I wrote a code to run a method when a date selected from DatePicker in JavaFX. But my event code runs on second date selection and I don't understand why this occurs.
My code is like this:
public void handleDateSelectEvent(){
appointmentDay.setOnAction(event -> {
System.out.println("Tarih Seçildi:"+appointmentDay.getValue());
java.util.Date selectedDate= java.sql.Date.valueOf(appointmentDay.getValue());
List<String> avaliableClocks = new ArrayList<String>();
for (AppointmentClocks ac : findAppointmentClocks(selectedDate)){
avaliableClocks.add(ac.getClock());
}
ObservableList obClocks = FXCollections.observableList(avaliableClocks);
appointmentClock.getItems().clear();
appointmentClock.setItems(obClocks);
});
}
You're probably using handleDateSelectEvent() as handler of the onAction event inside a fxml file. The handler should contain the handling code directly instead of registering the event handler:
public void handleDateSelectEvent(){
System.out.println("Tarih Seçildi:"+appointmentDay.getValue());
java.util.Date selectedDate= java.sql.Date.valueOf(appointmentDay.getValue());
List<String> avaliableClocks = new ArrayList<String>();
for (AppointmentClocks ac : findAppointmentClocks(selectedDate)){
avaliableClocks.add(ac.getClock());
}
ObservableList obClocks = FXCollections.observableList(avaliableClocks);
appointmentClock.getItems().clear();
appointmentClock.setItems(obClocks);
}
Related
I have some property which I am using from Page2 in HomePageViewModel, When I navigate to Page2 I have changed that property and on coming back by doing NavigiationPop.
HomePage is not re-loaded/ refreshed at all as I have set the BindingContext in the constructor of HomePage, which is loaded only once.
The solution which is working for me is
Setting the BindingContext to the ViewModel on "onAppearing()", usually its not consider the best practice. But I also need to refresh the values which I have changed on Page2.
Looking forward for your valuable inputs and suggestions.
Also Pros/Cons of Setting the BindingContext in OnAppearing.
Thanks,
Hemant
It depends on you, they all can achieve the effect.
However if you want to reduce the CPU consumption of the program, then don't use the onAppearing method too much to refresh the page data.
Another method is that you can change the data of the model through Delegate/Event/MessageCenter.
You can refer to this discussion to know how to use Delegate/Event/MessageCenter.
Here I will give the sample by using MessageCenter to achieve that.
For example, the TestViewModel as follows:
public class TestViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
private string pagetitle;
public string PageTitle
{
get
{
return pagetitle;
}
set
{
if (pagetitle != value)
{
pagetitle = value;
NotifyPropertyChanged();
}
}
}
}
Then bind it in FirstPage as follows, and Subscribe MessageCenter inside it:
TestViewModel testViewModel = new TestViewModel();
BindingContext = testViewModel;
MessagingCenter.Subscribe<object>(this, "Hi", (sender) =>
{
// Do something whenever the "Hi" message is received
testViewModel.PageTitle = "Modified Title";
});
Then in the SecondPage, when changing the data by sending message. When back to FirstPage, the View Will be updated.
private void Button_Clicked(object sender, EventArgs e)
{
MessagingCenter.Send<object>(this, "Hi");
}
I have a CalendarView that looks like this:
<CalendarView
android:layout_width="match_parent"
android:layout_height="300dp"
android:id="#+id/createReservationCalendarView" />
Here is how I handle the DateChange event without MvvmCross:
protected override void OnCreate(Bundle savedInstanceState)
{
... Code ...
calendar.DateChange += (s, args) =>
{
var year = args.Year;
var month = args.Month + 1;
var dayOfMont = args.DayOfMonth;
var date = new DateTime(year, month, dayOfMont);
var myReservations = new Intent(this, typeof(CreateReservationTimeslotScreen));
myReservations.PutExtra("selectedDate", date.Ticks);
StartActivity(myReservations);
};
}
Now that I have switched to MvvmCross, I would like to have my ViewModel start the new activity instead.
Im not sure how to do this, since the ViewModel should be OS and UI agnostic.
The "args" argument is of type CalendarView.DateChangeEventArgs, which is Android specific, so I cant use that in the ViewModel. It derives from System.EventArgs, so maybe I could use that instead. I am thinking that there must be a simpler way.
A thought that I had was if it is possible to update a property on the ViewModel from the activity, and then execute the switch to the new Activity from there? I'm not sure how this could be accomplished since activites dont have references to their ViewModels.
Any suggestions?
Thanks.
MvvmCross does give you access to your ViewModel from your View. The relationship between your View (e.g. Activity/fragment in Android) and your ViewModel, and their ability to share data (models) in both directions is a core characteristic a Mvvm framework.
