's not an existing project, it's a project about to start, so if I'm going to do it it should be now...
I just found this
It does not, however, use the existing post-back model for interactions back to the server. Instead, you'll route all end-user interactions to a Controller class instead - which helps ensure clean separation of concerns and testability (it also means no viewstate or page lifecycle with MVC based views).
How would that work? No viewstate? No events?
If you are quite happy with WebForms today, then maybe ASP.NET MVC isn't for you.
I have been frustrated with WebForms for a really long time. I'm definitely not alone here. The smart-client, stateful abstraction over the web breaks down severely in complex scenarios. I happen to love HTML, Javascript, and CSS. WebForms tries to hide that from me. It also has some really complex solutions to problems that are really not that complex. Webforms is also inherently difficult to test, and while you can use MVP, it's not a great solution for a web environment...(compared to MVC).
MVC will appeal to you if...
- you want more control over your HTML
- want a seamless ajax experience like every other platform has
- want testability through-and-through
- want meaningful URLs
- HATE dealing with postback & viewstate issues
And as for the framework being Preview 5, it is quite stable, the design is mostly there, and upgrading is not difficult. I started an app on Preview 1 and have upgraded within a few hours of the newest preview being available.
It's important to keep in mind that MVC and WebForms are not competing, and one is not better than the other. They are simply different tools. Most people seem to approach MVC vs WebForms as "one must be a better hammer than the other". That is wrong. One is a hammer, the other is a screwdriver. Both are used in the process of putting things together, but have different strengths and weaknesses.
If one left you with a bad taste, you were probably trying to use a screwdriver to pound a nail. Certain problems are cumbersome with WebForms that become elegant and simple with MVC, and vice-versa.
I have used ASP.NET MVC (I even wrote a HTTPModule that lets you define the routes in web.config), and I still get a bitter taste in my mouth about it.
It seems like a giant step backwards in organization and productivity. Maybe its not for some, but I've got webforms figured out, and they present no challenge to me as far as making them maintainable.
That, and I don't endorse the current "TEST EVERYTHING" fad...
ASP.NET MVC basically allows you to separate the responsibility of different sections of the code. This enable you to test your application. You can test your Views, Routes etc. It also does speed up the application since now there is no ViewState or Postback.
BUT, there are also disadvantages. Since, you are no using WebForms you cannot use any ASP.NET control. It means if you want to create a GridView you will be running a for loop and create the table manually. If you want to use the ASP.NET Wizard in MVC then you will have to create on your own.
It is a nice framework if you are sick and tired of ASP.NET webform and want to perform everything on your own. But you need to keep in mind that would you benefit from creating all the stuff again or not?
In general I prefer Webforms framework due to the rich suite of controls and the automatic plumbing.
I would create a test site first, and see what the team thinks, but for me I wouldn't go back to WebForms after using MVC.
Some people don't like code mixed with HTML, and I can understand that, but I far prefer the flexibility over things like Page Lifecycle, rendering HTML and biggy for me - no viewstate cruft embedded in the page source.
Some people prefer MVC for better testibility, but personally most of my code is in the middle layer and easily tested anyway...
#Juan Manuel Did you ever work in classic ASP? When you had to program all of your own events and "viewstatish" items (like a dropdown recalling its selected value after form submission)?
If so, then ASP.NET MVC will not feel that awkward off the bat. I would check out Rob Conery's Awesome Series "MVC Storefront" where he has been walking through the framework and building each expected component for a storefront site. It's really impressive and easy to follow along (catching up is tough because Rob has been reall active and posted A LOT in that series).
Personally, and quite contrary to Jeff Atwood's feelings on the topic, I rather liked the webform model. It was totally different than the vbscript/classic ASP days for sure but keeping viewstate in check and writing your own CSS friendly controls was enjoyable, actually.
Then again, note that I said "liked". ASP.NET MVC is really awesome and more alike other web technologies out there. It certainly is easier to shift from ASP.NET MVC to RAILS if you like to or need to work on multiple platforms. And while, yes, it is very stable obviously (this very site), if your company disallows "beta" software of any color; implementing it into production at the this time might be an issue.
#Jonathan Holland I saw that you were voted down, but that is a VERY VALID point. I have been reading some posts around the intertubes where people seem to be confusing ASP.NET MVC the framework and MVC the pattern.
MVC in of itself is a DESIGN PATTERN. If all you are looking for is a "separation of concerns" then you can certainly achieve that with webforms. Personally, I am a big fan of the MVP pattern in a standard n-tier environment.
If you really want TOTAL control of your mark-up in the ASP.NET world, then MVC the ramework is for you.
If you are a professional ASP.NET developer, and have some time to spare on learning new stuff, I would certainly recommend that you spend some time trying out ASP.NET MVC. It may not be the solution to all your problems, and there are lots of projects that may benefit more from a traditional webform implementation, but while trying to figure out MVC you will certainly learn a lot, and it might bring up lots of ideas that you can apply on your job.
