How to handle controller/views creation in a custom MVC - java

I'm on an application which should open a GUI specific commands.
I tried to implement a sort of MVC like that (simplified version) :
class View1 {
// Delegate gui framework
private Gui delegate;
private Consumer<String> nextButtonCallback;
private Model model;
public void open() {
// open the view here and populate it with model values
// onButtonClick invoke nextButtonCallback.accept("data");
}
}
class EditController1 {
private Model model;
public void start() {
}
private void openView1() {
View1 view = new View1(model);
view.nextButtonCallback= string -> {
// open a second view
view.close();
openView2();
};
view.open();
}
private void openView1() {
View2 view = new View2(model);
view.backButtonCallback = string -> {
// go back
view.close();
openView1();
};
view.open();
}
}
class Command {
private ModelService modelService;
public void onCommand1(String modelId) {
Model model = modelService.getModel(modelId);
EditController1 controller = new EditController1 (model);
controller.start();
}
}
Right now the controller is controlling several views and handling internal navigation (is that a good idea ?)
Now, lets say I have another controller (InfoController) which is opened by another command (infoCommand). I would like to open edition when clicking "edit" button. But since we are in the InfoController I can not open edit views.
Same with "back" button, how to know if InfoController should open info view when EditController views are closed ?
How should I handle navigation between internal and external views with this kind of controllers ?
Or how should I rework to make it better ? :)
Thanks

Related

How do I force the view class to reload in Vaadin Flow when navigating to the same view

Assuming my view is:
#Route(value="test")
public class TestView extends VerticalLayout implements BeforeEnterObserver {
public TestView() {
super();
// do some stuff.
new Button("Test", click -> getUI().ifPresent(ui -> ui.navigate("test")));
}
#Override
public void beforeEnter(BeforeEnterEvent event) {
// do some other stuff.
}
}
If I click on the Test button above then the constructor is not instantiated however the beforeEnter() method is called. In my case I would much prefer to instantiate the whole view class because the beforeEnter() method includes some logic and setup code that the view needs that if called twice can mess up the components. Specially the beforeEnter() does some checks and depending on the details may call different component rendering paths.
Please try the code below. It removes the view (navigation target) instance from UI and then calls page reload on the client side. Then, after page reload, the next request to server will force creating a new instance of the view.
#Route(value="test")
public class TestView extends VerticalLayout implements BeforeEnterObserver {
private final String uuid;
public TestView() {
super();
// do some stuff.
System.out.println("CTOR called");
uuid = UUID.randomUUID().toString();
final Element view = getElement();
Button button = new Button("Test", click -> {
getUI().ifPresent(ui -> ui.getPage().setLocation("test"));
view.removeFromParent();
});
add(button);
}
#Override
public void beforeEnter(BeforeEnterEvent event) {
// do some other stuff.
System.out.println("Before enter");
System.out.println("UUID = " + uuid);
}
}
Output:
CTOR called
Before enter
UUID = 74306acc-3771-4998-aa46-19834ca9e033
CTOR called
Before enter
UUID = dbc1be2a-1bee-4da7-b676-187208621569
Hope this is something you wanted to reach.
If you are using Spring with Vaadin, you can annotate the class with
#Component
#Scope("prototype")

JavaFX bind a hyperlink to a label

I am using MVP in my JavaFX application.
Resources:
public class InfoStageResources{
StringProperty lblBlogText;
Hyperlink linkBlog;
InfoStageResources() {
this.lblBlogText = new SimpleStringProperty("link");
this.linkBlog = new Hyperlink("link");
}
}
Controller:
public class InfoStageController{
private InfoStageView view;
private InfoStageResources res;
public void initView(){
this.res = new InfoStageResources();
this.view = new InfoStageView(this.res);
this.initViewBindings();
}
private void initViewBindings(){
this.view.lblBlog.textProperty().bind(this.res.lblBlogText);
//this will not work
this.view.lblBlog.textProperty().bind(this.res.linkBlog);
}
}
View
In my InfoStageView in just init my labels and style my view.
How can bind my Hyperlink to my label. I tried some things but without success.
My StringProperty lblBlogText isn't clickable but easy to bind.
My goal: I want to open the browser with the link.
I think you are looking for
this.view.lblBlog.textProperty().bind(this.res.linkBlog.textProperty());

GWT Updating Main Content using EventBus and ActivityMapper - Can GWT help me to do this cleaner?

