Why does the model directly update the view in the MVC pattern? - model-view-controller

I've been learning how to build web applications with Laravel and Vue.js and I understand the part where the user uses the view in order to send requests to the controller which then manipulates the model. I absolutely see that flow in my applications.
What I am not so sure about is why in MVC diagrams like this one: MVC pattern diagram from Wikipedia. The model directly updates the view but in my applications it seems that the Controller is the one that gets the changes from the model and sends that to the view (via HTTP).
Is there something that I don't quite understand?

In this diagram view is a representation of model. when model changes view changes to represent the model. in a real MVC application controller may send model to view (this model is called view-model which is a special type of model and it may get populated dynamically by controller using back end model). Some MVC applications have two types of models a model (which may be a database for back end) and a model (called view-model which is for representation and will be send to view). For example ASP.NET MVC has this type of view-model.
What is ViewModel in MVC?
https://en.wikipedia.org/wiki/Model–view–viewmodel

Related

What all things can be stuffed inside a controller in MVC?

I was going through the articles describing the MVC pattern. None of them were clear on explaining the role of Controller in MVC. Some says Controller can make changes to the view such as disabling a button or changing the text color whereas some says any changes to the view should be done inside view only. Can you please give me tips on the following question?
1) Can any change pertaining to the view be done inside the controller?
2) What not should be written inside a controller?
3) It is right to say "View should do all the changes by itself when a new recordset is generated by the model, as the view queries model directly, and controller is not involved in this transaction?"
4) I have heard this statement about MVC "In current version of windows application development. View is capable to handle the event(like button press) and the controller is called when needed.It is stupid to delegate the event listening to the controller now." Doesn't this sound more like a MVP?
Thanks. Hoping to get some help here.
In my opinion:
1) The controller changes the data provided to the view, so in a way, yes. The view should just manage the presentation of the data provided to it by the controller.
2) The controller should contain all code to handle any actions taken by the user. Depending on the size of your application, the controller can hand the action off to a business layer to do the work then gather view data once the business layer is complete and hand it back to the view. Or, if you don't have a business layer, it can do the work directly.
3) In true MVC, the view should not have access to the model directly. The controller should create view objects from the model and pass them to the view. In any case, the view should never do any real work other than presentation.
4) I don't know MVP so cannot answer this question.
1) Controller responsibility is primarily "execute an action, choose an appropriate view, provide some data to that view and return the view to a user".
2) As MVC tries to separate presentation logic and UI rendering, I believe, controller shouldn't attempt to perform any of view responsibilities: listening to UI events or pre-formatting of values dateString = data.ToString('YYYY-MM') - that's all should go to view.
3) in MVC view knows all about a model - model is rendered by view without any controller involvement (that's primary 'issue' fixed by MVP, where view should and model should unbound as much as possible). However it's not recommended for view to query model directly. Instead, all data changes should be reported to view by model using Observer pattern.
Consider the following -
schema from wikipedia article - dashed line from model to view indicates that fact. Just keep in mind that model is more viewmodel here and shouldn't really be a part of BL layer.
So here scenario could be the following:
User clicks "add item"
View sends request to the controller with the item data
Controller makes call to BL, which makes changes to the model (adds new item to the list).
Model fires "updated" event to the view (or "error" event, if there are some issues in underlying layers)
View updates UI according to changes reported.
4) The statement is perfectly true. In MVC you shouldn't do that. I assume, in MVP you shouldn't do that as well - I mean, listening to events from UI directly. That should be done either by forwarding event by view; or using a platform-independent view representation, like
inderface IMyGridView
{
event ItemEvent AddItemClick;
}
(which doesn't make sense for MVC, as view is pretty much independent from a controller and mostly all view actions are result in calls to controller).

