I have my existing web site developed using ASP.NET.
It's college management system. Now I need to redevelop it on MVC2.
What all changes do I need to do?
I am little bit aware of MVC and have done some exercises also.
Thing I know is I can keep my database intact but there will be massive changes at other places.
WHat will be the better way to minimize the changes?
MVC is a very different concept from event-oriented WebForms. There's good chance you will have to redo the frontend completely.
Try to find out if there is anything resembling data access layer and the business logic layer. If so, you can keep them (at least partially) and reuse their methods.
However, if the current application is not well structured and looks like a giant code blurb (with no layers, parts of the code talking to any other part at will, page methods going directly to the database etc.) it may have to be redone entirely.
If the application is now heavily relies on data-bound controls, you're screwed. You will have to recreate a lot of functionality by hand.
You should be able to refactor the middle tier (if you're using a multi-tier approach) into controller/model while keeping the UI intact. Once you've done that, throw away your UI and write a proper View. Try using LINQ-To-Sql for the backend.
Related
I am not starting an argumentative discussion here and this post is not about career development, but from the commercial point of view:
If a company was using ASP.Net MVC as a main methodology to build their web sites and application.
However, ASP.Net MVC takes more time to show a functional application than ASP.Net Web Forms, for example, building domain models would take some time which obviously can't be represented on a UI at that current stage.
My question is, if a client wants to see a functional demo application (just a proof of concept) so he knows that the company he is dealing with is professional and capable of doing that. Would it be better to do that demo in ASP.Net Web Forms only to show the client, and then work on the real application using ASP.Net MVC? If not, what are the (quick) alternatives?, I mean, if we tell the client to wait till we have a working demo (by ASP.Net MVC) we may lose the client and the whole project opportunity.
WebForms being faster than MVC is a myth:
You are not required to have a domain model, just something that represents your database tables. This is the same in WebForms unless you are using SqlDataSource's.
The code in your !IsPostBack or btnSubmit_OnSubmit is almost identical to the HttpPost controller actions. Except with MVC you don't have to write left to write object.FirstName = txtFirstName.Text when you understand how UpdateModel works.
UI is UI. If you know HTML/CSS creating the UI is just as easy. Almost easier in MVC because you don't have to set control properties any longer and all UI can be done in one place.
Fast MVC comes from understanding how to get the most bang from your buck using EditorFor, DisplayFor templates. You'll need to know and understand how to customize your Object.ascx file. With this technique under your belt you won't have to create forms by hand anymore. 2 projects ago we had a site with 100% autogenerated forms. Change a class, change a form. Done!
Another helpful MVC tool is the DataAnnotations attributes. Validation made easy. Customizing these is really easy too. Just create your own ModelMetaDataProvider and starting expanding the validations your application can handle.
The only part of MVC that is slower is displaying a grid. MVC 3 already has a useful grid tool and MVCContrib has had a grid tool out for a year now. I ended up rolling my own, its very simple actually, loop through properties, write <td />'s. < 200 lines of code. This isn't really a benefit to WebForms either. To use WebForms grid components means giving up a lot of quality using ObjectDataSources and the like.
To summarize fast MVC comes from these different techniques:
Object.ascx
ModelMetadataProviders
UpdateModel
DataAnnotations
If you are more advanced and know ORMS like EntityFramework and how to use Automapper your probably going to be even faster.
You can get a demo up and running very quickly in MVC. I could put one together much quicker than with WebForms, and I am familiar with both.
The reliance on convention in MCV will help a lot, binding is based on the names of objects.
If i was creating a quick demo, i would just create a bunch of ViewModels with static data in them, different button clicks etc will just bind one of these ViewModels to the page.
Turbo Fast!
I build prototypes in excel. No logic, no code. just basically screenshots to show the user that we are communicating the same ideas. Create a worksheet for each "View" or screen you need to show. Client's usually only care how "pretty" an application looks vs does it work right.
This also is a benefit as you can include more non-technical users in the prototyping process, since most are used to excel. I can send you an example and the finished production web application, if seeing is believing. I personally learn best by example.
