I am developing the administration part of a site. It mostly consist of manipulating list of data such as:
Products
Suppliers
Tax profiles
...
I find the task of creating a controller that handle the CRUD operations of each model a little too repeating and prone to mistake from one controller to another.
I would still need to adapt some of these controller for additional operation, but not all.
Does someone know a proven approach for reducing the implication of controller for the usual CRUD operations?
One suggestion would be to look at tweaking the T4 template that is used to generate the scaffold methods. Check out Rob Conery's MVC Starter Site to see what he's done (look in /Web/CodeTemplates in the source for the general idea).
There are also some other MVC libraries out there such as FubuMVC that aim to cut down on code repetition, but it's not based on the actual ASP.NET MVC framework (and it's not really my thing).
Related
[Pre]
I have to say that I'm dummy newbie who is trying to get together important puzzles with such crucial details as DDD, TDD, MVVM, and EFCore. I have an about 10 years of windows form develop experience in complete wrong manner, and after I'm joined to Plurasight I'm understood that I'm just lost my last 10 years, and this is really sad :).
[Problem description]
I have an App that i want to re-write from scratch by using latest and greatest technics that've learned for the last 6 month on Pluralsight, but the problem is that these new knowledge’s is stopping me, because simply I'm afraid that I'll do it wrong again...(that is stupid I know, but it is what it is).
So back to my questions, I have a big problem domain, and pretty well documented business logic, which i have to turn in to the code. I'm understand that my start point is design data layer, for these purposes I want to use Entity framework core (I saw Julie Lerman's course on Pluralsight and I think's she is amazing and inspires me to use EFCore as ORM for my app). But at the same time leakage of experience produces more questions than what I’ve learned with Pluralsight, and I will try to write them all(please don’t judge me too hard)
It is looks like that I will need 2 or even more data model projects in my solution, and here is why I have multiple document set types, each of the type contain more than one reference books used to generate unique file names and data sheets. But it looks weird to me have 3 Data model projects such as MyApp.PackType1.DataModel, MyApp.PackType2.DataModel, and each of them will be preinstalled with the EFCore, and each of them will generates its own database based on Data Context defined by EF. Isn’t it very redundant or this is correct way?
I don’t understand how to join these multiple Data Models projects, including Shared Kernel into the one nice model
I don’t understand what is the best way to design my data classes? Should they be just POCO’s or I can design them as nice looking classes with the private var’s and public properties? What are the best practices in here?
Also I don’t understand what is the best practice to use a MVVM pattern on top of that, and is it applicable at all to use MVVM in this case?
Should I keep my Tests in separate projects like MyApp.PackType1.DataModel.Tests, or keep them in same project?
Best regards,
Maks!
P.S.
Apologize for unclear definitions and questions, English isn't my native language.
It's very complicated to answer your question because you have asked for a lot of details, but I going to provide a brief answer and I hope it will be helpful.
You can have only one model for your entities (DDD) and create sub model from this model in your end level projects (Web API or UI)
Read point #1
You have to create an Entity Layer project that represents your database and then you can create DTO's for specific scenarios
From my point of view, use Angular but you can use another UI framework such as React or VueJs, but I prefer to use Angular to build UI interfaces and consume .NET Core Web API from client
Create unit tests and integration tests for you Web API projects and as additional feature you can use Db in memory provider for tests
May be this guide is useful: https://www.codeproject.com/Articles/1160586/Entity-Framework-Core-for-Enterprise
Regards
Hm, multiple DbContexts (models) usually come about when you have distinct databases you are using. General rule is one Context = one Database. Exceptions can occur when there are a lot of tables that can be grouped functionally, but there are downsides to that approach.
A DbContext is a repository pattern but for individual tables. Using a Unit of Work pattern and layering with a custom repository provider would allow you to make it "appear" as a single database, hiding the complexity from the front-end.
Your entity descriptions are usually created as straight POCO. You can get creative with different DTOs
In a nutshell, an MVVM pattern goes like this:
Request from UI to a controller
Controller possibly issues multiple calls to Data Layer to gather data
Assemble data in a single ViewModel (everything the page needs)
Return to UI
The beauty of the approach is single roundtrip (request/response) to the UI
Separate Project in my opinion. There are techniques to spoof the database connection using EF so you are not using "live" data.
That CodeProject article will come in handy.
I know the question is about solving the problem probably by different approach but let me specify in details what I want to ask and how much I understand about it.
We have two mvc approach used in ATG(or many other framework) pull based and push based.
As I understand it formhandlers and droplet both are playing the part of controller in different need, repositories are our model and jsps are providing views..
And if i am right till this point then what purpose the servlet chain is solving?How it fits into this picture of MVC?
Please If possible explain with the help of flow diagram from request to response (end to end).
Thanks a lot in advance to experts.
Please help.I could not find this kind of explanation anywhere.
The first thing to remember with ATG is that it is an old platform. So when trying to understand the different mechanisms through an MVC lens, remember that nothing was designed with MVC in mind-the platform predates widespread knowledge and acceptance of the MVC pattern in web development.
Droplets are a generalized mechanism for invoking Java code from a JSP (and previously, JHTML) template. The closest analogue in J2EE-land would be tag libraries. So you can use them to accomplish many different tasks. You can also use them as a poor man's MVC controller. This is done by coding a custom droplet class dedicated to handling the business logic of your page, and setting relevant page state as request parameters. Then you invoke the droplet as the first step in your JSP page. This is not very different from J2EE model 2 with the odd quirk that first your compiled JSP begins executing, then invokes your "controller" code and then resumes with processing the "view."
Form handlers, as the name indicates, are designed for processing form submissions. These are executed by a link in the servlet pipeline (DAFDropletEventServlet), before the page which was posted to begins rendering. Typical usage with form handlers is that they will send a redirect after executing, and cancel rendering of the page, which will abort any further processing by the servlet pipeline. Form handlers are the closest thing to a "controller" ATG provides. But they are awful for handling GET requests and result in some very unfortunate URLs when used for this purpose.
Why did they create two different mechanisms? Why have they not subsequently introduced an updated MVC model as part of the platform? These questions I cannot answer.
ATG, at the page rendering level, is not MVC. Don't look at it as MVC. ATG, at its core, is an extension of the basic Servlets API.
Forms and form-processing, with the successUrl and errorUrl is kind-of MVC. Droplets certainly are not.
It is perfectly acceptable in an ATG application to be fetching data as the page is rendering (i.e. Droplets)
I'm working on a database application that manages industry-specific inputs and then runs that information through somewhat complicated calculations, lookups, etc. to return a series of other values and a go/no-go conclusion.
I've decided to use Entity Framework (code first for provider independence) and WPF (MVVM pattern). I'm using the POCO entities as my data model and the view model is handling the usuals like basic data / business rule validation.
It seems EF + WPF/MVVM are great at displaying and validating input and getting it into the database for querying for your typical business application like a products, customers, orders setup. But it's not at all clear where to plug in a "calculations layer". Between the view models and the data models (my POCOs), things are already feeling a bit bloated, and now I'm facing adding another layer very much like the other two.
Perhaps the best way to approach this is to make the calculations layer a sort of meta-view model and push as much of the validations, change notification, etc. into them and run with lighter actual view models.
Anyone run into a situation like this?
Edit
Turns out what I really needed was to thin the view models and beef up the entities. So I lightened the view models, moved property change notification and basic validation to entities to allow for direct binding, and made calculation classes directly consume entities as well as adding some basic routines to entities. Thanks for the links on thought ADM articles #Peter Porfy.
For moving validation closer to entities, used Fluent Validation (excellent suggestion #Gloopy!). To make it easier to implement property changed notification on entities, adapted this technique. And to avoid having to create endless property wrappers in view model (to set HasChanges property) I used Josh Smith's PropertyObserver.
MVVM stands for Model-View-ViewModel, where the Model layer contains everything what models your actual domain problem.
So it depends on what you mean 'calculation layer'.
Put it where it belongs.
If the actual operation belongs to a domain entity, then you should put that logic into the entity. Don't make anemic domain models:
Article from Martin Fowler about ADM.
DDD works perfectly with EF code-first.
If something doesn't belong to any entity then probably you should expose that as a service. Then use that from your viewmodels through an interface.