Is the GEF really a MVC framework?

in the tutorials from http://www.vainolo.com/tutorials/ the position of the model is saved in the model. I want to save all data to file and want to get the same view, when I load the file.
Searching for an answer for this question, I got another more important question:
Is the GEF really a MVC framework?
GEF Controllers tells the mvc controller role is taken from the EditPart. It creates the specified objects.
Regarding the examples the controller holds view parts, but the mvc pattern tells, that the controller only reacts on user interaction and tells the view, it has to update or what ever.
Concluding on it the following code is wrong, because it is part of EditPart and it changes:
public void refreshVisuals(){
IPersonFigure figure = (IPersonFigure)getFigure();
Person model = (Person)getModel();
figure.setName(model.getName());
figure.setSurname(model.getSurname());
}
Regarding wikipedia the view has an observer on the model, so the following sentence from GEF is wrong, isn't it?
The EditPart syncs the actual model state to the view and implements the observer.
In the MVC pattern, the controllers must listen to the changes of the model. In GEF, EditParts are the controllers so they must listen to their model to update the view according to the new state of the model.
So what is correct?
To prevent cross-posting have a look on http://www.eclipse.org/forums/index.php/m/755178/.
The wikipedia states a the start of the article on MVC that " MVC comes in different flavors (MVC overview). Sometimes the view can read the model directly and update itself, sometimes this is done by the controller.
The primary concept that MVC provides is decoupling the presentation from the view, which should contain no logic. Changes to the model are executed by the controllers, and changes to the view are caused when the model is changed. But this does not mean that the controller can't be the one who updates the view when the model changes. Someone has to do it, right? I personally think that having the view directly read from the model is not a good practice since it makes them too dependent, and that model and view should be completely separated. This is great when you have to make changes in your model (for example a field is changed from being real to being calculated) - you don't have to change your view (but you may have to change your controller, but this is normally easier).
Hope this clears things up for you.

Relations between elements of MVC

Can someone explain the relations between elements of MVC (with the active model), painted on this picture?
I see it like this:
Controller → Model — a model's data changing by the controller.
Model → View — the model notifies the view about changing.
View → Model — the view get data from the model.
View → Controller — the view notifies the controller about user's actions (for example, button pressing).
Controller → View — but this relation, as I think, is unnecessary and contradict MVC rule about developing the controller independent from the view: it should interacts through the model.
The MVC is rather broad subject, there are many variants of this pattern, and many implementations. I have seen solutions in which one of the responsibilities of a controller was to create an instance of a View with associated Model attached. This might be the relation you're looking for.
One other thing - existence of controllers independent from the view is a myth in real-life scenarios, in my opinion. Sooner or later you need to provide a functionality which explicitly tightens the View - Controller relation and is unusable (or simply different) without that particular View. Besides it is far more efficient to embrace the fact that different types of views behave differently and turn this into advantage by building tailored Controllers instead of pretending that we could deal with every aspect of user interaction with just one.
I think the relation between the between the model and view is wrong (at least the solid one). The way I see it in an MVC pattern is that everything goes via the controller. So in the view, the user selects the data he wants to see.This request is send to the controller. The controller is going to get the data in the model and the model gives back the requested data. The controller then sends it back to the view and the view outputs it to the user.
As for the controller->view relationship you have highlighted
The controller needs to be able to choose the appropriate view that is displayed
AFAIK, that is the only relationship the controller has with the view (aside for the view routing messages to the controller). MVC is a little different from MVVM/MVP because you don't necessarily have just one view for each controller. For example, you could have a user controller and you might have a view for displaying information, one for editing users, and one for adding users. With the other two methods, there is a one to one relationship between views and ViewModels or Presenters.
Controllers being independent of the view is not a myth
Maybe I haven't used MVC enough in other scenarios but I have always kept the controller independent of the view. In fact if you have any view code in your controller (ie function with ListBoxEventArgs, referring to view components, etc) then you have not achieved the goal of this pattern which is to separate your view from your logic and model. I believe ASP.NET MVC makes views completely independent of the controller by having some class that manage tracking the initiated views. This class is available to all the controllers (through inheritance but dependency injection is fine too) and then each controller just picks a view to display using this class. The view can be selected with a constant or a string (in fact, I believe it is even possible to select them with no argument and based on the method name).
view->controller relationship
With ASP.NET MVC, view's are independent of the controller too since events are routed to the controller via url. However. in other non-web situations, it is fine to just forward your events to the controller by directly calling controller methods in the code behind.
Implementation details
On my blog, I wrote an article that covers the implementation of MVC a bit and should help answer your questions.
MVVM vs MVP vs MVC: The differences explained
Personally, I think the type of MVC shown in your diagram is not being employed as often today as in the past and it might be hard to find examples that use those relationships as shown. The reason is that if the view is able to talk to the model, then I think developers will opt for MVP or MVVM (and use a view model) over MVC. The only case I can think of where the view is not able to continuously talk to the model is in server client situations. In this case, there are many popular MVC frameworks like ASP.NET MVC is still popular today.