I would like to know
Am I doing things (the following) too complicated?
Is there a better way to update the main content of an activity that allows me to bookmark the event calendar of a store via URL like #MainPlace:eventCalendar?storeId=<id>?
I'm having this ActivityMapper here
public class AppActivityMapper implements ActivityMapper {
private ClientFactory clientFactory;
private MainActivity mainActivity;
// ..
#Override
public Activity getActivity(Place place) {
if (place instanceof LoginPlace) {
return new LoginActivity((LoginPlace) place, clientFactory);
} else if (place instanceof MainPlace) {
if(this.mainActivity == null) {
this.mainActivity = new MainActivity((MainPlace) place, clientFactory);
} else {
this.mainActivity.updateMainContent(((MainPlace) place).getMainContentToken());
}
return this.mainActivity;
}
return null;
}
}
and a MainActivity that controls my MainView that is just a menu ond the left side and the main content on the right side.
I want to decouple my views like in Best Practices for Architecting GWT App which is why I'm trying to control the main content by using events that get fired as something gets clicked in my MenuView.
Therefore I am initializing some event handlers in my MainActivity that react to clicks on the buttons in my menu to delegate the update to the MainView.
public class MainActivity extends AbstractActivity implements MainView.MainPresenter {
#Override
public void start(AcceptsOneWidget panel, EventBus eventBus) {
this.mainView = this.clientFactory.getMainView();
this.mainView.setPresenter(this);
this.mainView.initialize();
this.eventBus = eventBus;
this.eventBus.addHandler(HomeClickedEvent.TYPE, new HomeClickedHandler() {
#Override
public void onHomeClicked(HomeClickedEvent event) {
goTo(new MainPlace("home"));
}
});
this.eventBus.addHandler(EventCalendarClickedEvent.TYPE, new EventCalendarClickedHandler() {
#Override
public void onEventCalendarClicked(EventCalendarClickedEvent eventCalendarClickedEvent) {
goTo(new MainPlace("eventCalendar?storeId=" + eventCalendarClickedEvent.getStoreId()));
}
});
panel.setWidget(this.mainView.asWidget());
}
#Override
public void goTo(Place place) {
this.clientFactory.getPlaceController().goTo(place);
}
#Override
public void updateMainContent(String currentMainContentToken) {
this.mainView.updateMainContent(currentMainContentToken);
}
}
this event gets fired by MenuPresenter.clickedEventCalendar() that reacts to a click on the corresponding menu entry of the MenuView:
public class MenuPresenter implements MenuView.MenuPresenter {
// ..
#Override
public void clickedEventCalendar(Long storeId) {
this.eventBus.fireEvent(new EventCalendarClickedEvent(storeId));
}
}
One of the things I really don't like is this where I append parameters to the token e.g. to display the event calendar of a store given by storeId:
#Override
public void onEventCalendarClicked(EventCalendarClickedEvent eventCalendarClickedEvent) {
goTo(new MainPlace("eventCalendar?storeId=" + eventCalendarClickedEvent.getStoreId()));
}
is there a cleaner solution for a problem like this in GWT? I don't like the fact that I'd have to parse that string in my actual event calendar. Am I using the ActivityMapper wrong or is there simply no other way to do this?
This question should really be split into several separate ones, but that's maybe something to keep in mind for the future. If you're asking one thing then it's easier to answer thoroughly and others can find the answer easier too.
Anyway, I can see a few improvements:
use EventBinder to get rid a bit of the cruft when handling and creating new events.
if you just want to let the presenter know that a button was pressed on in the view (associated with that presenter) sending a custom event over the event bus is a bit of an overkill. Depending on your needs you can expose the button in your view's interface:
public interface Display {
HasClickHandlers getButton();
}
And then just register the ClickHandler in your presenter.
Or, if you need to do something view- and presenter- related on the click, register the ClickHandler in your view and call the presenter:
// In MainView:
#UiHandler("button")
void handleClick(ClickEvent event) {
// Do some stuff with view,
// like hide a panel or change colour
panel.setVisible(false);
// Let the presenter know that a click event has been fired
presenter.onEventCalendarClicked();
}
you're right - creating MainPlace like you are proposing is wrong. You are creating the token too soon - that's what the tokenizer associated with the place is for. You should create MainPlace by passing just the storeId to the constructor - why should MainPresenter (or any other class using this place) should know how to create the token? MainPlace should look more like this:
public class MainPlace extends Place {
private final Long storeId;
public MainPlace(Long storeId) {
this.storeId = storeId;
}
public Long getStoreId() {
return storeId;
}
public static class Tokenizer implements PlaceTokenizer<MainPlace> {
#Override
public MainPlace getPlace(String token) {
return new MainPlace(Long.valueOf(token));
}
#Override
public String getToken(MainPlace place) {
return "eventCalendar?storeId=" + place.getStoreId();
}
}
}
Now, it's the Tokenizer's responisibily to create and parse the token. Just remember to register it on your PlaceHistoryMapper.

