Related
As a novice to this realm, I am planning on building an mvc application. I had originally started a web forms application but decided the scalability and testability will benefit more with an mvc application. I chose to switch with the added benefit of being easier to add more features later on (instead of having code baked into web forms pages).
Now a little about my application, it is an application to stimulate an RPG class builder and moveset. In all simplicity, users can register for a class, and depending on other skills they can register for, they can see a custom move set based on these categories. The way I am envisioning it is I will be able to go back and add more classes and skills later in the database and have users register for this new content immediately once it has been added to the project.
Everything lives in normalized tables, so many joint tables do exist. For each new skill or class I add will mean a handful of tables will be added to the database. This speaks to the way the data will be stored, everything and all information about classes, user data, skills, etc will be stored in the database.
I have designed all the initial database tables I will need to have at the start, and functionality I need (a home page, view skills page, view move sets page, etc.). I am stuck at the next step; where do I go? Should I make my controllers first? Models? Views? Design my page layouts? I am asking for advice from people who have taken a similar organic approach to an mvc project. I am facing analysis paralysis on what to start on, knowing I have a lot of work ahead of me.
Thank you for taking your time to answer.
I've taken everyone's advise and am putting together a website to learn MVC: http://learnaspnetmvc.azurewebsites.net
The most important advice I can give you: just start. A big project can seem overwhelming, especially when you're looking at it like a big project. Instead, break it into small achievable tasks. Find something you can do right now, the ever-so-smallest subset of functionality, and do it. Then do the next one. And the next.
That said, I'll tell you my personal process. When I start on a new application or piece of an application, I first like to create my models. That way I can play with the interactions between them, flesh out the relationships, and think about the needs of my application in a somewhat low-pressure, easily disposable way. I also use code-first, whereas you've gone an created your database tables already. Some people prefer to do it that way. Personally, I find starting with my classes and letting those translate into an underlying data store much more organic. In a sense, it relegates the database to almost a non-existent layer. I don't have to think about what datatype things need to be, what should be indexed and what shouldn't, how querying will work, what kind of stored procedures I need, etc. Those questions have their time and place -- the nascent development stage is not that time and place. You want to give your brain a place to play with ideas, and classes are a cheap and low-friction medium. If an idea doesn't work out, throw the class away and create a new one.
Once I have my models, I like to hit my controllers next. This lets me start to see my models in action. I can play around with the actual flow of my application and see how my classes actually work. I can then make changes to my models where necessary, add additional functionality, etc. I can also start playing around with view models, and figuring out what data should or should not be passed to the view, how it will need to be displayed (will I need a drop down list for that? etc.), and such. This, then, naturally leads me into my views. Again, I'm testing my thinking. With each new layer, I'm hardening the previous by getting a better and better look at how it's working.
Each stage of this process is very liquid. Once I start working on my controllers, I will make changes to my models. Once I hit the views, the controllers will need to be adjusted and perhaps the models as well. You have to give yourself the freedom to screw up. Inevitably, you'll forget something, or design something in a bone-headed way, that you'll only see once you get deeper in. Again, that's the beauty of code-first. Up to this point, I don't even have a database, so any change I make is no big deal. I could completely destroy everything I have and go in a totally different way and I don't have to worry about altering tables, migrating data, etc.
Now, by this point my models are pretty static, and that's when I do my database creation and initial migration. Although, even now, really, only because it's required before I can actually fire this up in a browser to see my views in action. You can always do a migration later, but once you're working with something concrete, the friction starts to increase.
I'll tend to do some tweaking to my controllers and obviously my views, now that I'm seeing them live. Once I'm happy with everything, then I start looking at optimization and refactoring -- How can I make the code more effective? More readable? More efficient? I'll use a tool like Glimpse to look at my queries, render time, etc., and then make decisions about things like stored procedures and such.
Then, it's just a lot of rinse and repeat. Notice that it's all very piecemeal. I'm not building an application; I'm building a class, and then another class, and then some HTML, etc. You focus on just that next piece, that small chunk you need to move on to the next thing, and it's much less overwhelming. So, just as I began, I'll close the same: just start. Writers have a saying that the hardest thing is the first sentence. It's not because the first sentence is really that difficult; it's because once you get that, then you write the second sentence, and the third, and before you know it, you've got pages of writing. The hardest part is in the starting. Everything flows from there.