Programming Pattern: MVC vs MVP

I'm a little bit confused about these two programming patters: MVC and MVP.
Which are the main differences between them?; I have been searching on the net and I made a couple of examples of both of them, but I'm even more confused, because in some sample web pages MVP uses more than 2 interfaces to communicate the presenter with the view layer (some ones even have completely blank interfaces, only declarated), but in other ones it only takes two interfaces to transport data from presenter to view. Which is the correct way of applying that pattern?
On the other hand, I have been working on MVC for a while, but until now, I realize that maybe I had been aplying the pattern in the wrong way. I have had this:
Model: C# classes that behaves like the bussiness objects.
Controller: C# classes that uses the model objects to fill them or manipulate them.
View: C# aspx pages to show the model objects; the controller is the responsible of sending the model objects to this layer after manipulating and/or filling them with data.
I hope you can clear my doubts. Thanks in advance.
MVC
View is responsible for rendering the UI elements. The controller responds to the UI actions. And the model handles the business behavior. The controller is responsible for which view want to display. The whole business logic layer can be represented by the Model. The view and the model are tightly coupled.
MVP
View is responsible for rendering the UI elements. The role of controller is replaced with a presenter. The presenter mediates the actions between both models and views. There isnt a mechanism for binding views to view models. So we rely on each view implementing an interface with the view

What are MVP and MVC and what is the difference?

Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted.
When looking beyond the RAD (drag-drop and configure) way of building user interfaces that many tools encourage you are likely to come across three design patterns called Model-View-Controller, Model-View-Presenter and Model-View-ViewModel. My question has three parts to it:
What issues do these patterns address?
How are they similar?
How are they different?
Model-View-Presenter
In MVP, the Presenter contains the UI business logic for the View. All invocations from the View delegate directly to the Presenter. The Presenter is also decoupled directly from the View and talks to it through an interface. This is to allow mocking of the View in a unit test. One common attribute of MVP is that there has to be a lot of two-way dispatching. For example, when someone clicks the "Save" button, the event handler delegates to the Presenter's "OnSave" method. Once the save is completed, the Presenter will then call back the View through its interface so that the View can display that the save has completed.
MVP tends to be a very natural pattern for achieving separated presentation in WebForms. The reason is that the View is always created first by the ASP.NET runtime. You can find out more about both variants.
Two primary variations
Passive View: The View is as dumb as possible and contains almost zero logic. A Presenter is a middle man that talks to the View and the Model. The View and Model are completely shielded from one another. The Model may raise events, but the Presenter subscribes to them for updating the View. In Passive View there is no direct data binding, instead, the View exposes setter properties that the Presenter uses to set the data. All state is managed in the Presenter and not the View.
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.
Supervising Controller: The Presenter handles user gestures. The View binds to the Model directly through data binding. In this case, it's the Presenter's job to pass off the Model to the View so that it can bind to it. The Presenter will also contain logic for gestures like pressing a button, navigation, etc.
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. This differs from MVP where actions route through the View to the Presenter. In MVC, every action in the View correlates with a call to a Controller along with an action. In the web, each action involves a call to a URL on the other side of which there is a Controller who responds. Once that Controller has completed its processing, it will return the correct View. The sequence continues in that manner throughout the life of the application:
Action in the View
-> Call to Controller
-> Controller Logic
-> Controller returns the View.
One other big difference about MVC is that the View does not directly bind to the Model. The view simply renders and is completely stateless. In implementations of MVC, the View usually will not have any logic in the code behind. This is contrary to MVP where it is absolutely necessary because, if the View does not delegate to the Presenter, it will never get called.
Presentation Model
One other pattern to look at is the Presentation Model pattern. In this pattern, there is no Presenter. Instead, the View binds directly to a Presentation Model. The Presentation Model is a Model crafted specifically for the View. This means this Model can expose properties that one would never put on a domain model as it would be a violation of separation-of-concerns. In this case, the Presentation Model binds to the domain model and may subscribe to events coming from that Model. The View then subscribes to events coming from the Presentation Model and updates itself accordingly. The Presentation Model can expose commands which the view uses for invoking actions. The advantage of this approach is that you can essentially remove the code-behind altogether as the PM completely encapsulates all of the behavior for the view. This pattern is a very strong candidate for use in WPF applications and is also called Model-View-ViewModel.
There is a MSDN article about the Presentation Model and a section in the Composite Application Guidance for WPF (former Prism) about Separated Presentation Patterns
This is an oversimplification of the many variants of these design patterns, but this is how I like to think about the differences between the two.
MVC
MVP
I blogged about this a while back, quoting on Todd Snyder's excellent post on the difference between the two:
Here are the key differences between
the patterns:
MVP Pattern
View is more loosely coupled to the model. The presenter is
responsible for binding the model to
the view.
Easier to unit test because interaction with the view is through
an interface
Usually view to presenter map one to one. Complex views may have
multi presenters.
MVC Pattern
Controller are based on behaviors and can be shared across
views
Can be responsible for determining which view to display
It is the best explanation on the web I could find.
Here are illustrations which represent communication flow
MVP is not necessarily a scenario where the View is in charge (see Taligent's MVP for example).
I find it unfortunate that people are still preaching this as a pattern (View in charge) as opposed to an anti-pattern as it contradicts "It's just a view" (Pragmatic Programmer). "It's just a view" states that the final view shown to the user is a secondary concern of the application. Microsoft's MVP pattern renders re-use of Views much more difficult and conveniently excuses Microsoft's designer from encouraging bad practice.
To be perfectly frank, I think the underlying concerns of MVC hold true for any MVP implementation and the differences are almost entirely semantic. As long as you are following separation of concerns between the view (that displays the data), the controller (that initialises and controls user interaction) and the model (the underlying data and/or services)) then you are achieving the benefits of MVC. If you are achieving the benefits then who really cares whether your pattern is MVC, MVP or Supervising Controller? The only real pattern remains as MVC, the rest are just differing flavours of it.
Consider this highly exciting article that comprehensively lists a number of these differing implementations.
