Architecting your Google Web Toolkit GWT apps with Model View Presenter ( MVP) At its core, MVP is a design pattern that breaks your app up into the. Main Components of GWT MVP. Framework. • Model. – Responsible for holding raw data. – No business logic allowed (just like any model really). • Example. Modular design for large-scale apps, similar to the widely-accepted MVC approach in “normal” Web applications.
|Published (Last):||2 November 2015|
|PDF File Size:||3.52 Mb|
|ePub File Size:||10.5 Mb|
|Price:||Free* [*Free Regsitration Required]|
This means it needs to implement the go and bind method from Presenter as well as the onUpdateTitle from PhotoDetailsPresenter.
History events are token strings that represent some new state within your application. The beauty of using setData is that changes to the model can be made without updating the view code.
However, The view can directly invoke functionalities from the model such as checking a value from the database or making a calculation.
The data being displayed is directly tied to the complexity of our model. The reason being is that the app is really only concerned when some state has changed contact values changed, contact deleted, etc…which is the case after the RPC has returned.
It should be just Tutoril components that the presenter can access to set or get values from. And, where you do need to test your views, those tests should be few and far between and, in many instances, simply integration testing being driven by Selenium or some Selenium-like testing suite. Given that history is not specific to a particular view, it makes sense to add it to the AppController class. Implementing the MVP pattern itself was relatively straightforward, but I did encounter a few issues.
The most common one is to indicate in the browser URL the new view required, usually via a token on the URL, and then tutirial react to that. I suggest you to read the different post and the questions and answers from the comments because they are quite enlightening. Below is an example of the event that is fired upon successfully updating a contact. Blindly dumping all of the possible events within your app on the Event Bus can lead to chatty applications hwt get bogged down in event handling.
This content is being reproduced here by permission from Manning Publications. Each specific view needs to be described individually, and for that, we create first a new interface. What is their use then? In order for ywt app to do something meaningful, the presenter is going to need to:. Our hwt will have data filled from a server component.
MVP Architecture for GWT Application
And this brings us to the discussion of those presenters. The concept is that a presenter creates its associated view and requests the view to be populated with appropriate data from the model. A presenter contains all of the logic for our Contacts application, including history managementview transition and data sync via RPCs back to the server.
This means each view will implement the asWidget method, which we will have to implement so that it returns a representation of the view that is a widget.
The last solution seems like best one, but I’m also curious to know what others are doing. Alexander Pogrebnyak 38k 8 85 Click here to view the complete list of archived articles.
In our photo application, this means we will have the following three presenters: Our view specific interfaces detail exactly what can be expected from the view. Learn how to refactor a monolithic application to work your way toward a scalable and resilient microsystem. Again, there is no requirement to do this; it is just good to have.
This is not a requirement to have, but suits us well as it creates a basic contract that all our views will adhere to, and that other components are aware of and mp trust. If the bulk of the code within your app is encompassed within a presenter, and that presenter relies strictly on JRE-based components, you can build the majority of your test cases as efficient, vanilla JUnit tests. Within the constructor, we also call the bind method from the Presenter interface. This is where I ran into a major issue that I don’t have a solution for.
Below is a list of the events that we have defined. To help sort things hwt we introduce design patterns to create compartmentalized areas of responsibility within our project.
Building GWT Applications with MVP and Issues with Overlay Types
So long as we wrap a view in a display interface that can be mocked and our JRE tests never call asWidgetall is grand.
Download the eBook instantly from manning. A light version of the Contact that contains only the unique identifier and display name.
This seems to work, but my View interface has a lot of void methods, which is a bit different than standard MVP patterns I’ve seen. It turns out that our implementation of the PhotoDetailsView interface is pretty simple.
Binding presenters and views Events and the event bus History and view transitions Testing Sample Project The sample project, referenced throughout this tutorial, can be found at Tutorial-Contacts. The AppController is also used to instantiate the application. Regardless of which one was chosen, I was also tasked with deciding if we should use an existing framework or write our own.
I’m writing this post to see if anyone has solved these issues. Interesting Readings about MVP: