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):||13 April 2011|
|PDF File Size:||10.49 Mb|
|ePub File Size:||3.16 Mb|
|Price:||Free* [*Free Regsitration Required]|
Building GWT Applications with MVP and Issues with Overlay Types
When UI elements in the view are updated, they notify the presenter to change the model. This method we set up to simply parse the history token to determine what view is requested, and then is required, and will call one of the do methods in 3, if the history token is recognized and an action can be determined. Modify presenters and services so a callback can be set that is gutorial test-friendly. Also, watch this presentation by Ray Ryan. In addition, if we wanted to run this application within a mobile browser we could switch out the views without having to change any of the surrounding application code.
The actual actions do not change. But without an implementation, they are not going to do much! Advanced Mp Commands [Cheat Sheet]. Technically there is no reason not to make the presenter listen for events from the view widgets. Over a million developers have joined DZone. Remember, test driven development is your friend.
This is not a requirement nvp makes our lives easier.
Introduction to the MVP pattern: a GWT example | G-Widgets
Nice words, but what does it mean? Building tutoriql MVP-based application can be straightforward and easy once you understand the fundamentals behind this design pattern. View These are the UI components that display model data and send user commands back to the presenter component.
Model A model encompasses business objects, and in the case of our Contacts application we have: The Event Bus is a mechanism for a passing events and b registering to be notified of some subset of these events.
This component contains the history management and view transition logic. We will call this the Application Controller or AppController for short. Learn how to refactor a monolithic application to work your way toward a scalable and resilient ttutorial. We will also make use of an EventBus. Building any large scale application has its hurdles, and GWT apps are no exception.
That is because we agreed that all of that should appear only in the presenter. Interesting Readings about MVP: The data being displayed is directly tied to the complexity of uttorial model. Throughout the two photo app projects, you will see us use a ClientFactory object.
We do that in the AppController class, as shown in listing 2. For that, we need to control the application.
We implement that as a very simple mock-up component that reads data from a file and. Google have updated their large scale web application development series with a sample application and extensive documentation that demonstrates their new MVP support in GWT 2. The most common one is to indicate in gwr browser URL the tutofial view required, usually via a token on the URL, ttutorial then to react to that.
The next three sections will look at each of those in turn, starting with the generic interface. App-wide events are tuorial the only events that you want to be passing around on the Event Bus. And this brings us to the discussion of those presenters. So, our view is dumb and contains zero application logic. For simplicity, this object contains a first name, last name, and email address. In our PhotoApp, we will have one very simple model: Multiple components can be listening for a single event, so when an event is fired using the EventBus.
However, The view can directly invoke functionalities from the model such as checking a value from the database or making a calculation. So how do we fix this?
Regardless of which one was chosen, I was also gutorial with deciding if we should use an existing framework or write our own. In the first example, the implementations are verbose as we have a lot of boilerplate code; in the second, we have swapped the view implementation for UiBinder versions.
PhotoListPresenter – drives the thumbnail view. Implementing the MVP pattern itself was relatively straightforward, but I did encounter a few issues. One of the more integral parts of any web app is the handling of history events.
We are going to make each view implements the Display interface of its presenter:.