You may note that they're all basically doing the same thing but slightly differently.
I personally think MVP has only been recently re-introduced as a catchy term to either reduce arguments between semantic bigots who argue whether something is truly MVC or not or to justify Microsofts Rapid Application Development tools. Neither of these reasons in my books justify its existence as a separate design pattern.
MVP: the view is in charge.
The view, in most cases, creates its presenter. The presenter will interact with the model and manipulate the view through an interface. The view will sometimes interact with the presenter, usually through some interface. This comes down to implementation; do you want the view to call methods on the presenter or do you want the view to have events the presenter listens to? It boils down to this: The view knows about the presenter. The view delegates to the presenter.
MVC: the controller is in charge.
The controller is created or accessed based on some event/request. The controller then creates the appropriate view and interacts with the model to further configure the view. It boils down to: the controller creates and manages the view; the view is slave to the controller. The view does not know about the controller.
MVC (Model View Controller)
The input is directed at the Controller first, not the view. That input might be coming from a user interacting with a page, but it could also be from simply entering a specific url into a browser. In either case, its a Controller that is interfaced with to kick off some functionality.
There is a many-to-one relationship between the Controller and the View. That’s because a single controller may select different views to be rendered based on the operation being executed.
Note the one way arrow from Controller to View. This is because the View doesn’t have any knowledge of or reference to the controller.
The Controller does pass back the Model, so there is knowledge between the View and the expected Model being passed into it, but not the Controller serving it up.
MVP (Model View Presenter)
The input begins with the View, not the Presenter.
There is a one-to-one mapping between the View and the associated Presenter.
The View holds a reference to the Presenter. The Presenter is also reacting to events being triggered from the View, so its aware of the View its associated with.
The Presenter updates the View based on the requested actions it performs on the Model, but the View is not Model aware.
For more Reference
There are many answers to the question, but I felt there is a need for some really simple answer clearly comparing the two. Here's the discussion I made up when a user searches for a movie name in an MVP and MVC app:
User: Click click …
View: Who’s that? [MVP|MVC]
User: I just clicked on the search button …
View: Ok, hold on a sec … . [MVP|MVC]
( View calling the Presenter|Controller … ) [MVP|MVC]
View: Hey Presenter|Controller, a User has just clicked on the search button, what shall I do? [MVP|MVC]
Presenter|Controller: Hey View, is there any search term on that page? [MVP|MVC]
View: Yes,… here it is … “piano” [MVP|MVC]
Presenter|Controller: Thanks View,… meanwhile I’m looking up the search term on the Model, please show him/her a progress bar [MVP|MVC]
( Presenter|Controller is calling the Model … ) [MVP|MVC]
Presenter|Controller: Hey Model, Do you have any match for this search term?: “piano” [MVP|MVC]
Model: Hey Presenter|Controller, let me check … [MVP|MVC]
( Model is making a query to the movie database … ) [MVP|MVC]
( After a while ... )
-------------- This is where MVP and MVC start to diverge ---------------
Model: I found a list for you, Presenter, here it is in JSON “[{"name":"Piano Teacher","year":2001},{"name":"Piano","year":1993}]” [MVP]
Model: There is some result available, Controller. I have created a field variable in my instance and filled it with the result. It's name is "searchResultsList" [MVC]
(Presenter|Controller thanks Model and gets back to the View) [MVP|MVC]
Presenter: Thanks for waiting View, I found a list of matching results for you and arranged them in a presentable format: ["Piano Teacher 2001","Piano 1993"]. Please show it to the user in a vertical list. Also please hide the progress bar now [MVP]
Controller: Thanks for waiting View, I have asked Model about your search query. It says it has found a list of matching results and stored them in a variable named "searchResultsList" inside its instance. You can get it from there. Also please hide the progress bar now [MVC]
View: Thank you very much Presenter [MVP]
View: Thank you "Controller" [MVC]
(Now the View is questioning itself: How should I present the results I get from the Model to the user? Should the production year of the movie come first or last...? Should it be in a vertical or horizontal list? ...)
In case you're interested, I have been writing a series of articles dealing with app architectural patterns (MVC, MVP, MVVP, clean architecture, ...) accompanied by a Github repo here. Even though the sample is written for android, the underlying principles can be applied to any medium.
Model-View-Controller
MVC is a pattern for the architecture of a software application. It separate the application logic into three separate parts, promoting modularity and ease of collaboration and reuse. It also makes applications more flexible and welcoming to iterations.It separates an application into the following components:
Models for handling data and business logic
Controllers for handling the user interface and application
Views for handling graphical user interface objects and presentation
To make this a little more clear, let's imagine a simple shopping list app. All we want is a list of the name, quantity and price of each item we need to buy this week. Below we'll describe how we could implement some of this functionality using MVC.
Model-View-Presenter
The model is the data that will be displayed in the view (user interface).
The view is an interface that displays data (the model) and routes user commands (events) to the Presenter to act upon that data. The view usually has a reference to its Presenter.