A dependency injection container could make your life easier here, but you can live without it.
You aren't plugging another layer because it's the model layer. Your viewmodels should stay as thin as possible, just modelling your view's state and forwarding actual business operations to the entity/service classes.
I'd probably create an interface/object to handle calculations (or several if they can be split up logically) and pass that object in wherever you would want to use it. You might benefit from using a dependency injection framework maybe this post can help with that so you wouldn't have to explicitly instantiate your objects where you need them.
Also this post mentions FluentValidation.NET which may not apply completely but there are likely some good patterns to learn from/use there as well.
I have been using jqGrid as my grid view to my data for some time now. It works well and it was easy to implement into my solution. However, due to some refactoring going on within the project right now, I have been looking into it again.
The project itself is built around ASP.NET MVC 2 (.NET 4.0). We need some extra functionality such as:
Being able to add columns.
Inline editing of columns.
Sorting
Filter
Paging
Searching
jqGrid does all of this (although, not all of this functionality is implemented yet - some of it is new based on new needs). But, given that I am using ASP.NET MVC, I was wondering if it would make more sense to switch to the Html.Grid helper. It looks just as easy to implement for the things I know it can do (Sorting/Filtering/Paging), but I do not know if it can even do the other tasks (in a fairly straightforward manner) - anything I have found seems somewhat "hackish."
Can anybody enlighten me on A.) the capabilities of Html.Grid to jqGrid and B.) if there is any reason I'd want to take Html.Grid.
I use jqGrid successfully with ASP.NET MVC 2 (.NET 4.0) and have all the features which you describe in your question. Moreover all pages having jqGrid looks like very simple.
I don't use Html.Grid or any MVC controls. I include just pure HTML fragment <table id="list"></table><div id="pager"></div> on the page. Additionally I include the JavaScript which initialize the "list" table and the "pager" div as the jqGrid. So the implementation is independent from MVC concept. The most important part of the jqGrid integrations is the actions which get back pure JSON output and which implement GET/PUT/POST/DELETE operations with the jqGrid. You can read more about the approach here (see also many links with code examples included in the answer).
To be exactly I prefer to use WCF as a part on my ASP.NET MVC solution and the WCF methods provide the data needed for jqGrid (see here more details), but you can implement all as pure ASP.NET MVC actions.
If you use Unit testes for you ASP.NET MVC site you can successfully write tests for WFC methods or controller actions used by jqGrid. In the way you will test the most parts of jqGrid implementation.
After looking at both approach, I decided the jqGrid was a far easier (and simpler) approach for what I was attempting to do.
I need to re-write a businesss InfoPath / SharePoint application that has a fair bit of logic associated the operations a user performs - such as enable / disable controls; show / hide controls (complex tab controls); retrieve different data nad display differenty - as determined by user activity.
In trying to decide whether to use ASP.Net Web forms or ASP.Net MVC. As such I have been hunting around for a good realworld ASP.Net MVC sample business application (with Source code).
Does anyone know of anything that can demonstrate to me how to achieve the 'richness' of user interactions and responses in ASP.Net MVC that one can achieve using Web Forms?
I am know the Dinner Nerd application; and have checked out the offerings on CodePlex. So far most of the sample applications I have found do not have much of the complexity we have become used to dealing with in Web forms; and that I need to try and achieve. I posiibly have have to rethink the presentation & flow of the application in response to user actions in an MVC application (as compared to how one migh structure the flow in InfoPath / Winforms and Web forms). This might shift me more to what the existing sample applications might be indicating to me -'change the focus of the Views to be of presentational bias'. As such one would end up with many views each only permitting a reduced set of use interactions.
Thanks for any comments in advance.
Grant
There is exactly the same question asked here (ok, it is not about business apps) - Real World ASP.NET MVC Applications with Source Code?
just keep in mind that asp.net-mvc makes it really easy to write unit tests, which is the most important thing when coding applications.
If you have complex interaction scenarios you might be interested in performance too, asp-net.mvc performance is a way better...
Asp.net-mvc 2 (I haven't looked at 3 yet) makes the validation really easy and you can choose at which level you want it.