And to your post where you wrote...
I mean, if we tell the client to wait till we have a working demo (by ASP.Net MVC) we may lose the client and the whole project opportunity.
They need to have their expectations adjusted and managed. A lot of bad development has been done quickly over the years, which makes client's ask questions like "Bob did it in 1 hour'. To that I say, you can either have a lousy project fast, that you have to constantly duct tape or a well thought out and well written project that will only need to be enhanced as Bus Reqs change
I think the answer is obvious: use whichever you think makes you faster. There's no point in using MVC if you are faster in WebForms. Especially since this is for a throw-away demo.
I know this question has been asked before and I read all the answers but they still don't give me the answers I am looking for. I need something concrete. I volunteered to give a presentation on MVC to other developers in our group which forces me to learn it. The big question everyone has is: "What can MVC bring to the table that we can't do in asp.net or MVC can do faster. I have just gone through Nerd Dinner and actually created a complete website that sort of mimics Nerd Dinner. But as great a job that Scott Guthrie did on it, there are big gaps that aren't answered such as, how do I throw a textbox on the listing page with a button and do a simple search. In asp.net, I would throw a textbox, button and grid on the page and bind it to a sproc and away I go. What is the equivalent in MVC. I guess I need a really good tutorial on how to use MVC without using Linq-to-Sql.
I know I am sort of babbling on about this but it is a very serious question that still seems to go unanswered.
On a side note, the View page of MVC brings back nightmares of classic asp with all the in-line code that we got away from way back when with code behind pages. Yes, MVC has Controller and Model classes which are great but I still don't like the classic asp tags in the html.
Help me out here, I really like the concept of MVC and want it to be successful but I need more!
how do I throw a textbox on the listing page with a button and do a simple search. In asp.net, I would throw a textbox, button and grid on the page and bind it to a sproc and away I go
That's exactly the biggest problem behind "classic" ASP.NET aka WebForms.
You shouldn't be thinking in terms of pages, buttons and events.
You should learn the basics of how web works. Then you'd understand that the web speaks in terms of HTTP protocol, its commands GET, POST and others. Presentation is HTML, CSS and the Document Object Model which is where JavaScript comes into play. And there are in fact no pages, an url is just a pointer to a resource which is not necessarily mapped to a physical file (.html or .aspx) on the server.
the View page of MVC brings back nightmares of classic asp with all the in-line code that we got away from way back when with code behind pages.
I also came to MVC after staying with WebForms and I discovered I like the inline code very much. It makes the view structure very clear, which cannot be said about the coupling of static markup (aspx) + manipulating server controls in code-behind. The latter is actually a nightmare - your code is generating the markup output but you don't see where and how.
What can MVC bring to the table that we can't do in asp.net or MVC can do faster
It removes the ugly stateful abstraction which WebForms gave us. You're now back where it started. What you have now is:
Option to separate your presentation part (views) from your application logic. Before there was all mixed together, code-behind talking to the database, calling other services, modifying the markup. It was mess. It resulted in lots of serious applications written but hardly maintainable any more.
Ability to automatically test your application logic. With WebForms and code-behind, how would you invoke a certain scenario? You'd use tools like Selenium to mimic user activities. Now, when your views are just a passive presentation layer, you don't have this problem any more. You test your business logic and model output very easily. Views are there to display the results. If the model got the correct data in a particular scenario, the view will display it correctly. If not then not. Period. No need to test views.
Control over your markup. That is if you care. If you a former Windows developer who doesn't give a damn about HTML documents being valid, being semantically correct and optimized for web engines, then it's of no use to you. I mean, "pages" are sort of displayed, user clicks are processed like in desktop application, what else, right? But if you were interested in all those things, then you'd look at the final markup output and see that it is ugly, with lots of errors, limitations which you simply can't fix. Because it's how controls, buttons, data grids etc. display themselves. An attempt to fix them would require to override markup generation of those controls which is a heavy task. Why don't just drop it and do everything manually?