The other answers here have great advice and important nuggets of information, but I think they do you a disservice at this stage. I'm the first to advocate best practice, proper layering of your applications, etc. But, ultimately, a complete app that follows none of this is more valuable than an incomplete app that incorporates it all. Thankfully, we're working with a malleable medium -- digital text -- and not stone. You can always change things, improve things later. You can go back and separate your app out into the proper layers, create the repositories and services and other abstractions, add in the inversion of control and dependency injection, etc. Those of us who have been doing this awhile do that stuff from the start, but that's because we've been doing this awhile. We know how to do that stuff -- a lot of times we already have classes and libraries we drop in for that stuff. For someone just starting off, or for an app in its earliest nascent stage, it can be crippling, though. Instead of just developing your app, you end up spending days or weeks pouring through recommendations, practices, libraries, etc. trying to get a handle on it all, and by the end you have nothing really to show for it. Don't worry about doing things right and do something. Then, refactor until it's right.
As a first step in planning a MVC framework application, We should start with a strong Model (typical C# props). This process is going to take most of our time, based on the fact that we need to understand the business first and then the relationships between different workflows and entities. So times business models evolve as time passes. So spend qualitative time on building this layer, but not too much.
Once domain (Business) Models are ready, before we actually start coding for Repository classes, we should define our Repository Contracts which are typically Interfaces. Contracts help all parties(other components) to interact with each other in the exact same way. Then we implement contracts on the Repository component, which is just going to act like PUSH and PULL data from your persistent medium (say database). Remember repository component never going to have any idea on business logic.
Once backend has been established, We can concentrate on my actual business process implementation. We can define one more level of Contract which defines all business operations which are to be done using Model classes. This interface has been implemented by BusinessLogic Component which does the core business activity (specific methods for every business operation). This particular component will use Repository component to delegate business data to persistence medium.
With above step completed, We can easily go and build Controllers. We should be calling business logic component methods in controllers and get work done. Once controllers are done, we can define our views and other UI elements like partial views etc.
Pictorial representation of the flow is as follows -
A simple architecture (from high to low level)
Presentation Layer
Domain Logic Layer
Data Access Layer
Database
Presentation layer is MVC project containing Views, Controllers and optional View-Models.
Domain Logic Layer is Class Library project which Presentation layer will access (via DLL or Service reference). This layer contains business logic and rules for the application.
Data Access Layer may contain two sub-layers-
Repository. User repository is best practice for any long term application.
Entity Framework Model.
This will communicate with database.
Database you already have.
I would suggest reading through a book by Scott Millet, called Professional ASP.NET Design Patterns.
ISBN : 0-470292-78-4
Scott walks through what a good ASP.NET site should look like from an architectural standpoint - i.e. DataAccess layers, Business Logic layers, Presentation Layers, Domain events etc.
By following on from industry standards, you will gain a better knowledge of how to correctly put together an MVC web-site.
Hope this helps.
I would suggest you to make your MVC application around a ASP.NET Web API , since it will help, in case you go for a mobile application later.
Since you are a MVC newbie, you should download some open source projects on MVC shared by seniors in the community. Study two or three projects, and analyze a solution which will the best for you.
A quick googling will get you to some good projects.
e.g.
Making a simple application , Prodinner
After that you should also go through MSDN tutorial on MVC 5 app with SSO , to enable social logins.
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.
Closed 10 years ago.
Our product is a web based course managemant system. We have 10+ clients and in future we may get more clients. (Asp.net,SQL Server)
Currently if one of our customers need extra functionality or customised business logic, we will change the db schema and code to meet the needs.
(we only have one branch code base and one database schema)
To make the change wont affect each others route, we use a client flag, which defined in a web config file, thus those extra fields and biz logic only applied to a particular customer's system.
if(ClientId = 'ABC')
{
//DO ABC Stuff
}
else
{
//Normal Route
}
One of our senior colleagues said, in this way, small company like us can save resources on supporting multiple resources.
But what I feel is, this strategy makes our code and database even harder to maintain.
Anyone there crossed similar situation? How do you handle that?
Update:If this is not a right question for SO, can someone move this question to a proper stackexchange site?
