I need to solve a simple problem, but yet I have not been able to found out any solution yet.
I have a simple DropDownChoice with AJAX onChange() JS event. I need to add a confirm box before the onUpdate() action is done - this is not difficult, BUT I need to display the confirm box only if the new selected value of the DropDownChoice is X (one certain value), and do not display the confirm box in any other case. Is it doable?
Short example snippet:
DropDownChoice<Integer> choice = new DropDownChoice<Integer>("id", new Model<Integer>(0));
choice.add(new AjaxFormComponentUpdatingBehavior("onchange") {
#Override
protected void onUpdate(AjaxRequestTarget target) {
// do some stuff
}
#Override
protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
super.updateAjaxAttributes(attributes);
attributes.getAjaxCallListeners().add(new AjaxCallListener() {
#Override
public CharSequence getPrecondition(Component component) {
return "return confirm('Really?')"; // I NEED THIS DISPLAYED CONDITIONALLY
}
}
}
}
I don't know how to access the "choice" model object (converted input...) with the proposed value to add it to a condition in updateAjaxAttributes() method.
Thank you.
I think you should go for a JavaScript-based solution. The code of AJAX call listener is executed in a scope where you can use variable attrs. This variable contains the parameters used to perform AJAX call, including the id of the component. In this way you could check for selected value.
See more at http://wicket.apache.org/guide/guide/ajax.html#ajax_5
Related
I'm creating a CRUD application that store data in a local h2 DB. I'm pretty new to JavaFX. I've created a TabPane to with 3 Tab using an jfxml created with Scene Builder 2.0. Each Tab contains an AncorPane that wrap all the controls: Label, EditText, and more. Both the TabPane and the Tabs are managed using one controller. This function is used to create and to update the data. It's called from a grid that display all the data. A pretty basic CRUD app.
I'm stuck in the validation phase: when the user change the tab, by selecting another tab, it's called a validation method of the corresponding tab. If the validation of the Tab fails, I want that the selection remains on this tab.
To achieve this I've implemented the following ChangeListener on the SelectionModel of my TabPane:
boolean processingTabValidationOnChange = false;
tabPane.getSelectionModel().selectedIndexProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> ov, Number t, Number t1) {
if (processingTabValidationOnChange == false) {
boolean success;
switch (t.intValue()) {
case 0: success = validationTab1Passed();
break;
case 1: success = validationTab2Passed();
break;
case 1: success = validationTab3Passed();
break;
default: success = false;
}
if (success == false) {
processingTabValidationOnChange = true;
// select the previous tab
tabPane.getSelectionModel().select(t.intValue());
processingTabValidationOnChange = false;
}
}
}
});
I'm not sure that this is the right approach because:
The event changed is fired two times, one for the user selection and one for the .select(t.intValue()). To avoid this I've used a global field boolean processingTabValidationOnChange... pretty dirty I know.
After the .select(t.intValue()) the TabPane displays the correctly Tab as selected but the content of the tab is empty as if the AnchorPane was hidden. I cannot select again the tab that contains the errors because it's already selected.
Any help would be appreciated.
Elvis
I would approach this very differently. Instead of waiting for the user to select a different tab, and reverting if the contents of the current tab are invalid, prevent the user from changing tabs in the first place.
The Tab class has a disableProperty. If it is set to true, the tab cannot be selected.
Define a BooleanProperty or BooleanBinding representing whether or not the data in the first tab is invalid. You can create such bindings based on the state of the controls in the tab. Then bind the second tab's disableProperty to it. That way the second tab automatically becomes disabled or enabled as the data in the first tab becomes valid or invalid.
You can extend this to as many tabs as you need, binding their properties as the logic dictates.
Here's a simple example.
Update: The example linked above is a bit less simple now. It will dynamically change the colors of the text fields depending on whether the field is valid or not, with validation rules defined by bindings in the controller. Additionally, there are titled panes at the top of each page, with a title showing the number of validation errors on the page, and a list of messages when the titled pane is expanded. All this is dynamically bound to the values in the controls, so it gives constant, clear, yet unobtrusive feedback to the user.