One good thing that I noticed while going through many blog posts and video tutorials while trying to develop a MVC pet-project is that most of them follow the current best practices (TDD, IoC, Dependency Injection, and to a lower extent POCO), plus a lot of JQuery to make the experience more interesting for the user, and that is stuff that I can apply on my current webform apps, and that I wasn't exposed in such depth before.
The ASP.NET MVC way of doing things is so different from webforms that it will shake up a bit your mind, and that for a developer is very good!
OTOH for a total beginner to web development I think MVC is definitely a better start because it offers a good design pattern out of the box and is closer to the way that the web really works (HTML is stateless, after all). On MVC you decide on every byte that goes back and forth on the wire (at least while you don't go crazy on html helpers). Once the guy gets that, he or she will be better equipped to move to the "artificial" facilities provided by ASP.NET webforms and server controls.
If you like to use server controls which do a lot of work for you, you will NOT like MVC because you will need to do a lot of hand coding in MVC. If you like the GridView, expect to write one yourself or use someone else's.
MVC is not for everyone, specially if you're not into unit testing the GUI part. If you're comfortable with web forms, stay with it. Web Forms 4.0 will fix some of the current shortcomings like the ID's which are automatically assigned by ASP.NET. You will have control of these in the next version.
Unless the developers you are working with are familiar with MVC pattern I wouldn't. At a minimum I'd talk with them first before making such a big change.
I'm trying to make that same decision about ASP.NET MVC, Juan Manuel. I'm now waiting for the right bite-sized project to come along with which I can experiment. If the experiment goes well--my gut says it will--then I'm going to architect my new large projects around the framework.
With ASP.NET MVC you lose the viewstate/postback model of ASP.NET Web Forms. Without that abstraction, you work much more closely with the HTML and the HTTP POST and GET commands. I believe the UI programming is somewhat in the direction of classic ASP.
With that inconvenience, comes a greater degree of control. I've very often found myself fighting the psuedo-session garbage of ASP.NET and the prospect of regaining complete control of the output HTML seems very refreshing.
It's perhaps either the best--or the worst--of both worlds.
5 Reasons You Should Take a Closer Look at ASP.NET MVC
I dont´t know ASP.NET MVC, but I am very familiar with MVC pattern. I don´t see another way to build professional applications without MVC. And it has to be MVC model 2, like Spring or Struts. By the way, how you people were building web applications without MVC? When you have a situation that some kind of validation is necessary on every request, as validating if user is authenticated, what is your solution? Some kind of include(validate.aspx) in every page?
Have you never heard of N-Tier development?
Ajax, RAD (webforms with ajax are anti-RAD very often), COMPLETE CONTROL (without developing whole bunch of code and cycles). webforms are good only to bind some grid and such and not for anything else, and one more really important thing - performance. when u get stuck into the web forms hell u will switch on MVC sooner or later.
I wouldn't recommend just making the switch on an existing project. Perhaps start a small "demo" project that the team can use to experiment with the technology and (if necessary) learn what they need to and demonstrate to management that it is worthwhile to make the switch. In the end, even the dev team might realize they aren't ready or it's not worth it.
Whatever you do, be sure to document it. Perhaps if you use a demo project, write a postmortem for future reference.
I dont´t know ASP.NET MVC, but I am very familiar with MVC pattern. I don´t see another way to build professional applications without MVC. And it has to be MVC model 2, like Spring or Struts. By the way, how you people were building web applications without MVC? When you have a situation that some kind of validation is necessary on every request, as validating if user is authenticated, what is your solution? Some kind of include(validate.aspx) in every page?
No, you shouldn't. Feel free to try it out on a new project, but a lot of people familiar with ASP.NET webforms aren't loving it yet, due to having to muck around with raw HTML + lots of different concepts + pretty slim pickings on documentation/tutorials.
Is the fact that ASP.net MVC is only in 'Preview 5' be a cause for concern when looking into it?
I know that StackOverflow was created using it, but is there a chance that Microsoft could implement significant changes to the framework before it is officially out of beta/alpha/preview release?
If you are dead set on using an MVC framework, then I would rather set out to use Castle project's one...
When that's said I personally think WebControls have a lot of advantages, like for instance being able to create event driven applications which have a stateful client and so on. Most of the arguments against WebControls are constructed because of lack of understanding the WebControl model etc. And not because they actually are truly bad...
MVC is not a Silver Bullet, especially not Microsoft MVC...
I have seen some implementation of MVC framework where for the sake of testability, someone rendered the whole HTML in code. In this case the view is also a testable code. But I said, my friend, putting HTML in code is a maintenance nightmare and he said well I like everything compiled and tested. I didn't argue, but later found that he did put this HTML into resource files and the craziness continued...
Little did he realized that the whole idea of separating View also solved the maintenance part. It outweighs the testability in some applications. We do not need to test the HTML design if we are using WYSWYG tool. WebForms are good for that reason.
I have often seen people abusing postback and viewstate and blaming it on the ASP .NET model.
Remember the best webpages are still the .HTMLs and that's where is the Power of ASP .NET MVC.

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