I am trying to make a website in ASP.NET MVC, but I am not really sure how I should organize things. N-Tier applications seem to work nice, but since I am a beginner programmer it is pretty hard to understand. I just want to create a small web application where people can login and create pages. In these pages they can add others things. The database won’t be bigger than 10 tables I think. Even though it is a small application, I would like to use some best practices that N-Tier applications use.
Is this a good approach? Or is it very wrong? :
Project.Models
Models that represent the entities in my database.
Project.DAL
Interfaces and implementations for my repositories and unit of work. Also my NHibernate mappings.
Project.BLL
Interfaces and implementations for my services.
Project.UI.Web.MVC
My controllers, viewmodels and views. The controllers get data from services and pass data (viewmodels) to views so I think it’s part of the UI.
There are no hard and fast rules about how to organise your project.
That looks pretty logical to me and seems to follow a lot of hte examples that i have seen across the internet.
All that matters is that its logical to you and your team in my opinion.
Take a look at this link as well, might be a lot of useful information for you there:
Best practices for MVC architecture
That sounds like a neat layering.
Define clearly on what goes in DAL, BLL and Web.MVC. Because people can have difference in opinion in what goes into business logic and ui logic, I suggest to have a weekly review of what has went into each layers - to start with.
One suggestion is to call Project.UI.Web instead of Project.UI.Web.MVC.
Related
I recently worked at HP doing several ASP.NET MVC3 projects as I came from a software background I was relatively new to the inner workings of MVC3 as well as the best practices.
During this time I somewhat adapted the coding style of fellow co-workers and ways of designing my pages that I still stick with to this day. With all of this in mind my main question is what would anyone recommend for learning material; books/videos/tutorials. I can learn from any of those resources and I would love to know that I am coding properly.
I have several projects under my belt and many large scale business solutions that I have coded using Razor and ASP.NET but there are times where I feel that what I am doing is either very hacky or just an inefficient way of coding things. The larger the project is the more difficult it becomes to add new features because of this.
I think this is my lack of experience in coding but at the same time I would like to overcome this and I feel that with the mass experience I do have with MVC3 I could adapt to a easier style or design pattern that would help me not only optimize my code but become a much better web developer. If anyone has any suggestions on books or training sites or anything please let me know as I would love to get better.
Thanks in advance to anyone that has been in my shoes and is willing or capable of recommending anything!
I was dealing with the same issue and found it useful to make a mind map. While it's impossible to give you a full understanding, I can try point you in the right direction with some basic ideas.
download/view (http://www.xmind.net/share/highroad/mvc3-design-pattern/)
Are you familiar with design patterns? Well they exists with MVC applications too :)
If you want to talk the talk and understand what people including myself are talking about, you would need to know the typical design patterns that come with building what they call enterprise level applications. These design patterns are the only real way to begin to understand the concepts.
These patterns structure complex business logic in ways that have become the tried and tested solutions (design patterns) to the design challenges the developer's face.
In the diagram notice there are 3 main layers:
Presentation Layer
Business Logic Layer
Data Access Layer
Some of the highly used design patterns when dealing with Model View Controller in ASP.NET include:
Business Logic Layer Design Patterns:
Active Record. Models relate exactly to the database like in lightweight frameworks e.g. Ruby on Rails). When creating new MVC3 application with ASP.NET and scaffolding views and controllers, this is how it sets it up. Is perfect for less complex applications. So why not just use Ruby on Rails? I would
Domain Logic Layer. Uses MVC with the controller containing very little code and create lots of extra models that can do complex logic, the MVC is only for presentation. Often with this style of layer, a lightweight layer called a Service Layer can be used to call all the functions in the Domain Layer from the controllers i.e. the controller calls the method in the Service Layer class which calls the domain layer. This design pattern seems to be very popular with people who enjoy object oriented programming. See link below to my (quite basic) project designed using Domain layer.
Transaction Script - Use the controller to do a lot of the logic work per action, the problem is a lot of actions need to do the same things so there will be code repetition
For the Data Access Layer:
Something like entity framework models combined with a repository which can perform any SQL queries you need.
Not going into all the patterns for this layer but they include: Data Mapper
With simple apps, there is no real data access layer, it only becomes necessary if you use the Domain Layer in the business layer (which usually is the case)
Depending on what structure your application takes, your Models will mean very different things. In general they will not be models linked to the database (the default when creating a new app makes them like this). Instead they will be ViewModels which are only responsible for holding data that each of the views will need.
