Here's the situation. We're adding a new application to our suite of webapps based on WebForms and so I felt this would be the perfect time to introduce MVC.
I did all the research about intermingling the two and got the project all set up using an Area that uses MVC routes while the rest of the (visual studio) project runs with web forms the way it's been running.
Master pages were converted to Razor layouts, not too bad because there was only one master page that was shared between every application.
The problem I've run into now is reusing user controls. We have dozens of custom user controls, many of them fairly complex, that are reused throughout all of our applications. Most of them (especially ones that would be difficult to port) do a fair amount with ViewState and postbacks.
If it were just a matter of rewriting these in MVC, the one time cost would be less than ideal but not terrible. But since the existing apps need to be maintained and updated as well, it seems like maintaining 2 versions of the same behaviour using entirely different paradigms would be a huge drain on productivity.
My gut says there isn't really a good solution and we may have to abandon the idea of going to MVC for this project and stick with webforms, but I wanted to see if the SO community has any insight on what to do in this scenario.
If you have the budget to rewrite those server side controls using the MVC paradigm that would be the best way to go. If not, you could still embed them into existing classic WebForms pages and which would communicate with the new MVC application using standard HTTP/HTML techniques: form posts, sending ids through query string parameters, iframes, cookies, HTML 5 storages, etc... One thing's for sure though: try to avoid putting those server side controls in your MVC views. You will end up with some hybrid application that is neither proper ASP.NET MVC nor a proper WebForms which would be a disaster.
Personally I had to do this same migration multiple times and I didn't bother mixing classic WebForms with MVC in the same application using Areas or some other techniques. At the end of the day it might turn into a nightmare trying to make those two exist together. It's always one of the two: I have the budget and I rewrite from scratch properly or I don't have the budget and I do the new stuff properly using ASP.NET MVC and try to interact with the existing application.
I find it easier to simply start a separate MVC application which depending on the interaction I am looking for would use different methods for integrating functionality from the existing WebForms application.
I am not quite familiar with the complexity and details of your scenario so it is difficult to provide an objective answer but the possibility of continuing to write new code based on the existing WebForms server side controls and not doing any MVC at all for this project might also be a good solution. Writing a new application on ASP.NET MVC just for the sake of it might not always be the best choice.
Related
Question : Downside of using Web forms and MVC in same sitecore instance.
Current Situation : We have a Sitecore 7.2 instance developed using MVC and Glass Mapper. We want to reuse existing component which is already developed in Web Forms using the same sitecore version that we are currently using. What we have done so far: To achieve this we did a small POC and were able to achieve the same. We referred below link at Git to achieve this POC We found few blogs where people have done this but always say that it may not work all the time (and not highlighted which scenarios they fail). What are the drawbacks or possible difficulties that we could face doing this ?.It will be helpful if you can highlight as For example :Workflow does not work or personalization does not work etc. Thanks
I am currently running a Sitecore 7.2 instance with both WebForms and MVC (we actually went the other way- our old code is Webform and with a recent redeisgn we moved to MVC) and its doable, but kind of messy.
The biggest issues we've run into have been when we want to display webform and mvc content on the same page, or have the two code bases communicate in any way. Attempting to have renderings calling both webform and mvc code on the same page was disaster. Likewise trying to have webform-only pages communicate with mvc-only pages (eg. building out submenues, getting field values, etc).
In a way, what ended up happening with us was we had essentially two sites - the webforms and mvc versions - and the two never really merged well together. Our project plan was to move off of Webforms to full MVC, so we accepted this as a reality. I'm not sure how well a permanent mvc-webform crossover solution would work, to be honest.
We had some good luck using the following resources: https://www.packtpub.com/books/content/mixing-aspnet-webforms-and-aspnet-mvc
http://www.sitecore.net/Learn/Blogs/Technical-Blogs/John-West-Sitecore-Blog/Posts/2012/06/Using-Web-Forms-and-MVC-in-a-Single-Solution-with-the-Sitecore-ASPNET-CMS.aspx
It's been messy for us, lots of time keeping pages and code apart, and we are planning on cutting out webforms completely in the near future and going full-mvc. But running both is very doable.
