MVC 3/Design Patterns issue - asp.net-mvc-3

I made a settings page for my website. On this page the user is presented with a bunch of site wide settings they can manipulate. I made it so when the user selects a setting the page will automatically run an ajax request to send the setting to the database. My question is in how I do this.
At first I just did calls to the repository. One call to get the data back, put it into a ViewModel then give that ViewModel to the View and the ajax controller just sent the settings back to the database. This way seemed like the best at first especially for unit testing purposes since I could just pass in a fake repository if needed. Then for the user to get a setting they just called the repository and pass in the setting name they want.
Then I had a bright idea. I made a singleton class called SiteWideSettings and each possible setting on the site was a property of the site. When SiteSettings is called for the first time all of the settings are loaded. When Set is called on any of the properties it will call the repository function to send the setting. Now with my Settings view I'm just passing in SiteWideViewOptions.Current and on the ajax call I'm updating the property that was changed. This is working for me however it's not very unit testable since I can't really pass in a repository to a singleton's constructor since its constructor is private. What I currently have is working fine but I just don't feel like it's the best solution and unit testing isn't really possible here.
I'm thinking of one of the following but not sure which is the best.
Add a Repository property to the SiteWideSettings class
Add a function to the SiteWideSettings class to pass in a repository
Not use a singleton for this at all and just go back to what I was doing before I had this idea
Any comment on this would be greatly appreciated.
Note: I know. I know I'm doing unit testing wrong in this case because I didn't write my test first so please don't scold me for that.. I have already scolded myself and with my next task I won't do it again I promise :)

"Then I had a bright idea. I made a singleton class called
SiteWideSettings and..."
This sounds like a bad idea. Let your database be ground-truth for what the settings are, not some in-memory cache that you now need to keep up to date. Let your ORM do caching if you need it for performance otherwise you are just adding problems especially if you now try to run your site on more than one server.
If you want to simplify the controller so it has less 'set-up' and 'tear-down' code in it, use an IOC (e.g. Autofac) and inject any dependencies you need (e.g. a DataContext or a Repository) on a per-http-request basis.
Your action methods are now easier to test since you can simply instantiate your controller (injecting the dependencies manually using its constructor) and then call your method.

Related

AsyncCrudAppService Breaks Swagger When Providing TCreateInput and TUpdateInput

I recently downloaded a Single Page Web Application (Angular) from https://aspnetboilerplate.com/Templates using 3.x target version.
I just simply added a few entities and then started to follow the steps on this page https://aspnetboilerplate.com/Pages/Documents/Application-Services
Things do work well for me to Get, List, Update, and Delete entities when my app service class is just inheriting AsyncCrudAppService<Entities.PhoneBook, PhoneBookDto, long, GetAllPhoneBooksInput>, however when it is inheriting AsyncCrudAppService<Entities.PhoneBook, PhoneBookDto, long, GetAllPhoneBooksInput, CreatePhoneBookInput, and UpdatePhoneBookInput> the swagger definition will no longer load.
GitHub Repo: https://github.com/woodman231/MyPhoneBooks
(which currently does not work and will not load Swagger page).
I can get the swagger page to load by removing CreatePhoneBookInput and UpdatePhoneBookInput from
https://github.com/woodman231/MyPhoneBooks/blob/main/aspnet-core/src/MyPhoneBooks.Application/SimpleCrudAppServices/ISimplePhoneBookCrudAppService.cs#L9
and
https://github.com/woodman231/MyPhoneBooks/blob/main/aspnet-core/src/MyPhoneBooks.Application/SimpleCrudAppServices/SimplePhoneBookCrudAppService.cs#L14
However, again I am still unable to create entities using this default implementation. Any ideas?
I have cloned your repo and run it and I figured out the error, first as I tell you in comments I verified the text log, and it said the next:
System.InvalidOperationException: Can't use schemaId "$CreatePhoneBookInput" for type "$MyPhoneBooks.SimpleCrudAppServices.Dtos.CreatePhoneBookInput". The same schemaId is already used for type "$MyPhoneBooks.PhoneBooks.Dtos.CreatePhoneBookInput"
What happenig is that you have these two classes UpdatePhoneBookInput, CreatePhoneBookInput repeated in SanokeCrudAppServices\Dtos and PhoneBooks\Dtos
You have the classes in both folders with same exact name, and thats the problem, if you change the name in whatever place the swagger definition will load without errors, I have do it like this and everything works fine!
Change the name in one of the places, and all will be working fine
Personally I don't like to use a different Dto for Create and Update for me is easier to user just one Dto for all.
Ok I figured it out. I had also made a DIY AppService and some of the DTO Class Names associated with the DIY App Service clashed with the DTO Class Names associated with the Automated Service. It was acceptable in .NET since they were in different name spaces but once the swagger definition was configured I assume that there was multiple instances of the same DTO Defition. I checked the AbpLogs table but they didn't give me much details as to the specifics of the internal server error while loading the definition. It sure would have been useful to know that.