Testing Presenters in MVP GWT application

I have a simple application and want to make it testable. I m new in this area.
Here is a simple Presenter, taking in mind this code ,could you advice or give me some example how to test it.
public class SomePresenter extends Presenter<MainPanelPresenter.Display>
{
public interface Display extends WidgetDisplay
{
HasClickHandlers getAddButton();
HasClickHandlers getDeleteButton();
void setData(ArrayList<Person> data);
ArrayList<String> getSelectedRows();
Widget asWidget();
}
private final DispatchAsync dispatcher;
public static final Place PLACE = new Place("main");
#Inject
public SomePresenter(DispatchAsync dispatcher, EventBus eventBus, Display display)
{
super(display, eventBus);
this.dispatcher = dispatcher;
bind();
}
protected void onBind()
{
display.getAddButton().addClickHandler(new ClickHandler()
{
public void onClick(ClickEvent event)
{
eventBus.fireEvent(new AddButtonEvent());
}
});
display.getDeleteButton().addClickHandler(new ClickHandler()
{
public void onClick(ClickEvent event)
{
ArrayList<String> list = display.getSelectedRows();
deletePerson(list);
}
});
}
....
private void loadDbData()
{
..........
}
private void deletePerson(ArrayList<String> ids)
{
..........
}
}
Edit:
What does the Presenter is, load initial data from db, have 2 buttons add and delete.
When add is press then a new form is load and user is able to input data and save to the db,
delete button just delete person from db.
Thanks
The general idea of unit testing such a class would be, like for any other class :
create Mock version of the dependencies (Display, EventBus, etc...)
set expectations on what the depdencies should do when the Presenter works
exercice the Presenter and check the expectations
However there are a couple of issues with your version of the Presenter :
The loadDbData() method is not showed, but I assumed it means the Presenter also has access to some other component that does the fetching. Can this component be abtracted in a dependency, and mocked liked the rest ?
Then there is the testing of bind(). The only responsibility of your Presenter in this method is to set up callbacks on some buttons provided by the Display. What you want to test is both :
That the callbacks are set
That the set callbacks do the expected things
A few ideas to help with the later :
You can reduce the coupling between Presenter and Button. If possible, change the Display interface from :
Button getAddButton();
to
addAddButtonClickedHandler(ClickHandler);
This means your Presenter does not have to use a Display object that returns actual BUtton
You can reduce the callbacks content to calling a single method, that you can then test in isolation
protected void bind() {
display.addAddButtonClickHandler(new ClickHandler() {
public void onClick(ClickEvent) {
fireAdded();
}
});
}
// The fireAdded function can be tested independenty of the Display, potentially with
// a mock EventBus
protected void fireAdded() {
event.fireEvent(....)
}
If you really want to check that the callbacks are properly set, than you can use a 'Dummy' implementation of the Display class, that provides you a list of all the callbacks, and let you call them
private class DummyDisplay implements Display {
private List<ClickHandler> addButtonClickHandlers;
public void addAddButtonClickHandler(ClickHandler handler) {
addButtonClickHandlers.add(handler);
}
public void fireAddButtonClick() {
for (ClickHandler h in addButtonClickHandlers) {
h.onClick(new ClickEvent());
}
}
// ....
}
Then your test would :
create a presenter with such a dummy display
use bind to set the callbacks
use display.fireAddButtonClick() to simulate a user clicking
check that has the result of the click, the effects of fireAdded are seen
This type of class (that mostly glue other classes together) can tend to be hard to test ; at some point, it the other classes are thoroughly tested it can become slightly counter productive to concentrate on the gluers, rather than the glued.
Hoping this helps.