Considering the most popular MVC/MVVM client-side patterns (like Knockout.js, Angular.js, Ember.js, and others), I have one great doubt:
Also considering the modeling redundance in both sides, what is the advantages and disvantages to use those client-side patterns with MVC server-side patterns?
I struggled with how to answer this question... hopefully this helps, even if it is in a round-about way.
While some of the pros/cons have already been stated, I think the best rundown is in this answer.
For me, the biggest advantage to using client-side logic is the rich UI aspect.
But the key part of your question seems to be "model redundancy" (I'd call it duplicated logic, or at least having potential for duplicated logic). In my opinion, that is a problem which may exist independently of the pros/cons in the previous link.
So first of all, I think that the decision of whether or not to use a client-side framework should be made based on the well-documented pros and cons. Once that decision is made, the associated problems can be solved.
Lets assume you are using some sort of server-side framework/platform, as well as a client-side framework to provide a little bit of UI interactivity. Now there is a problem with where to put the model logic: on the client, server, or both.
One way to solve the problem is to define your model logic in only the client or the server. Then you have no code duplication, but it affects some of the higher-level pros/cons.
For example, if your model logic is 100% server-side, you lose some of the interactive part of the UI. Or, you are constantly throwing the model to/from the server, which will have a few cons.
If your model logic is 100% client-side, you could suffer performance problems, depending on the size of your view / model. This is one of the reasons Twitter is moving to a server-side processing model.
Then there is "both"... having model logic exist in both the client and the server. I think this is the best solution, as long as no logic is duplicated.
For example, on a shopping cart page, you may recalculate the cost of an order based on the price of a product, and a user-editable quantity box. I think this logic should only exist on the client. Other model properties that do not change once loaded are probably fine hosted on the server.
There's a lot of gray area here... I struggle with putting all the eggs in one basket. For example, choosing a client-side framework, creating a lot of client-side logic, and then [hypothetically] running into problems with performance, browser support, or something like that. Now you may want to tweak a page or two for performance (like move it server-side, a la Twitter). But I think being smart about how you structure your code will help mitigate that issue. If your code is maintainable and clean, moving logic from client to server won't be difficult.
The advantage is that the client side patterns are applicable at the client where the server has no direct reach. If you're building a rich, interactive HTML UI then use client side MVVM. Server side MVC may still be relevant in that case for delivering appropriate content to the client. For example, the ASP.NET WebAPI is a framework for creating HTTP APIs which has a similar controller architecture to the ASP.NET MVC framework. The API implemented with this framework may be called by client side code resulting in MVC on the server side and MVVM on the client side. Normally, when using MVC server side and MVVM client side, the responsibilities of the respective sides are very different and thus there is no redundancy.
The fact you an incorporate a MVVM model into an already implemented MVC framework is also a great thing, we recently added knockout to some new project pages to fit with in an already outdated MVC framework (old pages, not the framework itself).
I think MVVM is fantastic as the above answer states it provides an exceptional user experience with extremely fast response times, you can hide your validation calls in the backround with out slowing them down and its intuitive.
The pain however is that it is VERY hard to unit test and you can get some extremely LARGE javascript files, also the extra coding we've had to do as our legacy systems still run on IE6 is ridiculous.
But MVVM and MVC don't have to be used exclusively on there own, we use both. But having 3 levels of validation is something that still bugs me.
advantages
This can rock.
disvantages
You can screw it.
Seriously. Making use of transporting part of the frontend logic into the browser can boost your application development why you keep more strict data-processing encapsulated on server-side.
This is basically layering. Two layers, the one above talks with the one below and vice-versa:
[client] <--> [server]
You normally exchange value objects in a lightweight serialization format like Json between the two.