In order to setup an Activity to be used with MvvmCross you need to make sure to inherit from MvxActivity or MvxAppCompatActivity (If using Android Support Library). Following which you need to link your Activity to its corresponding ViewModel using one of the possible conventions (See link, for basic sample of each registration offered by the MvxViewModelViewTypeFinder). A simple example would be to use the concrete type based registration using the type parameter overload.
public class FirstActivity : MvxAppCompatActivity<FirstViewModel>
Now that you have access to your ViewModel from your View you can create a command that can be used to execute the navigation:
CalendarViewModel (ViewModel linked to the current Activity in question)
Create a command that requires a DateTime parameter, which in turn will pass the value when navigation (see MvvmCross Navigation docs for alternative navigation and parameter passing conventions).
public class CalendarViewModel : MvxViewModel
{
IMvxCommand _goToMyReservationCommand;
public IMvxCommand GoToMyReservationCommand =>
_goToMyReservationCommand ??
(_goToMyReservationCommand = new MvxCommand<DateTime>(NavigateToMyReservation));
void NavigateToMyReservation(DateTime reservationDate)
{
ShowViewModel<MyReservationViewModel>(
new GoToMyReservationParameter
{
ReservationTicks = reservationDate.Ticks
});
}
}
Navigation Parameter Class
Holds the values and type information used for navigation.
public class GoToMyReservationParameter
{
public long ReservationTicks { get; set; }
}
MyReservationViewModel
The ViewModel that will receive the value passed.
public class MyReservationViewModel : MvxViewModel
{
public void Init(GoToMyReservationParameter parameters)
{
var reservationTicks = parameters.ReservationTicks;
// Do what you need with the parameters
}
}
View
Execute the command on the ViewModel and pass through the DateTime object.
public class CalendarActivity : MvxAppCompatActivity<CalendarViewModel>
{
protected override void OnCreate(Bundle bundle)
{
... Code...
calendar.DateChange += (s, args) =>
{
var year = args.Year;
var month = args.Month + 1;
var dayOfMont = args.DayOfMonth;
var date = new DateTime(year, month, dayOfMont);
ViewModel.GoToMyReservationCommand.Execute(date);
};
}
}
I have an MVC application in which I have to update the view with the current value of a stream.
In the model I have this method:
public Observable<Integer> getStreamInstance(){
if(stream == null){
this.stream = Observable.create((Subscriber<? super Integer> subscriber) -> {
new HeartbeatStream(frequence,subscriber).start();
});
}
return stream;
}
which I use in the controller to get the stream. Then, in the controller I have these two methods:
public void start(){
this.sb = stream.subscribe((Integer v) -> {
view.updateCurrValue(v);
});
}
public void stop(){
this.sb.unsubscribe();
}
With the start method I simply update a label in the view with the current value.
This works fine until I try to stop the updating with the unsubscribing; infact, when I press the button "stop" in the view, the label keeps updating with the current value and, if I press "start" again, the label shows the values from two different streams, the one that I first created with the first "start" and the second that seems has been created with the second pressing of "start".
Where am I wrong?
EDIT:
public class HeartbeatStream extends Thread{
private Subscriber<? super Integer> subscriber;
private int frequence;
private HeartbeatSensor sensor;
public HeartbeatStream(int freq, Subscriber<? super Integer> subscriber){
this.frequence = freq;
this.subscriber = subscriber;
sensor = new HeartbeatSensor();
}
public void run(){
while(true){
try {
subscriber.onNext(sensor.getCurrentValue());
Thread.sleep(frequence);
} catch (Exception e) {
subscriber.onError(e);
}
}
}
This is the HeartbeatStream class. HeartbeatSensor is a class that periodically generates a value that simulates the heartbeat frequence.
I'm guessing you tried to periodically signal some event that triggers the screen update. There is an operator for that:
Observable<Long> timer = Observable.interval(period, TimeUnit.MILLISECONDS,
AndroidSchedulers.mainThread());
SerialSubscription serial = new SerialSubscription();
public void start() {
serial.set(timer.subscribe(v -> view.updateCurrValue(v)));
}
public void stop() {
serial.set(Subscriptions.unsubscribed());
}
public void onDestroy() {
serial.unsubscribe();
}
Observable by design unsubscribe your observer once that all items are emitted and onComplete callback is invoked.
Look this example https://github.com/politrons/reactive/blob/master/src/test/java/rx/observables/creating/ObservableSubscription.java
I guess you're not handling the unsubscribe - although I can't see what's going on in your HeartbeatStream class.