Update2:
you are right. The code is becoming smelly now, and I quite sure will be a nightmare sooner or later. Our company is doing the product and to save the effort, later products for other customers are based on the previous one. I know the ideal way is seperate the #e-j-brennan dev teams into 2 parts. One team works on core product and made it highly customisable, and team two works on customising for a particular client. However if since our company is so small, it is really a dilemma situation. :(
I think you need to decide if you sell custom software, that you tailor for each client, or 'off-the-shelf' software that is one-size-fits-all (and maybe customizable thru functionality you provide).
When you only have a handful of clients like you do now, you can get away with what you are doing, but I can almost guarantee that if you continue down this road, and your client base increases and the amount of client-specific customization's increases as well, you will have a nightmare on hand; I've been thru this many times for multiple clients, and it always ends the same way. It all is manageable until it is not, and then it is a royal pain-in-the-neck that could make your life very difficult indeed.
If you decide you are a custom company, and want to have multiple versions of the software and database, that is fine, just make sure you charge the full cost for it - i.e. factor in that you may need to maintain multiple levels of source code and databases and factor in that upgrades are going to take many multiples of effort to rollout as you will need to test each client's code base.
If you decide you want to be an 'off-the-shelf' type of product, then your best bet is provide the ability for each client to customize their experience, without the need for code changes - i.e. built in the customization capability thru config screens and tables that control how things work - but everyone will still use the same underlying code and database. Much more work upfront, but saves you boatloads of time down the road.
I have also been in your position, and I agree it is a difficult one. In my case, I was building custom single-product sites for clients. While each site followed a similar layout and workflow, there had to be enough flexibility for each to have a wholly custom design, custom rules around shipping and coupons, and different merchant gateways and configurations.
After some years, we did end up with something maintainable. First, we created libraries to house all of our common code and put those libraries into a TFS project simply called Common. Then, we created a new TFS project for each site (not client, as many clients had multiple products/sites) and branched the applicable projects into them from Common. Next, we created a VS Template project that contained a skeleton of the site, including "design-less" views, controllers, and their action methods (remember, each site had the same basic flow). Also, each site ran on its own database, which was cloned from an otherwise unused and mostly empty Template DB.
With each site running on its own branch and DB, modifications could be made to the original flow and design that was installed by the template (which would never need to be merged back in) without affecting any other site. For customizing business methods, like shipping calculations, we could create a subclass of the common class and override where needed. Part of what enabled this was converting all our code to use Dependency Injection. Specifically, each Controller had injected Services, and each Service had injected Repositories. Merchant Processing was also coded to an interface and injected. Also worth mentioning is that this allowed us to hard-code all of the upsell logic for each site (you bought product X, so we recommend Y), which was much easier to create and maintain compared to defining complex configuration rules in our old upsell rule engine. I don't know if you have anything like that...
Sometimes we would want to make a change to the Common code itself, which was usually prompted by a specific need for a specific site. In that case, we'd make the change on that branch, merge it to Common, and then merge it to the other sites at our convenience (great for "breaking" changes or changes that also required a change to the DB). Similarly for DB changes, we would update the Template DB and then write a little script to update the other site DBs with the same schema changes ( still had to be smart and careful about it).
An added benefit was that we also created Mock repositories that would be used/injected in a "Design" build configuration, which enabled the designers to jump around the application and work on screens without literally submitting themselves to the workflow. It also allowed them to start working on a site before there was anything done on the back-end, which was very important for those anxious clients who need to "see something".
10+ clients is definitely not a small number with what you're talking about. Three was pain enough for me. We had over 30 sites running at one time, maintained by three developers and two designers.
Finally, I know it's outside the scope of your question and a bit presumptuous, but getting "final" client sign-off on design before the designers actually went about implementing it (and before devs did their thing) also saved us a lot of costly rework. I know no design is final, but increasing efficiency on the implementation end gave the clients less time to change their minds about the design they approved.
I hope that at least gives you some approaches to think about.
People working with systems that have to change or be customized, have developed patterns to handle such concerns.