What MVC takes from the table?
A server-side processing of "control" "events", like in Windows programming. If you're developing a desktop-like application for web medium, like those typical "business" software with dozens and hundreds of controls to drive you crazy, then MVC will drive you crazy, because you will have to wire each single control individually with JavaScript.
But if you're not developing those kinds of applications (which require certain mental abilities to work with), but developing modern usable software for web, then WebForms would drive you crazy. Sooner or later.
I was also learning MVC in the past few days. My experience is that is provides a much less complicated model of the web.
While WebForms promised that it will make web development very close to Windows development with a complicated event model, controls, and all the stuff.
Why? Because at the time Microsoft's developer base was mostly VB and C++ developers who were thinking in terms of forms, controls, and this provided an easy way for them to begin developing for the web.
What MVC provides is more control over the underlying protocol and more control over the HTML you output.
Plus, they give you ASP.NET routing built-in, so your URLs will also look and feel much better.
An example: StackOverflow was built using ASP.NET MVC.
Your example:
how do I throw a textbox on the
listing page with a button and do a
simple search. In asp.net, I would
throw a textbox, button and grid on
the page and bind it to a sproc and
away I go.
You create an Action for it in the current Controller, throw a form on the page with Html.BeginForm which points to that action (remember, with MVC, you can have multiple forms on pages), throw a textbox and a submit button in it.
Then, according to your taste, you can either create a separate view for the search results, or reuse the existing view. The new action can be named the same as the old one, with [HttpPost] on it (or [HttpGet] if you prefer that), so the URL won't confuse the users more. You can then call your SPROC in your action and you are good to go.
(All this accomplishable in a matter of minutes.)
The other thing I like about MVC is that it is basically VERY EASY to create CRUD operations with it. (Like NerdDinner.)
VS generates 80% of the code required for your views, which then you can customise very easily.
I recommend you reading the whole book and not only the NerdDinner free episode, it gives you a very good picture about the technology.
The bulky Behind code is one the biggest issue with Webform. The RAD approach is good to create project faster but the growing bulky behind code is not maintainable , reusable and testable. There are 5 problems which MVC resolves of WebForm.
Problem 1 :- Webform was a View based solution for Action based requirement
Problem 2:- Tight coupling between behind code and view
Problem 3:- HTML is not the only response type in Webform it was not flexible
Problem 4:- Flexible Combination of view and data not possible with webforms
Problem 5:- Behind code was a heavy bulky class which can not be instantiated.
All the above points has been explained in this codeproject article http://www.codeproject.com/Articles/821275/Why-ASP-NET-MVC-ASP-NET-MVC-vs-ASP-NET-webforms
The following article got me started with MVC
ASP.NET web forms aren't going
anywhere. As much as I love ASP.NET
MVC, it is not the end-all-be-all
one-size-fits-all solution to web
development. Both of these approaches
have their rightful place in a web
developer's toolbox and it's important
to recognize their strengths and
weaknesses. In general, the ASP.NET
MVC framework tends to sacrafice
ease-of-use (e.g. viewstate,
validation, etc.) in order give
developers tighter control over the
reins. This can be a great thing, but
only if you take advantage of it.
Otherwise it can just as easily be a
hindrance.
With that in mind, I have developed a
quick metric to determine if ASP.NET
MVC is right for you. The way I see
it, there are three primary reasons a
developer should choose the ASP.NET
MVC framework over ASP.NET web forms.
If none of these reasons are
compelling to you, then you should
stick with ASP.NET web forms:
To Unit Test This, in my opinion, is
the most compelling reason to use
ASP.NET MVC. When it comes to unit
testing, ASP.NET MVC simply blows
ASP.NET web forms out of the water.
It's not even close. Whereas ASP.NET
web forms requires you to jump through
all sorts of hoops to test around the
page event lifecycle, the ASP.NET MVC
framework practically begs to be
tested. There are interfaces
everywhere screaming "mock me!".