The Presenter is the “middle-man” (played by the controller in MVC) and has references to both, view and model. Please note that the word “Model” is misleading. It should rather be business logic that retrieves or manipulates a Model. For instance: If you have a database storing User in a database table and your View wants to display a list of users, then the Presenter would have a reference to your database business logic (like a DAO) from where the Presenter will query a list of Users.
If you want to see a sample with simple implementation please check
this GitHub post
A concrete workflow of querying and displaying a list of users from a database could work like this:
What is the difference between MVC and MVP patterns?
MVC Pattern
Controller are based on behaviors and can be shared across views
Can be responsible for determining which view to display (Front Controller Pattern)
MVP Pattern
View is more loosely coupled to the model. The presenter is responsible for binding the model to the view.
Easier to unit test because interaction with the view is through an interface
Usually view to presenter map one to one. Complex views may have multi presenters.
MVP = Model-View-Presenter
MVC = Model-View-Controller
Both presentation patterns. They separate the dependencies between a Model (think Domain objects), your screen/web page (the View), and how your UI is supposed to behave (Presenter/Controller)
They are fairly similar in concept, folks initialize the Presenter/Controller differently depending on taste.
A great article on the differences is here. Most notable is that MVC pattern has the Model updating the View.
Also worth remembering is that there are different types of MVPs as well. Fowler has broken the pattern into two - Passive View and Supervising Controller.
When using Passive View, your View typically implement a fine-grained interface with properties mapping more or less directly to the underlaying UI widget. For instance, you might have a ICustomerView with properties like Name and Address.
Your implementation might look something like this:
public class CustomerView : ICustomerView
{
public string Name
{
get { return txtName.Text; }
set { txtName.Text = value; }
}
}
Your Presenter class will talk to the model and "map" it to the view. This approach is called the "Passive View". The benefit is that the view is easy to test, and it is easier to move between UI platforms (Web, Windows/XAML, etc.). The disadvantage is that you can't leverage things like databinding (which is really powerful in frameworks like WPF and Silverlight).
The second flavor of MVP is the Supervising Controller. 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.
The third "flavor" of MVP (or someone would perhaps call it a separate pattern) is the Presentation Model (or sometimes referred to Model-View-ViewModel). Compared to the MVP you "merge" the M and the P into one class. You have your customer object which your UI widgets is data bound to, but you also have additional UI-spesific fields like "IsButtonEnabled", or "IsReadOnly", etc.
I think the best resource I've found to UI architecture is the series of blog posts done by Jeremy Miller over at The Build Your Own CAB Series Table of Contents. He covered all the flavors of MVP and showed C# code to implement them.
I have also blogged about the Model-View-ViewModel pattern in the context of Silverlight over at YouCard Re-visited: Implementing the ViewModel pattern.
Both of these frameworks aim to seperate concerns - for instance, interaction with a data source (model), application logic (or turning this data into useful information) (Controller/Presenter) and display code (View). 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.
There is a discussion here regarding the differences between MVC vs MVP.
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.
MVP designs have the Presenter access the model and interact with the view.
Having said that, ASP.NET MVC is by these definitions an MVP framework because the Controller accesses the Model to populate the View which is meant to have no logic (just displays the variables provided by the Controller).
To perhaps get an idea of the ASP.NET MVC distinction from MVP, check out this MIX presentation by Scott Hanselman.
Both are patterns trying to separate presentation and business logic, decoupling business logic from UI aspects
Architecturally, MVP is Page Controller based approach where MVC is Front Controller based approach.
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. In other words, MVP IMHO is web form evolutionary type of enhancement.
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
Both of them enable TDD and have downsides and upsides.
Decision on how to choose one of them IMHO should be based on how much time one invested in ASP NET web form type of web development.
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.
Here's yet another blog post link giving a little bit more details on this topic
http://blog.vuscode.com/malovicn/archive/2007/12/18/model-view-presenter-mvp-vs-model-view-controller-mvc.aspx
I have used both MVP and MVC and although we as developers tend to focus on the technical differences of both patterns the point for MVP in IMHO is much more related to ease of adoption than anything else.
If I’m working in a team that already as a good background on web forms development style it’s far easier to introduce MVP than MVC. I would say that MVP in this scenario is a quick win.
My experience tells me that moving a team from web forms to MVP and then from MVP to MVC is relatively easy; moving from web forms to MVC is more difficult.
I leave here a link to a series of articles a friend of mine has published about MVP and MVC.
http://www.qsoft.be/post/Building-the-MVP-StoreFront-Gutthrie-style.aspx
In MVP the view draws data from the presenter which draws and prepares/normalizes data from the model while in MVC the controller draws data from the model and set, by push in the view.
In MVP you can have a single view working with multiple types of presenters and a single presenter working with different multiple views.
MVP usually uses some sort of a binding framework, such as Microsoft WPF binding framework or various binding frameworks for HTML5 and Java.