This can fairly well map what users expect in a useful structure while domain objects on server-side could not be that detailed.
However, the real power will be if the server-side is not in written in javascript at some certain point because I think you can not create well domain objects there. Consider Scala (or something similar expressive) then if you run into that issue.
Ten months later after this question, I have used the both patterns inside the same application.
The only problem was the need to map the models twice.
MVC (ASP.NET MVC 4 Web API)
The most important resource was the routes.
Models were created to database interactions and as arguments for
controllers' actions.
Controllers were created to manipulate the API
requisitions and to render the views.
Views were not modeled with
server-side models, but all the resources of Partial Views and
Sections.
MVVM (Knockout.js)
Models were created with the same properties as the server-side models.
Views were binded with models' properties, and decreased a lot of the views' size.
View-models were created with the values provided from API methods.
Overall, the MVC combination with MVVM were very useful, but it needed a big expertise and knowledge. Patience is required too, because you need to think about the responsibilites of each application layer.
I'm working in a Banking Online Platform written in WebForms and I'm wondering if the same could or should be written in MVC.
I've read a lot on MVC but i didn't tried yet but i must ask a question for the experts.
Every transaction has a 3 Stage Process where the users input the data, review the data and gets a 3rd step where get's the confirmation. I currently have 40+ processes like this. The way i do it? Single ASPX with MultiView.
How can i do the same in MVC? Would i have 40+ x 3 Views (120+ aspx) ?
Thank U all.
The same can be achieved in MVC by using partial views.
MVC has full control over the rendered HTML and JavaScript frameworks is much easier to implement. It is also a lot more easier to write unit tests.
It is also 'lighter' in the sense that it does not have any View State events (which is the thing that makes Web Forms big when working with big data)
I just started a new GWT project for a client and I'm interested in hearing people's experience with various GWT MVC architectures. On a recent project, I used both GXT MVC, as well as a custom messaging solution (based on Appcelerator's MQ). GXT MVC worked OK, but it seemed like overkill for GWT and was hard to make work with browser history. I've heard of PureMVC and GWTiger, but never used them. Our custom MQ solution worked pretty well, but made it difficult to test components with JUnit.
In addition, I've heard that Google Wave (a GWT application) is written using a Model-View-Presenter pattern. A sample MVP application was recently published, but looking at the code, it doesn't seem that intuitive.
If you were building a new GWT application, which architecture would you use? What are the pros and cons of your choice?
Thanks,
Matt
It's worth noting that google has finally written out a tutorial for designing using the mvp architecture. It clarifies a lot of the elements from the google i/o talk listed above. Take a looK: https://developers.google.com/web-toolkit/articles/mvp-architecture
I am glad this question has been asked, because GWT desperatley needs a rails-like way of structuring an application. A simple approach based on best practices that will work for 90 % of all use-cases and enables super easy testability.
In the past years I have been using my own implementation of MVP with a very passive view that enslaves itself to whatever the Presenter tells him to do.
My solution consisted of the following:
an interface per widget defining the methods to control the visual appearance
an implementing class that can be a Composite or use an external widget library
a central Presenter for a screen that hosts N views that are made up of M widgets
a central model per screen that holds the data associated with the current visual appearance
generic listener classes like "SourcesAddEvents[CustomerDTO]" (the editor does not like the real symbols for java generics here, so I used thoe brackets), because otherwise you will have lots of the same interfaces who just differ by the type
The Views get a reference to the presenter as their constructor parameter, so they can initialize their events with the presenter. The presenter will handles those events and notify other widgets/views and or call gwt-rpc that on success puts its result into the model. The model has a typical "Property[List[String]] names = ...." property change listener mechanism that is registered with the presenter so that the update of a model by an gwt-rpc request goes to all views/widgets that are interested.