You should definitely start by reading a good book on Inversion of Control. In short, you can build your systems by defining building blocks (contracts, expressed as interfaces) and provide multiple implementations. There are multiple benefits of such approach but to mention just two:
- you can handle customizations by providing diffent implementations of the same interfaces
- you can reconfigure your application statically or dynamically but both approaches are far more clean than your "if"
When it comes to the data layer, study the repository pattern. It helps to organize the data access in a way that you can switch between different providers. It fits great wiht ioc.
And just a technical tip - nhibernate supports dynamic properties. You just provide additional columns in the mapping and nh is able to support it from the same code base. This way you can target different databases with slightly different db schemas.
I've seen some teams that start breaking into multiple projects from the beginning and others build behemoth single projects. The large project teams say that one massive project is easier to maintain than multiple smaller projects.
In general, how many files is too many?
The answer as George suggested it depends...but you may have large project with many areas which are new feature with asp.net mvc 2.0 . The time when you do want to break it another project is when you are trying to reuse that in another project. Since you do not want something coupled that it needs quite a few changes to work.
So, you need to analyze and understand the reusability of your projects.Ideally you would not want to have one big project with everything...you can divide into libraries..helpers..Models..etc..But again depends on how and what are you implementing..and sometimes a one large project also works.
There is probably no right or wrong answer here, but from experience, some teams know that certain components logically belong in a separate project, therefor they break it down initially.
Some teams might find that because a project is unmaintainable in it's current form, decide to break it down logically into more manageable parts.
As developers, we should always be breaking down problems into more manageable and consumable bits of work. The concept applies to solutions/projects that grow to a size that is just not favorable.
Short and simple answer.
If it becomes to big and messy, break it down.
We don't worry so much about 'files in project', rather we subdivide by 'projects contain logically related function'. Our base libraries are divided by functional area (UI, data access, etc), then the app components by function - reporting, contract maintenance/info, various odd & sundry table maintenance things, deal maintenance/info, rights maintenance/info, etc. (some of the terminology is domain-specific)
Given our translated-from-client/server app is fairly large, we decided that logically related separation would provide a simpler maintenance scheme.
If all your projects are in one solution, there's not really much of a difference (until you get beyond 10 or so projects). If you only plan on having one app, keep it in a single project but separate by folders if you feel that is easier.
We typically separate our project by tiers ... i.e. a web tier project, model/business logic tier, and data access or OR/M tier. It makes it easier for us to manage and conceptually think about the various apps. It also helps prevent us from mixing together concerns (i.e. you probably wouldn't want your model accessing the System.Mvc namespace, but if everything is in one project it's easier for a developer to slip such 'features' in).
I'm in the middle of creating a fairly large flex application, and over time, it's started to edge toward unmaintainability.
I'm using 3 external library projects which are still small enough to remain maintainable and reusable, but the main project seems to be impossible to keep organized.
Part of the problem seems to be that I have about 30 objects inheriting from a single abstract superclass type object. All of child objects have both a logic component and a ui component which are tightly integrated to each other. The superclass object has about 60 shared methods and properties, most of which can be overridden in any of the child classes, a few of which should be overridden in all child classes.
To add to the complexity, these have to communicate between themselves, and this is usually via the container object they reside in. Additionally, the main project has to create value objects out of these so they can be sent to a FlourineFX backend for storage, and additional authentication/authorization logic.
I've created much larger projects in languages from old MS BASIC (pre VB), Ada, VB (3 to .Net 1), C++, and C# without this problem. (well, old VB tended toward this problem because of the same tight integration between UI and logic) So, is there any thing I'm missing, or is there any best practices that I can implement? (even if that means rewriting entire swaths of code)
And yes, this may be an extension to this conversation.
Do you use any framework implementations in this project? A framework would help modularise a lot of this complexity and hopefully remove a lot of the dependencies you seem to have between the application logic and views.
I'm a massive advocate of the RobotLegs framework which implements the mvcs pattern and offers dependency injection for use throughout your project. There are others out there such as pureMvc, Cairngorm, Mate. Have a look around and see which best suits your project.
It sounds to me like you really need to do a big refactor which is a risky process in such a large project. It could be well worth it if you're struggling to maintain it. If you are going to refactor definitely refactor into a framework. It's probably the area that will give you most bang for your buck (pound for the brits ;) )
James Hay's conversation starter is a good one, but for HUGE applications I would take time to test and consider memory management for some of the suggestions in that answer/conversation. RobotLegs is great and all, but I would worry about 'over-singletonization' and potential memory management issues that it would create (though I have to admit that I've never used and avoided robotLegs because of it's use of singletons).