In those frameworks, the UI/HTML5/XAML, is aware of what property of the presenter each UI element displays, so when you bind a view to a presenter, the view looks for the properties and knows how to draw data from them and how to set them when a value is changed in the UI by the user.
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.) to the view. 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.
This binding framework, if you strip it down, it's actually the controller :-)
And so, you can look on MVP as an evolution of MVC.
MVC is great, but the problem is that usually its controller per view. Controller A knows how to set fields of View A. If now, you want View A to display data of model B, you need Controller A to know model B, or you need Controller A to receive an object with an interface - which is like MVP only without the bindings, or you need to rewrite the UI set code in Controller B.
Conclusion - MVP and MVC are both decouple of UI patterns, but MVP usually uses a bindings framework which is MVC underneath. THUS MVP is at a higher architectural level than MVC and a wrapper pattern above of MVC.
My humble short view: MVP is for large scales, and MVC for tiny scales. With MVC, I sometime feel the V and the C may be seen a two sides of a single indivisible component rather directly bound to M, and one inevitably falls to this when going down‑to shorter scales, like UI controls and base widgets. 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.
I think this image by Erwin Vandervalk (and the accompanying article) is the best explanation of MVC, MVP, and MVVM, their similarities, and their differences. The article does not show up in search engine results for queries on "MVC, MVP, and MVVM" because the title of the article does not contain the words "MVC" and "MVP"; but it is the best explanation, I think.
(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)
There are many versions of MVC, this answer is about the original MVC in Smalltalk. In brief, it is
This talk droidcon NYC 2017 - Clean app design with Architecture Components clarifies it
MVC (Model-View-Controller)
In MVC, the Controller is the one in charge! The Controller is triggered or accessed based on some events/requests then, manages the Views.
Views in MVC are virtually stateless, the Controller is responsible for choosing which View to show.
E.g.: When the user clicks on the “Show MyProfile” button, the Controller is triggered. 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.
MVP (Model-View-Presenter)
In MVP, the View is the one in charge! each View calls its Presenter or has some events that the Presenter listens to.
Views in MVP don’t implement any logic, the Presenter is responsible for implementing all the logic and communicates with the View using some sort of interface.
E.g.: When the user clicks the “Save” button, the event handler in the View delegates to the Presenter’s “OnSave” method. 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.
MVC vs. MVP
MVC doesn’t put the View in charge, Views act as slaves that the Controller can manage and direct.
In MVC, Views are stateless contrary to Views in MVP where they are stateful and can change over time.
In MVP, Views have no logic and we should keep them dumb as possible. On the other hand, Views in MVC may have some sort of logic.
In MVP, the Presenter is decoupled from the View and talks to it through an interface. This allows mocking the View in unit tests.
In MVP, Views are completely isolated from the Model. However, in MVC, Views can communicate with the Model to keep it up with the most
up-to-date data.
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.
There is this nice video from Uncle Bob where he briefly explains MVC & MVP at the end.
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). Its main benefit is you can test your UI business logic against many/various views like showing items in a horizontal list or vertical list.
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. In that sense, MVP is kind of an MVC with a concept of views being pluggable to the controller over adapters.
I hope this helps better.
You forgot about Action-Domain-Responder (ADR).
As explained in some graphics above, there's a direct relation/link between the Model and the View in MVC.
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.
Some people keep forgetting, that MVC was created in the late 70", and that the Web was only created in late 80"/early 90".
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.
In ADR, the Controller gets an Action, which will perform an operation in the Model/Domain. So far, the same.
The difference is, it then collects that operation's response/data, and pass it to a Responder (eg:. view()) for rendering.
When a new action is requested on the same component, the Controller is called again, and the cycle repeats itself.
In ADR, there's no connection between the Model/Domain and the View (Reponser's response).
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.
mvc adr model-view-controller action-domain-responder
In a few words,
In MVC, View has the UI part, which calls the controller which in turn calls the model & model in turn fires events back to view.
In MVP, View contains UI and calls the presenter for implementation part. The presenter calls the view directly for updates to the UI part.
Model which contains business logic is called by the presenter and no interaction whatsoever with the view. So here presenter does most of the work :)
MVP
MVP stands for Model - View- Presenter. This came to a picture in early 2007 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.
View event binding will be implemented in the Presenter from a view interface.
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
Cons:
Bit complex and more work when implementing event bindings
MVC
MVC stands for Model-View-Controller. Controller is responsible for creating models and rendering views with binding models.
Controller is the initiator and it decides which view to render.
Pros:
Emphasis on Single Responsibility Principle
High level of testability
Cons:
Sometimes too much workload for Controllers, if try to render multiple views in same controller.

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