With this appraoch I have gotten very easy testability with EasyMock for my AsynInterfaces. I also got the ability to easily exchange the implementation of a view/widget, because all I had to rewrite was the code that notified the presenter of some event - regardless of the underlying widget (Button, Links, etc).
Problems with my approach:
My current implementation makes it hard to synchronize data-values between the central models of different screens. Say you have a screen that displays a set of categories and another screen that lets you add/edit those items. Currently it is very hard to propagate those change events across the boundaries of the screens, because the values are cached in those models and it is hard to find our whether some things are dirty (would have been easy in a traditional web1.0-html-dumb-terminal kind of scenario with serverside declarative caching).
The constructor parameters of the views enable super-easy testing, but without a solid Dependency-Injection framework, one will have some UGLY factory/setup code inside "onModuleLoad()". At the time I started this, I was not aware of Google GIN, so when I refactor my app, I will use that to get rid of this boilerplate. An interesting example here is the "HigherLower" game inside the GIN-Trunk.
I did not get History right the first time, so it is hard to navigate from one part of my app to another. My approach is not aware of History, which is a serious downturn.
My Solutions to those problems:
Use GIN to remove the setup boilerplate that is hard to maintain
While moving from Gwt-Ext to GXT, use its MVC framework as an EventBus to attach/detach modular screens, to avoid the caching/synchronization issues
Think of some kind of "Place"-Abstraction like Ray Ryan described in his talk at I/O 09, which bridges the Event-Gap between GXT-MVC and GWTs-Hitory approach
Use MVP for widgets to isolate data access
Summary:
I dont think one can use a single "MVP" approach for an entire app. One definetly needs history for app-navigation, a eventbus like GXT-MVC to attach/detach screens, and MVP to enable easy testing of data access for widgets.
I therefore propose a layered approach that combines these three elements, since I believe that the "one-event-mvp-system"-solution wont work. Navigation/Screen-Attaching/Data-Access are three separate concerns and I will refactor my app (move to GXT) in the following months to utilize all three event-frameworks for each concerns separately (best tool for the job). All three elements need not be aware of each other. I do know that my solution only applies for GXT-projects.
When writing big GWT apps, I feel like I have to reinvent something like Spring-MVC on the client, which really sucks, because it takes a lot of time and brain-power to spit out something elegant as Spring MVC. GWT needs an app framework much more than those tiny little JS-optimizations that the compiler-guys work so hard on.
Here is a recent Google IO presentation on architecting your GWT application.
Enjoy.
-JP
If you're interested in using the MVP architecture, you might want to take a look at GWTP: http://code.google.com/p/gwt-platform/ . It's an open source MVP framework I'm working on, that supports many nice features of GWT, including code splitting and history management, with a simple annotation-based API. It is quite recent, but is already being used in a number of projects.
You should have a look at GWT Portlets. We developed the GWT Portlets Framework while working on a large HR Portal application and it is now free and open source. From the GWT Portlets website (hosted on Google code):
The programming model is somewhat similar to writing JSR168 portlets for a portal server (Liferay, JBoss Portal etc.). The "portal" is your application built using the GWT Portlets framework as a library. Application functionality is developed as loosely coupled Portlets each with an optional server side DataProvider.
Every Portlet knows how to externalize its state into a serializable PortletFactory subclass (momento / DTO / factory pattern) making important functionality possible:
CRUD operations are handled by a single GWT RPC for all Portlets
The layout of Portlets on a "page" can be represented as a tree of WidgetFactory's (an interface implemented by PortletFactory)
Trees of WidgetFactory's can be serialized and marshalled to/from XML on the server, to store GUI layouts (or "pages") in XML page files
Other important features of the framework are listed below:
Pages can be edited in the browser at runtime (by developers and/or users) using the framework layout editor
Portlets are positioned absolutely so can use scrolling regions
Portlets are configurable, indicate when they are busy loading for automatic "loading spinner" display and can be maximized
Themed widgets including a styled dialog box, a CSS styled button replacement, small toolbuttons and a HTML template driven menu
GWT Portlets is implemented in Java code and does not wrap any external Javascript libraries. It does not impose any server side framework (e.g. Spring or J2EE) but is designed to work well in conjunction with such frameworks.