There's a reason why the biggest
ASP.NET MVC supporters also tend to be
TDD proponents; it's because ASP.NET
MVC actually allows for TDD.
Personally, I think this is where all
the zeal comes from. Simply put: it's
really, really hard to do TDD with
ASP.NET web forms and really, really
easy to do it in ASP.NET MVC.
To Gain Control and Extensibility As
pointed out in the comments, ASP.NET
MVC gives you more control and
extensibility options than ASP.NET web
forms. You get complete control over
the page request lifecycle and the
ability to substitute out several key
pieces of the framework (e.g. view
engine, routing, etc.), none of which
is possible with ASP.NET web forms.
In addition to this, you also gain
full control over the rendered HTML.
In general, the rendered HTML from
ASP.NET web forms applications is
atrocious. The web controls it
utilizes generate garbage ids and
hidden fields galore that not only
hamper the performance of a site, but
also make CSS styling and Javascript
development a pain. ASP.NET MVC
forces you to be more in tune with
your HTML. There aren't any repeaters
or datagrids that magically generate
markup for you. There aren't any
hidden fields to persist state for
you. It's just you, the HTML, and a
few extension methods (which you don't
even have to use).
To Learn Something New In other words,
"because you feel like it". This was
actually why I started using ASP.NET
MVC. It never hurts to look at how
you're approaching development from
another angle.
I should also point out that learning
ASP.NET MVC is incredibly engaging
process since the ASP.NET MVC
framework team has been so interactive
in the process. I think a large part
of the appeal of ASP.NET MVC is that
the community's input is not only
being taken into consideration, it is
actively being sought after. The
framework has sparked so many
discussions and debates over best
practices that simply following along
introduces you to concepts you might
previously have been unaware of. I
would actually recommend learning the
ASP.NET MVC framework for this reason
alone. The threads on TDD, BDD, ORM,
AJAX, etc. you stumble across during
the learning process are worth it.
So there you have it. Aside from
those three, I can't think of any
other reasons why a developer would
learn ASP.NET MVC. Maybe this is why
the adoption rate isn't nearly as high
as we think it should be. The
incentive for using the framework
essentially boils down to unit
testing, control/extensibility, and
boredom/curiosity. Good reasons, to
be sure, but hardly game breakers for
the vast majority of developers out
there.
Control over the HTML output - is one thing. All those fancy controls SERIOUSLY SUCK from a SEO point of view.
Plus for COMPLEX forms, the ASP.NET state model is hell, too ;)
Anyhow, an example is your search box... it sucks ;)
I would use MVC like this:
Search is a URL:
/search/keyword
or
/search/keyword/pagenr (like /search/programming/5
Good thing is: I can easily have search results spidered by google - some sites I Know get most hits from something like that.
Is it harder to program than asp.net - depends whether you want efficient HTML or not. THe control model from ASP.NET does not lead to lean defined HTML somehow.
Besides that - MVC is a lot more testable. Unit testing a classical HTML site is pretty impossible, the decoupled model of MVC makes that easier.
I don't come from a Microsoft background, so I might be missing something strictly related to ASP.NET but MVC isn't something different than ASP.NET. MVC, or model-view-controller, is an architectural principal in software design that isn't strictly for the web. Graphical user interface applications commonly use this model.
Anyway, your question is dealing with the "why". The search listing page is a good example to start with. With MVC, you can use templates to only modify the visual aspects of the search (the view). You can add buttons and format what the controller gives you without having to make changes to the controller itself. Similarly, with a view you can change the logic of what is "given" to the view without actually changing the view. Finally, you can go from a relational database to an XML database and without having to worry about changing any of the other aspects of your program. The logic is separated cleanly and this pattern fits many use-cases.
I would highly recommend seeing the Wikipedia article on MVC. It may be easier to understand using a graphical user interface (GUI) example instead of a simple web based example.
Ryan
MVC is considered as an alternative to good old asp.net, not the next step. IMHO MVC has a clear advantage if you want to write unit tests for your pages.
