Free Software Development Course. Login details for this Free course will be emailed to you. Email ID. Contact No. The controller acts as a bridge between view and model layers and hence provides the user interface to the application.
The presenter is used to show the output to the user with the interface. The view is more or less connected only with the model. The coupling in MVC is between the Controller and View to handle the business logic and hence to present the result. Only one user interface is used, which is most basic as this is the primary architecture evolved into designing the application.
Since the user interface is used more, there are a large number of interfaces that make the architecture heavy. Business logic and any other logics are present only in the model layer where the data is present. Business logic and UI are separate, and hence testing is done easily on the layers as separate and also as integration testing. Debugging is done with the help of ASP. This approach is called the "Passive View".
The disadvantage is that you can't leverage things like databinding which is really powerful in frameworks like WPF and Silverlight.
In that case your View might have a property called Customer, which then again is databound to the UI widgets. You don't have to think about synchronizing and micro-manage the view, and the Supervising Controller can step in and help when needed, for instance with compled interaction logic. He covered all the flavors of MVP and showed C code to implement them. In some cases the model can also be used to turn a data source into a higher level abstraction as well.
A good example of this is the MVC Storefront project. The distinction made is that in an MVC application traditionally has the view and the controller interact with the model, but not with each other.
Having said that, ASP. To perhaps get an idea of the ASP. Both are patterns trying to separate presentation and business logic, decoupling business logic from UI aspects. That means that in MVP standard web form page life cycle is just enhanced by extracting the business logic from code behind. In other words, page is the one servicing http request. MVC on other hand changes completely the game because the request gets intercepted by controller class before page is loaded, the business logic is executed there and then at the end result of controller processing the data just dumped to the page "view" In that sense, MVC looks at least to me a lot to Supervising Controller flavor of MVP enhanced with routing engine.
If one would consider himself good in web forms, I would suggest MVP. If one would feel not so comfortable in things such as page life cycle etc MVC could be a way to go here. I would say that MVP in this scenario is a quick win. In MVP you can have a single view working with multiple types of presenters and a single presenter working with different multiple views.
So, if for example, the model is a car, then the presenter is some sort of a car presenter, exposes the car properties year, maker, seats, etc. The view knows that the text field called 'car maker' needs to display the presenter Maker property. You can then bind to the view many different types of presenter, all must have Maker property - it can be of a plane, train or what ever , the view doesn't care.
The view draws data from the presenter - no matter which - as long as it implements an agreed interface.
MVC is great, but the problem is that usually its controller per view. Controller A knows how to set fields of View A. At this level of granularity, MVP makes little sense. When one on the contrary go to larger scales, proper interface becomes more important, the same with unambiguous assignment of responsibilities, and here comes MVP. On the other hand, this scale rule of a thumb, may weight very little when the platform characteristics favours some kind of relations between the components, like with the web, where it seems to be easier to implement MVC, more than MVP.
The article also matches what Uncle Bob Martin said in his one of his talks: that MVC was originally designed for the small UI components, not for the architecture of the system. In brief, it is. The simplest answer is how the view interacts with the model.
In MVP the view is updated by the presenter, which acts as as intermediary between the view and the model. The presenter takes the input from the view, which retrieves the data from the model and then performs any business logic required and then updates the view.
In MVC the model updates the view directly rather than going back through the controller. IMO, MVP is an improved version of MVC where you basically separate the concern of what you're gonna show the data from how you're gonna show the view. The presenter includes kinda the business logic of your UI, implicitly imposes what data should be presented and gives you a list of dumb view models.
And when the time comes to show the data, you simply plug your view probably includes the same id's into your adapter and set the relevant view fields using those view models with a minimum amount of code being introduced just using setters. In MVC, we talk through interfaces boundaries to glue different layers. A controller is a plug-in to our architecture but it has no such a restriction to impose what to show. An action is performed on the Controller , which will execute an action on the Model.
That action in the Model , will trigger a reaction in the View. The View , is always updated when the Model 's state changes. MVC wasn't originally created for the Web, but for Desktop applications instead, where the Controller, Model and View would co-exist together. Because we use web frameworks eg:. Laravel that still use the same naming conventions model-view-controller , we tend to think that it must be MVC, but it's actually something else.