Seems like every project I'm on uses a Model View Controller architecture, and that's how I roll my own projects. Is there an alternative? How else would one create an application that has persistent storage and a user interface?
MVC has been around for a while. It's a time tested and proven pattern. Many frameworks leverage the MVC Pattern. Martin Fowler has deconstructed the MVC into: Supervising Presenter and Passive View.
Architect Christopher Alexander said it best:
Each pattern describes a problem which
occurs over and over again in our
environment and then describes the
core of the solution to that problem,
in such a way that you can use this
solution a million times over, without
ever doing it the same way twice.
I'm not sure why you would want to move from MVC. Is there a problem you are encountering that MVC does not eloquently solve? To give you a better answer we need to know more about your problem domain.
Things to take into account when considering patterns/architecture: If you are building something with a Myspace type architecture you'll need a robust architecture (MVC). If you are creating a simple crud interface via the web - almost anything will do.
For .Net Web forms (I am assuming web, since you didn't say thick or web client) which is not MVC, it was a nightmare maintaining them. Web Forms applications that lived more that a couple years tended to become big balls of mud. Even then developers discovered ways to use MVC with web forms.
Ironically, the lack of MVC architecture in ASP.NET web forms was one of the driving complaints that lead to the development of ASP.Net MVC framework.
From experience if you don't use some MVCesk approach, your solutions become hard to maintain and bloated. These applications will die a slow painful death.
If your solutions are small one-off projects, the by all means throw something together. Heck there are tools that will generate everything from the screens to the data access layer. Whatever works to get the job done.
Classic CRUD apps built using tools like VB6 and Delphi have user interfaces, persistent storage and don't use MVC. Most of them used data aware controls linked directly to database fields
Couple of links comparing various MV* patterns which might be useful:WPF patterns : MVC, MVP or MVVM or…? & MVC, MVP and MVVM
Look into MVP model view presenter.
User interface is View and an application will always have a model and the bridge between the two is Controller. The whole MVC is nothing special as this is how the things will be always.
At the most you can get rid of Controller and have your view talk to your model but you loose the flexibility.
I've developed an alternative to ASP.NET MVC. You get the same loose coupling and separation of concerns but the difference is in how you go about building your projects.
I have a couple of videos on my blog, source code for the framework, a sample project and a few VS.NET add-ins (New Project item, New Builder and New View).
Builder for ASP.NET
Some key differentiating Features are
1. Templates are just html - no code mixed with templates
2. Templates are thus reusable across views and Web site designers can design templates in their design tool of choice
3. Strongly typed code (no ViewData and stuff) so you get intillisense, compile time checking, F12 navigation etc.
4. You build pages as compositions of views rather than an inside-out approach
5. View can be treated as "real" classes.
6. Everything is complied so no run-time compilation
Quite a few other differentiating factors as well.
In theory :
MVC is a proved technology and yada-yada-yada, and it is ideal for websites.
But in a real case:
A serious project that use MVC required a framework, hence you are following a framework with all their limiting and restrictions. So, at this point, the specific implementation of MVC is rule and not a simple "guideline".
Also MVC fail miserably for websites when it is about to connect to the model other than simple POST/GET, it fail with xml asynchronism and it fail with ajax. (*)
(*) exist some patch but a design must be clear and functional and if you need to "patch it" then it is neither clear nor functional.
Personally i think that the main problem with MVC is that it put so much effort in the Controller, where most project use not more that 5 lines for the controller part.
ps: Most "well done" MVC projects are 3-tier project.
ps2: MVC excluding some framework, is just a buzzterm, IS NOT A SERIOUS TERMINOLOGY and it is reflexed in the group of "interpretation of mvc".