But I don't agree that MVC adds anything to classic asp.net in the name of performance, code quality or productivity. You can achieve same performance with asp.net by shutting down viewstate when not necessary or you can be more in control of HTML output by using lightweight server controls. (Repeater instead of DataGrid for example.)
In my application, I have a situation wherein the users will need to have the flexibility to customize the UI to a certain extent. The following are some of the customizations that is being discussed now...
Change Label text associated with the with Use Input controls
Mark a control as Mandatory/Read only/Hidden
Assign a regular expression for the text box
Are there any recommended design patterns for my situation? Seems like I need to store all these in a database and worried about the performance impact if I have to read every element from the database for every page.
Thanks,
Harsha
I would look at some of the open-source CMS or portal systems written in ASP.NET and see how they are doing UI customization (if they are).
Phil Haack has some insight at the following article:
Scripting ASP.NET MVC Views Stored In The Database
http://haacked.com/archive/2009/04/22/scripted-db-views.aspx
Apparently it's not an easy thing to do in ASP.NET. It's easier to do in ASP.NET MVC, because the markup is cleaner and you can control it with jQuery.
The overall concept you are going for is not easy to have system wide, however the specifics you stated are fairly easy.
You'd have to setup some fields in a database for those values and then on the page load set those values on the page load. Pretty trivial from a 'how to'. Which your question shows that you 'get'.
Now unless you are using an Access Database :-), I don't think you have to worry about the performance hit. But if truly concerned, put some caching logic on those values so you only have to hit the database once. Though, be aware this will store the values in memory on the server, so if you are working with a very minimal hardware this could be an issue as well.
I'm currently working on a high-traffic online search site.
They have various changes they want to implement over time, and they've indicated that ultimately they want the site re-done in ASP.NET MVC.
Currently the site is an ASP.NET WebForms project; however true ASP.NET controls are rarely used. Instead there are lots of server-side tags - i.e. <% ... %>. The code in these tags will usually be a call to a static method in a static class or a fragment of C# code that generates HTML.
Many of the static methods generate HTML by appending text to a string-builder and returning it as a string.
I understand the concept of a 'Helper' method, but I don't like the idea of the HTML being rendered by concatenating it to a string variable. I think they'd be better off using 'Partials'.
The thing that concerns me is that it's a pretty complex site, and I'm not sure if a complete rebuild of the site in ASP.NET MVC is a good idea.
In spite of the bad structure, it's not really that hard to add the new features that are being requested. (Perhaps because I've had past experience working with difficult code).
However I think there's a risk that at some time in the future, a requirement will come along that will be very difficult to implement unless we do a complete clean-up of the code-base.
I want to put this question out there and see if anyone's faced a similar issue, and how you dealt with it.
Also what are your thoughts on doing the re-build as a 20%-time side-project? Are there any downsides to doing it this way?
Wow, this is some project.
Personally I think any site written in ASP.Net will need to be totally re-done as far as the UI is concerned. MVC does it a whole lot differently.
Your business logic on the other hand should be ok though me thinks so long as you have seperation of concerns and it's not bound to the UI.
Data access should be ok and probably needs minimal touching. But that again depends on how tightly bound your web site is.
I think the best approach is to spend some time looking at how MVC does business and do a critical analysis of what it would take to convert and then begin converting all the layers above the UI in preperation.
Get your foundation in place and maybe even, if possible, use the MVC framework already. Again, only if you can and only if viable.
Doing this as a side project would work I think because you can take some of your libraries and begin converting them in preperation for the mvc conversion.
But be mindful that once you have converted a project/layer that you (do) implement it else it runs the risk of being forgotten or changes get made to the other layer that then need to be coded into the new etc. You know the traps.
As for the UI, that's going to be the big one especially if you use a lot of asp controls. You maight want to spend a lot of time evaluating the UI and come up with a list of controls that you either need to replace or write. Then you can begin to see a pattern and get some consistency going.
If you have a lot of code in your code behind, you may want to begin moving this to another layer as this will help later on when you create controllers etc. They can then instantiate your new layer and all should be good.