GWT RootLayoutPanel - Problem rendering page from second to first (first works fine)

Sorry if this was already answered before. I did a little searching and found nothing that could solve my problem. I created an application with Spring Roo, then converted to a GWT app.
All the code generated by Spring Roo is only for CRUD. Now i want to add a Calendar for make appointments, so i need to move to another page.
I´ve added this code to
ScaffoldDesktopShell.java()
public ScaffoldDesktopShell() {
initWidget(BINDER.createAndBindUi(this));
startButton.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
RootLayoutPanel.get().add(new NovoPainel());
}
});
}
...
Then created a new UIbinder, called it NovoPainel() and added this code:
public NovoPainel() {
initWidget(uiBinder.createAndBindUi(this));
botao.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
RootLayoutPanel.get().clear();
RootLayoutPanel.get().add (new ScaffoldDesktopShell());
}
});
}
Everything goes fine moving from my root panel to NovoPainel, but when i need to go back to rootPanel the page doesn´t render correctly.
EX: Doesn´t show ** ValuePicker ** to click on left panel and render on center.
This is my RootPanel
and this image is when navigate from rootPanel to NovoPainel
and finally this one is returning from NovoPainel to RootPanel
You have to integrate with Roo generated architecture so that you can still benefit from Roo scaffolding.
Roo generated code hides most of behavior in _Roo_Gwt classes and it is because GWT doesn’t currently support ITDs. So changes have to be made in derived classes by overriding methods from _Roo_Gwt class.
To navigate application use Places, ActivityMapper and ActivitiManager (you can find good read on #Thomas Broyer posterous and GWT help).
If you take a look in ScaffoldDesktopShell.ui.xml - page is devided in three main areas.
ApplicationMasterActivities class is responsible for master area.
masterActivityManager.setDisplay(shell.getMasterPanel());
proxyListPlacePicker in ScaffoldDesktopApp.init() generates place change event with apropriate ProxyListPlace.
public void onValueChange(ValueChangeEvent<ProxyListPlace> event) {
placeController.goTo(event.getValue());
}
ApplicationMasterActivities class creates appropriate Activity in Master area by checking EntityProxy type contained in ProxyListPlace object.
public Activity getActivity(Place place) {
if (!(place instanceof ProxyListPlace)) {
return null;
}
ProxyListPlace listPlace = (ProxyListPlace) place;
return new ApplicationEntityTypesProcessor<Activity>() {
#Override
public void handlePet(PetProxy isNull) {
setResult(new PetListActivity(requests, ScaffoldApp.isMobile() ? PetMobileListView.instance() : PetListView.instance(), placeController));
}
#Override
public void handleOwner(OwnerProxy isNull) {
setResult(new OwnerListActivity(requests, ScaffoldApp.isMobile() ? OwnerMobileListView.instance() : OwnerListView.instance(), placeController));
}
}.process(listPlace.getProxyClass());
}
Navigation is created by listing all EntityProxy's in ScaffoldApp class
protected HashSet<ProxyListPlace> getTopPlaces() {
Set<Class<? extends EntityProxy>> types = ApplicationEntityTypesProcessor.getAll();
HashSet<ProxyListPlace> rtn = new HashSet<ProxyListPlace>(types.size());
for (Class<? extends EntityProxy> type : types) {
rtn.add(new ProxyListPlace(type));
}
return rtn;
}
To output meaningfull name in navigation menu they are rendered using ApplicationListPlaceRenderer