If you were thinking IoC and dependency injection (like that which robotLegs provides), I'd suggest a look at swiz -- I really like the new 'instance-direction' swiz has taken. My only issue with it (in the current beta) is they have some cleanup issues, though these issues are easy enough to remedy (look through their source and any time you completely remove a component from the stage you'll have to play the profiling game and make sure everything is getting cleaned up --- we had to create temp functions to remove the changewatchers and destroy 'display list bean instances' until they get that stuff fixed).
The project I lead had many of the potential issues you must be worried about. Our ERP app has thousands of modules and the thing is running on client machines for hours/days at a time, constantly loading and unloading modules. Garbage collection and memory management were and is THE issues.
As for using mate, the annoying carhorn, or pureMVC, we created our own framework two years ago. It borrowed ideas from cairngorm, but overall my suggestion is to use whatever you can quickly learn, understand and teach while thinking about garbage collection. Our internal Model and View classes now use swiz (for newly developed modules) and this has made maintainability and code readability super smooth.
I hope my blabbing has helped at least a bit.
Best of luck.
It seems like you just need a clean separation of UI and domain components. Look into the component guidelines and the Presentation Patterns discussed by Martin Fowler, especially the Presentation Model.
To bring these pieces together, you might want to use an IoC container like Spring ActionScript. This is a non-intrusive framework that allows you to keep layers separated.
Don't let a framework get in your way. I've seen massive misuse of frameworks like PureMVC and Cairngorm mainly because apply them in an all-or-nothing fashion.
Does data binding fit in a 3 layered architecture? Is dropping a grid-view on a web form and binding it to a LinkDataSource or SQLDataSource considered bad? The way I see it, that's the Presentation Layer talking to the Data Access Layer. I once heard a "professional developer" say never ever do this, so what's the alternative if you shouldn't?
The way you are doing is ok if it is a small project, but if you want your app. to have flexibility to support Windows/ Web in future then you must use Layers.
Please follow this link http://www.dotnetspider.com/resources/1566-n-Tier-Architecture-Asp.aspx
You should have a middle tier between Presentation and Data Access layers, the middle tier is pulled out from the presentation tier and, as its own layer, it controls an application’s functionality by performing detailed processing.
The main task of Business layer is business validation and business workflow.
When you build your business logic components into an SDK, you are effectively disconnecting it from your Web application, and any input validation that it performs. Therefore, your business logic components are the last line of defense to make sure that only valid values make it into your database.
Databinding is, of course, necessary to effectively dispay data.
Tooling is great and can boost productivity. It is equally important to understand what the tooling is generating, even at a basic level, in order to be able to effectively utilize the generated code.
The reaction you describe seems a bit extreme. If a wizard can generate some code that works for ya, then use it. If you don't understand the generated code then that is the next priority; learn about what it is doing and why. In the meantime, you have a page that people can put eyes on regardless of how it got there.
I am a bit pragmatic when it comes to tools. You do what you have to do. But, if after [insert appropriate internship length] you are still using code gen and cannot customize or fix it then you (as in the royal you, not the you you) are being lazy or stupid or both. ;-)
OT:(almost) Never say never unless you want to lessen the impact of what you are trying to communicate.
my 2 pesos.
When you're doing a small project or a prototype, go with the LINQDataSource or SQLDataSource. However, the downsides of those data sources are serious enough for you to think hard if they are appropriate. If your doing a multi-layered or multi-tear architecture, they simply don't fit. But even if your architecture isn't that strict, you should ask yourself how big this application is going to be and how likely it is going to be that you will make changes to the system in the future. How much time it is going to take you when you want to make a change to the database?
I've seen projects were the developers used those data sources, because those were the constructs that were used in those nice ASP.NET video's. However, when the projects grown from prototypes to big production applications (yes, I’ve seen it happen, the prototype seemed good enough), the lack of compile time support (your queries are defined in markup!) made it very hard to do any change to the system.
When you need to make a change to the system, that will be the time that you’ll see that the cost of the change is a magnitude bigger than the time you saved by flattering your architecture.