That's all I can think of from the top of my head. I'll edit or comment as I think of things.
Hope this helps.
If I have that project and I was asked to redo it from scratch, I will not use MVC to render the UI, I will use Web API/OData to host all the backend, and will use any good Front End to draw the UI, Angular will be a very good option.
Having it as a side project is good only if the pace of changes and new features in the old project is less than the progrress done in the new project, you don't want to end up with doing duplicate effort and at some point you will have to code freeze the old one.
Also, you have to consider any data migration if you will have to change the data storage option.
I'm in the process of designing a solution for the company I work at (but have just resigned from) which has a very complex application process in it. The process is close to 10 steps (including T&C's and preview) and also has some very tricky UI-level business rules (mostly driven by a legacy tie-in system).
Essentially the validation is driven by what has been selected on previous forms, and not just the one directly prior.
The solution has already been decided as an ASP.NET application but the more I design the solution the more it's looking like it's going to be very difficult to achieve in a stateless environment. It's going to either end up with query string parameters, hidden variables on the page, viewState or session to pass the information around.
Then I had it suggested that I look at Silverlight, to give it a more stateful environment and make it easier to handle the passing of the parameters around.
I've never done anything with Silverlight, other than watch presentations, so I've got no hands-on experience with it, but from everything I've read I think that it does have potential to solve some of the major problems which I can see coming out of trying to do this with standard ASP.NET.
So how do I go about:
Is Silverlight a viable option considering what I mentioned above?
Pitching Silverlight to a company without any Silverlight skills?
How do you deal with the "but it requires a browser plugin" argument?
From what you're saying your problem is about keeping state between multiple pages/forms. Sessions are good for that (not so much the query params or hidden variables as those can be tampered with, just having to think about that possibility when developing your app will slow you down.) I'd recommend that as simplest all round.
However, you can also put several forms on one page and submit them together, but have it look like different pages using javascript. It wouldn't be too hard to do with any decent javascript library, but I recommend jQuery (Microsoft is adopting, over their own, as the standard for ASP.NET)
Same as the silverlight problem if your company doesn't have many skills in javascript, but at least it doesn't require a plugin.
Don't get me wrong, I love silverlight, I love it so much that when it gets market share similar to flash, I'd drop HTML/css/javascript. It just doesn't seem to fit for you though.
I currently work for a company that builds its primary LOB app in Silverlight.
Silverlight may be a good choice for what you are trying to do, but consider:
Using Silverlight won't reduce the complexity of the application.
If you're already comfortable with ASP.Net, you can deal with complex workflow using existing idioms (Session state, the wizard control, or plain old CLR objects of your own that implement a decision tree/state machine model).
If your problem is really an issue of workflow design, you can integrate ASP.Net apps with something like Windows Workflow Foundation. However, "won't reduce the complexity of the application" probably applies to this, as well; in my limited experience, Windows Workflow Foundation hasn't made building workflows simpler, either.
What you gain by having state all wrapped up in local client objects will most likely be smaller than the cost of learning Silverlight and its idiosyncrasies.
That being said, there's nothing wrong with the idea of attacking this kind of problem in Silverlight. It's just not a silver bullet or anything; Silverlight has its own data access headaches, quirky UI code idiosyncrasies, and requires wrapping your head around yet another model for developing applications.
Silverlight has a Page class that enables you to easily support navigation where you can go back to the previous page as you do in your browser. I think Silverlight pages and the navigation framework is very suitable for the kind of application you have described.
Using Silverlight enables you to create a very rich client experience. Doing that is probably also possible in ASP.NET to some extent, but I find all the moving parts in a traditional web application (HTML, CSS, JavaScript etc.) and their interactions much more complex than the Silverlight model. If you don't have experience using Silverlight you could create a simple page navigation prototype without any real logic to get a feel for the experience. If you are satisfied you could then show it to management to demonstrate the power of Silverlight. If they like eye candy you could change the visual theme of your application in an attempt to impress them. This tactic may backfire, though, if management actually prefers battleship grey.