Instead, have a look at Action-Domain-Responder. So far, the same. When a new action is requested on the same component, the Controller is called again, and the cycle repeats itself. Note: Wikipedia states that " Each ADR action, however, is represented by separate classes or closures. This is not necessarily true. Several Actions can be in the same Controller, and the pattern is still the same.
In MVC, the Controller is the one in charge! It communicates with the Model to get the appropriate data. Then, it shows a new View that resembles the profile page. The Controller may take the data from the Model and feed it directly to the View -as proposed in the above diagram- or let the View fetch the data from the Model itself. In MVP, the View is the one in charge! The Presenter will do the required logic and any needed communication with the Model then, calls back the View through its interface so that the View can display that the save has been completed.
This came to a picture in early where Microsoft introduced Smart Client windows applications. A presenter is acting as a supervisory role in MVP which binding View events and business logic from models. The view is the initiator for user inputs and then delegates the events to the Presenter and the presenter handles event bindings and gets data from models. Pros: The view is having only UI not any logics High level of testability. Controller is responsible for creating models and rendering views with binding models.
Cons: Sometimes too much workload for Controllers, if try to render multiple views in same controller. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Ask Question. Asked 13 years, 3 months ago. Active 15 days ago. Viewed k times. Improve this question. Mike Minutillo Mike Minutillo Each button, label, etc, had its' own view and controller object, or at least that is what Uncle Bob claims.
I think he was talking about Smalltalk. Look up his talks on YouTube, they are fascinating. It just notifies the View to get the data from the Model itself.
The Presenter itself gets any data needed from the Model and passes it to the View to show. More to this together with an android sample in all architecture patterns is here: digigene.
They are called architectural patterns not design patterns. If you want to know the difference, check this — Hasan El-Hefnawy. Add a comment. Active Oldest Votes. Two primary variations Passive View: The View is as dumb as possible and contains almost zero logic. Pro: maximum testability surface; clean separation of the View and Model Con: more work for example all the setter properties as you are doing all the data binding yourself.
Pro: by leveraging data binding the amount of code is reduced. Con: there's a less testable surface because of data binding , and there's less encapsulation in the View since it talks directly to the Model. Model-View-Controller In the MVC , the Controller is responsible for determining which View to display in response to any action including when the application loads.
Presentation Model One other pattern to look at is the Presentation Model pattern. Improve this answer. Can you please clarify this phrase? To me, it sounds like the same thing, but I'm sure you're describing something different. Panzercrisis I'm not sure if this is what the author meant, but this is what I think they were trying to say.
Like this answer - stackoverflow. In MVP, the presenter is coupled closer to the view, and usually results in a mapping that is closer to one-to-one, i. You typically wouldn't map another view's actions to another presenter's from another view method.
Note that MVC is often used by web-frameworks like Laravel , where the received URL requests maybe made by users are handled by the Controller and the HTML generated by the View is sent to the client -- So, the View is a part of the backend and the user can never access it directly, and if you experience anywhere the opposite then consider that as an MVC-extension or even violation.
What the author describes when speaking about MVC isn't the original Smalltalk MVC whose flow is triangular but the "Web MVC" where the controller renders a view using a model and returns it to the user. I believe this is worth noting because this creates a lot of confusion. Phyxx Phyxx This is a great depiction of the schematic, showing the abstraction and complete isolation of any GUI related view stuff from the API of the presenter.
One minor point: A master presenter could be used where there is only one presenter, rather than one per view, but your diagram is the cleanest. Thus the interfaces, needing to be there, to inject that state. Good picture. I use MVP quite a lot, so I'd like to make one point.
In my experience, the Presenters need to talk to one another quite often. Same is true for the Models or Business objects. Because of these additional "blue lines" of communication that would be in your MVP pic, the Presenter-Model relationships can become quite entangled. Therefore, I tend to keep a one-to-one Presenter-Model relationship vs. Yes, it requires some additional delegate methods on the Model, but it reduces many headaches if the API of the Model changes or needs refactoring.
The MVC example is wrong; there's a strict relationship between views and controllers. By definition, a controller interprets human gesture input to produce events for the model and view alike for a single control.
More simply, MVC was intended for use with individual widgets only. One widget, one view, one control. Falvo II. StuperUser -- Not sure what I was thinking when I wrote that. You're right, of course, and looking back on what I wrote, I have to wonder if I had some other context in mind which I failed to articulate.
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