How to stop grails erasing custom validation errors

In my Grails app, I am using methods in a service to do complicated validation for user submitted data. Unfortunately, Grails is quietly sabotaging me.
I populate the domain instance with the user submitted data
I hand the instance off to the service, which analyzes the properties.
If errors are found I add them using
instance.errors.rejectValue('myValue','errors.customErrorCode','Error')
BEHIND THE SCENES, when the service passes the domain instance back to the controller grails checks for changed properties and calls validate() before returning the instance. (verifiable by seeing the beforeValidate event called on returning a domain instance from a service to a controller where one or more properties has changed)
That behavior clears any custom errors I have added and the instance I get back in the controller is now incorrectly without error.
How can I
A) stop grails from validating between service and controller
OR
B) prevent a validate() call from wiping my custom errors.
EDIT
So far I've found one partial answer,
If you use instance.get(params.id), grails will self validate behind the scenes wiping custom errors.
If you use instance.read(params.id) you can bypass this behavior to an extent.docs
But this solution is limited by domain relationships. Any other solutions welcome.
Seems that it is not custom validation. It can be because of transactional service. Service opens separate transaction for each method and clears entities after method end. You can find this mentioned in docs(read the last paragraph of part ). So errors dessappear not because of validation.
Don't know if your service is transactional. But if it is - you can add #NotTransactional annotation to method were you want not to loose errors. And
errors will be saved.
Hope it helped,
Matvei.
Not sure how your code looks like or what is causing the problem, but in any case I strongly suggest implementing custom validators in the domain class or in a command object within the constrains.
Here are some examples from grails docs:
http://docs.grails.org/2.4.0/ref/Constraints/validator.html

How to organize my code?