I have created a ssample app which you can see here.
https://github.com/testbrian/enterpriseframeworksB
I don't know if this is an example of an enterprise solution, but I have learned a lot from the techniques found in RaccoonBlog. I like how the Layout.cshtml and other razor files use RenderAction to modularize the views.
The project is an example of MVC3 using RavenDb, but it's also one of the best real world applications I've seen since it's actually used in production.
Hope this helps.
I would like to know the best practice for a designing a simple CRUD application with some screens updating various tables (like admin pages to maintain static data for an application). the simplest way would be to drag a data grid/gridview, bind it to a dataset and use a data adapter for CRUD operations. but if this application needs to be scalable, lets say to add any extra UI/business logic in future, then is there any design pattern that can help with this? should I be using an object data source control and bind it to business objects instead? or are there any better ways of doing it? should I build a complete layered application or will that be overengineering for this requirement? any examples for UI design would also be helpful. thanks.
If you are looking for a really quick and easy approach, you can look at using Dynamic Data
http://www.asp.net/dynamicdata
on top of a Linq2SQL or EF4 backend - hardly any code needed at all.
+1 Oded. No offence RKP but you might be confusing "simple" with with "effective" or "value-for-money". I also think you might want to be more clear about exactly what it is you're after: example UI designs is quite a different issue from the logical architecture. Anyway - good on you for asking.
If this is a "tactical" solution: not expected to have a long life-span, or is a quick-and-dirty dev tool then how you build it might not be such a big issue. (also beware that short-term tactical apps can end-ed being long-term strategic ones - were working on an app now that the business see as a "temporrary" tool: they see it only being used for the next 5-10 years (!)).
If it's a tool the "business users" will use, then it's quite likely they'll expect changes overtime: depending on what the app is for a simple pass-through CRUD app might only cut the mustard for a short while.
So I guess this is where your admirable desire to look at best practice comes in.
Are you familiar with OO design? A lot of the principles behind good OO design also apply at the architectural level (SOLID, Common Reuse, Common Closure, Loose Coupling, Stable Dependancies and Stable Abstraction Principles).
lets say to add any extra UI/business
logic in future
So - this is where you need to consider up-front how you will seperate concerns and allow for growth: architecture doesn't mean you have to do a big upfront design, it just means you need to have an idea of how you'll grow the application as requirements grow..
To finish:
Have a good look at the different system quality attributes and work out which ones are particularly relevant to the system. prioritise them.
I get a lot of mileage out of Dependency Inversion (The D in SOLID) - abstract out things like data access early on.
For me the other really key "best practice" is to pay attention to SRP (the S in SOLID),
http://www.asp.net/mvc is my bet. It's easy to start with and get going... You won't be dissapointed. :) StackOverflow itself is built on top of it.
Need to design ASP.net pages which are mostly datadriven pages (read/write to sql tables)
through a interface.
This is mostly for maintence of job queues (to job on hold / delete from queue => which in turn is updating or deleting view.
What would be best Pattern to do with such maintence pages.
Thanks
If you're looking for a quick fix, you could try Dynamic Data.
While I do agree that a good solution for administrivia style sites such a the one you are describing is easily handled by Dynamic Data as #Robert Harvey has suggested this is not quite a direct answer to your question.
I think you really can't go wrong with using the ASP.NET MVC framework with some DDD concepts tossed in. This of course may be over architecting a small problem however let me suggest why I like it so much. With ASP.NET MVC you don't have any heavy obstacles to worry about ...just nice pure HTML. Form there following a good domain driven design you can quickly get some layers running. Plug in LINQ to SQL and you are off and running. With the MVC framework you can also easily make just about everything test driven which will help to keep the site maintainable over time.
I have written a whole series on DotNetSlackers regarding architectural concerns in ASP.NET MVC from a simple app all the way back to a complex distributed SOA style application. I have one more article (covering the SOA portion) to go to complete the series but there are many other articles in this mini-series that you could get started with.
Take a look at the "Three Tiers to MVC" section on this TOC of the bigger series
If this really is an admin site that you are creating though...do take a look at the Dynamic Data option. Very powerful!