public String render(ProxyListPlace object) {
return new ApplicationEntityTypesProcessor<String>() {
#Override
public void handlePet(PetProxy isNull) {
setResult("Pets");
}
#Override
public void handleOwner(OwnerProxy isNull) {
setResult("Owners");
}
}.process(object.getProxyClass());
}
So you have to create new Activity.
public class SomeActivity extends Composite implements Activity{
private static SomeActivityUiBinder uiBinder = GWT
.create(SomeActivityUiBinder.class);
interface SomeActivityUiBinder extends UiBinder<Widget, SomeActivity> {
}
private AcceptsOneWidget display;
public SomeActivity() {
initWidget(uiBinder.createAndBindUi(this));
}
#Override
public String mayStop() {
return null;
}
#Override
public void onCancel() {
onStop();
}
#Override
public void onStop() {
this.display.setWidget(null);
}
#Override
public void start(AcceptsOneWidget panel, EventBus eventBus) {
this.display = panel;
this.display.setWidget(this);
}
}
<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
<ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder" xmlns:g="urn:import:com.google.gwt.user.client.ui">
<g:HTMLPanel>
Hello world!
</g:HTMLPanel>
</ui:UiBinder>
Create appropriate EntityProxy. It is only to obey ProxyListPlace mechanism.
public interface SomeEntityProxy extends EntityProxy {
}
Create SomeActivity in A
#Override
public Activity getActivity(Place place) {
if (!(place instanceof ProxyListPlace)) {
return null;
}
Activity activity = super.getActivity(place);
if (activity == null) {
ProxyListPlace listPlace = (ProxyListPlace) place;
if (SomeEntityProxy.class.equals(listPlace.getProxyClass())) {
activity = new SomeActivity();
}
}
return activity;
}
Add place to navigation in ScaffoldApp or override getTopPlaces in derived class.
rtn.add(new ProxyListPlace(SomeEntityProxy.class));
Set correct menu rendering text in ApplicationListPlaceRenderer
#Override
public String render(ProxyListPlace object) {
String label = super.render(object);
if(label == null) {
if (SomeEntityProxy.class.equals(object.getProxyClass())) {
label = "Some activity";
}
}
return label;
}
Code in GitHub.
GWT 2.1 introduced new classes that implements the Model-View-Places pattern (MVP). This pattern (and the GWT 2.1 concepts) are heavily based on best practices from developers who have build scalable GWT-based applications, so many people are migrating in this direction.
Roo generates a GWT 2.1 application; all of its navigational code is built on top of Activities and Places. The reason I bring this up is it sounds like you are attempting to side-step a lot of this navigational framework to implement your own. I'm not sure, but I believe your problem is coming from the fact that the MVP code is getting confused as a result.
My recommendation would be to work through the GWT MVP article linked above first. Do it completely separate of Roo, because the application that Roo generates is more complex. Once you have a good handle on it, go back through the Roo-generated application and it will likely make more sense.
You can create two div tags in your Porject.html file respectively with id firstdivtag_id1 and seconddivtag_id2.
Display first page by using
RootPanel.get("firstdivtag_id1").add(Panel1);
And then to switch over to another panel use
RootPanel.get("seconddivtag_id2").add(Panel2);

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