If you're creating an Observable with Observable.create then you need to handle unsubscribing explicitly with subscriber.isUnsubscribed().
Where possible use some of the utility methods to create an Observable - they handle this all for you eg Observable.just() or Observable.from().
If this doesn't help, please post your HeartbeatStream class.
See the the docs for more details:
https://github.com/ReactiveX/RxJava/wiki/Creating-Observables
https://github.com/ReactiveX/RxJava/wiki/Async-Operators
I have a java class:
public Task {
private int id;
private Company sender;
private Company receiver;
//Getter and Setter
...
}
As you can see, I have 2 other custom classes in the task class. And a company has for example Adress and Directory.
I have a CompanyPanel which will reusable be used on the Page. Here is some code from the panel.
public class CompanyPanel extends Panel {
protected List<Company> companies;
public CompanyPanel(String id, IModel<Company> model) {
super(id,new CompoundPropertyModel<Company>(model));
companies = new ArrayList<Company>();
Company company_1 = new Company();
//Setting default predefined values for the company, so I can select it from the dropdown and to set fields automatically
company_1.setFtpAdress("adress1.com");
company_1.setFtpDir("/MusterDir/");
companies.add(company_1);
//SAME for another company
...
companies.add(comany_2);
...
final DropDownChoice<Company> companyList = new DropDownChoice<Company>("companies", model,
new LoadableDetachableModel<List<Company>>() {
#Override
protected List<Company> load() {
return companies;
}
}){
protected boolean wantOnSelectionChangedNotifications() {
return true;
}
};
add(companyList);
final TextField<String> ftpAdress = new TextField<String>("ftpAdress");
ftpAdress.setOutputMarkupId(true);
add(ftpAdress);
final TextField<String> ftpDir = new TextField<String>("ftpDir");
ftpDir.setOutputMarkupId(true);
add(ftpDir);
//added Ajax to dropdown to update textfields automatically, based on selection of dropdown
companyList.add(new AjaxFormComponentUpdatingBehavior("onchange")
{
#Override
protected void onUpdate(AjaxRequestTarget target)
{
target.add(ftpAdress);
target.add(ftpDir);
}
});
}
}
In the Page I use reuseable CompanyPanels.
...
CompanyPanel senderPanel = new CompanyPanel("senderPanel", new PropertyModel(task,"sender"));
senderPanel.setOutputMarkupId(true);
form.add(senderPanel);
CompanyPanel receiverPanel = new CompanyPanel("receiverPanel", new PropertyModel(task,"receiver"));
receiverPanel.setOutputMarkupId(true);
form.add(receiverPanel);
...
When I submit the form I do:
public void onSubmit(AjaxRequestTarget target, Form<?> form) {
//doSomething
target.add(senderPanel);
target.add(receiverPanel);
}
The problem: The company panel is not being rerendered. And I don't really know why.
Workflow:
I select a company from the dropdown panel
The TextFields(which are inside the companyPanel) will be set correctly, based on the dropdown
I modify a textField (which belongs to a company)
I submit the form
I change the company from the dropdown list
I change back to the first company -> PROBLEM: the modified textfields displays still the modified text inside. It was not reseted to the default values.
Any help very appreciated.
Of course they will display the modified values. You create a list of companies in the CompanyPanel constructor. When you modify a company's data, the object is modified inside that list.
A quick way to fix this would be to replace the CompanyPanel panel with a new instance of CompanyPanel in your onSubmit method. That would recreate the list of companies with your default values. You would of course lose the modified values.
Another possibly better fix is to move the companies list creation into the loadabledetachablemodel:
final DropDownChoice<Company> companyList = new DropDownChoice<Company>("companies", model,
new LoadableDetachableModel<List<Company>>() {
#Override
protected List<Company> load() {
List<Company>companies = new ArrayList<Company>();
Company company_1 = new Company();
//Setting default predefined values for the company, so I can select it from the dropdown and to set fields automatically
company_1.setFtpAdress("adress1.com");
company_1.setFtpDir("/MusterDir/");
companies.add(company_1);
//SAME for another company
...
companies.add(comany_2);
...
return companies;
}
This way the list of companies is recreated on every request with the default values.
Make sure you implement a proper equals() and hashCode() method in Company though for DropDownChoice to show the proper selected element though - because in this scenario the object in your model and the objects in the list may never be ==.
You have to provide more code. If you submit the correctly so that the model changes try:
senderPanel.modelChanged();
receiverPanel.modelChanged();
target.add(senderPanel);
target.add(receiverPanel);
I'm using wicket version 6.
I have a form. as contents of the form, I have a FormComponentPanel that contains two DateTimeField's (org.apache.wicket.extensions.yui.calendar).