We are currently designing a business application that has two primary requirements for it's UI:
1) run on the Desktop (WPF) for enterprise users to provide a rich user interface, interoperate with other applications, access the filesystem, work offline, work with special local hardware, etc.
2) run on ASP.NET/Ajax to provide several components of this application to customers (internet). Unfortunately Silverlight is not (yet) an option.
Even though we don't have to make the full application available on the web, some of these components are fairly complex and we would like to share as much UI code as possible with the WPF implementation.
What options do we have to reach this goal? Is there a pattern that works well with both technologies?
Update:
Thanks for the answers even though they don't include the one I was looking for! :)
I don't think UI generators are a good option. Like Eduardo pointed out you will probably end up with problems in both worlds. I will check out Sculpture though.
I've been thinking along these lines for a while now, and I've yet to come up with a great answer. That being said, here are some of my thoughts:
If you used some variation of the various MVP/MVC/MVVM UI methodologies and you were very disciplined in this approach (i.e. not mixing presentation stuff with behavior stuff), you'd probably be farther down the road.
You might consider investigating the various DSL toolkits that have cropped up, the idea being to create a simple "language" to describe your UI at a high level and generate a representation of that UI in WPF/ASPX.
Also, I ran across this recently. I have no idea how good it is. I'm planning to take a closer look when I get the chance.
Good luck!
The unfortunate truth is that Asp.net/ajax (the web in general for that matter) and WPF (and heck, let's throw WinForms in there for good measure) have very different User Interface models and what works well for one is not necessarily going to work well for another. That's not to say that you can't share logic between applications written for either technology, but, I'll make a stretch here, your UI logic is not going to be in that category.
I've been using a variation of MVVM for WPF and ASP.Net MVC most recently and I'd say they are very good fits for the technology at hand. However, while they are very similar, they have their differences and I'm not sure you could write an abstraction layer (in any decent amount of time) that could take advantage of the great features in both technologies.
Ultimately, I'd say that your best bet is to follow some SOA patterns and extract as much of your business and data access logic into common libraries as possible. Then, write separate user interfaces in WPF and Asp.net to take advantage of those common libraries. This is the approach that my company is taking at the moment, and it's working like a charm.
It may seem daunting to write your UI logic twice (once for asp.net and once for wpf), but I think it's worth it so that your code can fit the patterns and practices that best fit those technologies.
As an aside, even though Silverlight is not an option, have you considered XBAP?
If a former job we did something similar. As Daniel Pratt says, we describe our interfaces in XML and then a render will create the form, report or whatever we decided to create.
We have to provide a Javascript function to do some UI validations in the HTML render, and a call to a java function in the Swing render.
Beware that you may end with imperfect apps in both worlds.
I am just starting a new ASP.NET project and using the MVP pattern. I did consider the MS MVC but it is not released yet and would be a big learning curve for some people on the team, so I opted for MVP now and possibly future projects MVC.
Anyway, it seems I will have a single Controller/Presenter class for every webform I have it the project. This is a lot of extra classes, essentially doubling the number of files in the web project. Is this how other people structure MVP or what are the alternatives?
This seems to be a common misconception -> "More files/classes == more complex"
The reason we chose to follow a UI separation pattern is to help separate concerns, make code easier and cheaper to change and maintain and (big, important and) we can unit test the complex parts and still keep the UI layer slim.
I'm going with the beta ASP MVC. The reason being, that while it is still only a beta (PDC very soon, that may have an impact on release and we've had 5 preview releases) it has a better framework to support this style than I could write in a reasonable time frame.
You could of course go with another framework, like castle monorail.
I think a lot of it depends but in most cases that is really the way it ends up going.
I personally use a n-tier architecture with data, business, presentation code. (Who knows what actual format I follow). I do get a lot more files than if I did everything in the aspx, but the code is much easier to manage.
To your question - I have seen many different takes on MVP and seen nothing that reduces the number of files, and I can't think of a way to reduce the number of files.
In my experience, I have reused view interfaces and even code behinds where the view structure is identical, but presenting different data. And you could also think of reusing the controllers where applicable.
I think it is worthwhile to note that having more files will be a natural consequence of moving to a more agile and test-drive development and developers will find it more and more natural as they go. (Just like some of us find it very natural having lots of methods inside a single file...)