I'm still in a learning phase with PHP and Laravel 5 and since I upgraded to L5, I struggle with where my code belongs to. There are so many files and folders which seem to have the same purpose or at least are very similar. There are Commands, Controllers, Events, Services, Requests, etc. I give an example with my workflow and where I would place the code and I hope you guys can comment on that and correct/help me.
Situation
I want to register a new user in my application and send a welcome e-mail when he registered successfully.
Workflow
Controller (UserController): Returns requested view (register).
Request (RegisterRequest): The "RegisterRequest" validates the entered data.
Controller (UserController): Passes the validated data to the "UserRegistrar" (service) in 'App/Services'.
Service (UserRegistrar): Creates a new user and saves it to the database.
Controller (UserController): Fires the "UserWasRegistered" Event.
Event (UserWasRegistered): This Event call the "SendWelcomeEmail" Command.
Command (SendWelcomeEmail): This Command will send/queue the welcome e-mail.
Controller (UserController): Redirects the user to a view with the information that he has been registerd successfully and a message has been send to him.
Logic
Okay, let's discuss some logic:
Controller:
Doesn't hold much code.
Mainly there to return views (with requested data).
Handles workflow and "connects" modules (Services, Requests, Events).
Request: Validates the data for a specified request
Service: A service "does" something. For example it's doing requests to the database.
Event: An Event is a central place to call one or more tasks if it is fired (SendConfirmationMail, SendWelcomeMail).
Command: Mainly there to handle the logic for ONE certain task. For example sending a confirmation mail. Another command will hold the logic for sending the welcome mail. Both commands are called in the Event described before.
Repositories: What is that?!
So this is what I understand. Please help me and feed me with information.
Thanks,
LuMa
Your question is a little vague and will likely attract downvotes as being "too broad". That said, here's my take on this...
The biggest issue I see is that your application structure is very different from the recommended L5 structure - or even the standard MVC structure - that it's no wonder you're getting confused.
Let's talk about your "Logic" section:
controller - you're on the right track here. The controller is the glue between your models and your views. It can do some processing, but most should be offloaded to classes that handle specific tasks.
request - what is this? L5 includes a Request class that includes methods for examining the HTTP request received from the client. Are you talking about subclassing that? Why? If your idea of a "request" class is primarily concerned with examining input, you can either do that in your model (ie. validating stuff before sticking it in the database) or in your controller (see the L5 docs on controller validation)
service - again, what is this? You talk about "doing requests to the database", but L5 provides a class for that (DB). At a higher level, database access should primarily be done through models, which abstract away most of the low level database access. As for other services, what I usually do is create libraries to perform specific processing. For example, my application has a particular third party project management application that it accesses via an API. I have a library for that, with methods such as getProject or createProject.
event - An event is a way of ensuring that some code is called when the event happens, without a whole lot of messing about. It sounds like you have the right idea about events.
command - again, it sounds like you have the basic idea about commands.
repositories - these are way of abstracting the connection between a resource (primarily the database, but it can apply to other resources too) and the code that uses the resource. This gives a way to switch the underlying resource more easily if you (for example) decide to change database servers in the future. They are optional.
You also haven't mentioned anything about models. L5 provides an excellent way to deal with your data in understandable chunks via Eloquent models - this will make your life much easier.
My suggestion is this: start small. Build a simple MVC application with L5 - A model (to save some data), a view (to display the data), and a controller (to put the model & view together by handling the client request). Once you have that, start extending it.
There are tutorials out there that will give you this basic structure for Laravel - most are for Laravel 4, but see if you can follow the basic ideas and build something similar for Laravel 5.

How to prevent controller, service and repository constructor executed by the mvc sitemap provider's menu html helper?

In the _Layout.cshtml, the #Html.MvcSiteMap().Menu("viewname") caused extra 2s in each request. I found that the repository's constructor being executed several times depends on the menu's count so I guess this might be where the extra 2 seconds cames from.
Is there a way to prevent the constructors be executed once the menu rendered?
I suspect the reason for this is because you are using Security Trimming. In order to determine whether each link has access, MVCSiteMapProvider creates and releases an instance of each controller for each action. The only way to avoid this is to disable security trimming.
With security trimming enabled, it is not recommended to have any heavy processing within your constructors, as this will negatively affect performance. You should defer any processing (such as opening database connections) to later on in the request lifecycle by using an Abstract Factory to create the connection and injecting the factory into your constructor instead of the dbcontext/connection object. See this post for an example.
That said, the AuthorizeAttributeAclModule is not as efficient as it could be because when you have controllers with a lot of action methods, the same controller instance could be reused instead of creating one for each action method. You could make a custom AuthorizeAttributeAclModule and use the HttpContext.Items dictionary to request-cache each controller so they are reused instead of re-instatiated. You will need to do some refactoring to do it, though. The controller is created on line 235 and it is released on line 108. You need to make sure that the release isn't called until the after very last node is checked. You can do this by creating an IActionFilter to release them after the action is complete, but it means that action method will need to know about the same request cache (in HttpContext.Items) as the AuthorizeAttributeAclModule. You just need to implement the OnActionExecuted method to clean up the controllers from the request cache.

Using Session Vars in a MVC Domain Model library

I have a IQueryable function. In that function, I need to store and retrieve data to Session; can you guys point me in the right direction.
I've looked at the HttpSessionStatBase where the session is usually taken from HttpContext.Current but this doesnt seem possible to do in the library. Am I missing something?
Thanks in advance.
I would avoid having a dependency on the static HttpContext. My preferred strategy would be to extract the information from the session in the controller and pass it as parameters (or set as properties) on your data access layer/repository. If you feel that you must use the Session directly, then I would provide it to the DAL/repository in the same manner -- as a property or as a parameter. Note, however, that you are increasing the coupling between your DAL/repository and the controller. This will make it much more difficult to re-use in a non-web setting, i.e., you'd have to create a fake session just to interact with the DAL/repository if you ever needed to work with it from a windows service or console app, for example.

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