In the class containing the form I have one AjaxButton, and one AjaxLink, both doing the same: reading the models, creating a new object and sending it to some server for processing.
Anyhow,
when clicking on the Link my new object is created with the correct values except those newly dates selected with the datepicker
when clicking the Button I get some error ([AjaxRequestHandler#1701777932 responseObject [org.apache.wicket.ajax.AjaxRequestHandler$1#3e1]) but no further information on the error
well, I addressed the first issue (Link) with trying to add ajax update behavior to it, as suggested here , but the selected date is not updated in the model
the AjaxButton is created and onSubmit overwritten with just calling another method and target.add(form); also setOutputMarkupId is set to true, but it seems that still something is missing
In order to get it to work I'd just need to solve one of the problems, but it would be great if someone has a solution for both problems. Thanks in advance.
edit
public MyPanelIncludingForm() {
// ...
form.add(getRangePanel()); // creates a new TimeRangePanel and returns the instance
form.add(getSubmitButton());
// ...
}
private FormComponent<String> getSubmitButton() {
FormComponent<String> submitBtn = new AjaxButton("submitBtn", form) {
private static final long serialVersionUID = 3005L;
#Override
protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
System.out.println("submit QT ajax button");
setResponsePage(HomePage.class);
sendQuery();
target.add(form);
}
#Override
protected void onError(AjaxRequestTarget target, Form<?> form) {
System.err.println("error occurred. " + target);
target.add(feedback);
}
};
submitBtn.setOutputMarkupId(true);
return submitBtn;
}
// separate FormComponentModel for timeRange
public class TimeRangePanel extends FormComponentPanel<MyRange> {
MyRange range;
PropertyModel<Date> dpFromPM = new PropertyModel<Date>(this, "range.start");
PropertyModel<Date> dpToPM = new PropertyModel<Date>(this, "range.stop");
public RangePanel(String id, IModel<MyRange> model) {
super(id, model);
dpFrom = new DateTimeField("dpFrom", dpFromPM) {
private static final long serialVersionUID = 3006L;
#Override
protected DateTextField newDateTextField(String id, PropertyModel<Date> model) {
DateTextField dtf = super.newDateTextField(id, model);
AjaxFormComponentUpdatingBehavior a = new AjaxFormComponentUpdatingBehavior("onChange") {
private static final long serialVersionUID = 3006L;
#Override
protected void onUpdate(AjaxRequestTarget target) {
System.out.println("here u " + dpFrom.getModelObject().toString());
}
};
dtf.add(a);
return dtf;
}
};
// second DateTimeField as dpFrom
} // end of constructor
#Override
protected void onBeforeRender() {
range = getModelObject();
super.onBeforeRender();
}
} // end of class
edit2
this is what the wicket ajax debug window is printing:
INFO: focus removed from
INFO: focus set on submitBtn11
INFO: Received ajax response (299 characters)
INFO:
<div wicket:id="feedbackQuery" class="feedback" id="feedbackQuery1c"><wicket:panel>
<ul wicket:id="feedbackul" class="feedbackPanel">
<li wicket:id="messages" class="feedbackPanelERROR">
<span wicket:id="message" class="feedbackPanelERROR"></span>
</li>
</ul>
</wicket:panel></div>
INFO: returned focused element: [object HTMLInputElement]
INFO: returned focused element: [object HTMLInputElement]
INFO: Response processed successfully.
INFO: refocus last focused component not needed/allowed
INFO: focus removed from submitBtn11
edit3
As I wrote in a comment:
I removed the re-usable components (FormComponentPanel) and now I don't get an error with the AjaxButton . anyhow, it's weird, I thought re-usable components should work, even with Ajax; also the models were assigned properly.
when clicking the Button I get some error
([AjaxRequestHandler#1701777932 responseObject
[org.apache.wicket.ajax.AjaxRequestHandler$1#3e1]) but no further
information on the error
=> You should run Wicket in DEVELOPMENT mode to get a more detailed trace.
You might simply add in your form a field called:
range.start
range.stop
and use the Object MyRange as property model instead create a new one for each field.
There is actually no need for that extra cycle. And I don't think Wicket will write the information back to the MyRange object if you create new PropertyModels for every attribute.
For example: http://svn.apache.org/viewvc/incubator/openmeetings/trunk/singlewebapp/src/org/apache/openmeetings/web/components/admin/users/UserForm.java?view=markup
Line 276
and the corresponding HTML
http://svn.apache.org/viewvc/incubator/openmeetings/trunk/singlewebapp/src/org/apache/openmeetings/web/components/admin/users/UsersPanel.html?view=markup
Line 82
Sebastian