As I commented to the James's answer, I was looking for a clean solution to the approach that I've asked. In short, to prevent the user to change to a different tab when the validation of the current tab fails. I proposed a solution implementing the ChangeListener but, as I explained: it's not very "clean" and (small detail) it doesn't work!
Ok, the problem was that the code used to switch back the previous tab:
tabPane.getSelectionModel().select(t.intValue());
is called before the process of switching of the tab itself it's completed, so it ends up selected... but hidden.
To prevent this I've used Platform.runLater(). The code .select() is executed after the change of tab. The full code becomes:
//global field, to prevent validation on .select(t.intValue());
boolean skipValidationOnTabChange = false;
tabPane.getSelectionModel().selectedIndexProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> ov, Number t, Number t1) {
if (skipValidationOnTabChange == false) {
boolean success;
switch (t.intValue()) {
case 0:
success = validationTab1Passed();
break;
case 1:
success = validationTab2Passed();
break;
case 1:
success = validationTab3Passed();
break;
default:
success = false;
}
if (success == false) {
Platform.runLater(new Runnable() {
#Override
public void run() {
skipValidationOnTabChange = true;
tabPane.getSelectionModel().select(t.intValue());
skipValidationOnTabChange = false;
}
});
}
}
}
});
Anyway, if anyone has a better solution to accomplish this, you're welcome. In example using a method like consume() to prevent the tab to be selected two times. This way I can eliminated the global field skipValidationOnTabChange.
Elvis
I needed to achieve the similar thing. I've done this by changing the com.sun.javafx.scene.control.behavior.TabPaneBehaviour class by overriding selectTab method:
class ValidatingTabPaneBehavior extends TabPaneBehavior {
//constructors etc...
#Override
public void selectTab(Tab tab) {
try {
Tab current = getControl().getSelectionModel().getSelectedItem();
if (current instanceof ValidatingTab) {
((ValidatingTab) current).validate();
}
//this is the method we want to prevent from running in case of error in validation
super.selectTab(tab);
}catch (ValidationException ex) {
//show alert or do nothing tab won't be changed
}
}
});
The ValidatingTab is my own extension to Tab:
public class ValidatingTab extends Tab {
public void validate() throws ValidationException {
//validation
}
}
This is the "clean part" of the trick. Now we need to place ValidatingTabPaneBehavior into TabPane.
First you need to copy (!) the whole com.sun.javafx.scene.control.skin.TabPaneSkin to the new class in order to change its constructor. It is quite long class, so here is only the part when I switch the Behavior class:
public class ValidationTabPaneSkin extends BehaviorSkinBase<TabPane, TabPaneBehavior> {
//copied private fields
public ValidationTabPaneSkin(TabPane tabPane) {
super(tabPane, new ValidationTabPaneBehavior(tabPane));
//the rest of the copied constructor
}
The last thing is to change the skin in your tabPane instance:
tabPane.setSkin(new ValidationTabPaneSkin(tabPane));
I need to recreate new page instance on every page load (also when user pressed Back button).
So I overrided OnBackKeyPress method:
protected override void OnBackKeyPress(CancelEventArgs e)
{
base.OnBackKeyPress(e);
if (NavigationService.CanGoBack) {
e.Cancel = true;
var j = NavigationService.RemoveBackEntry();
NavigationService.Navigate(j.Source);
NavigationService.RemoveBackEntry();
}
}
The problem is that I can't handle case when user press back button to close CustomMessageBox dialog. How can I check it? Or is there any way to force recreation of page instance when going back through history state?
Why do you need to recreate the page instance? If you are simply trying to re-read the data to be displayed, why not put the data loading logic into OnNavigatedTo()?
Assuming that is what you are actually trying to achieve, try something like this...
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
// don't do your data loading here. This will only be called on page creation.
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
LoadData();
base.OnNavigatedTo(e);
}
MyViewModel model;
async void LoadData()
{
model = new MyViewModel();
await model.LoadDataAsync();
}
}
If you also have specific logic that you need to run on first construction of the page vs. on a back key navigation, check the NavigationMode property of the NavigationEventArgs object that gets passed to OnNavigatedTo.
if(e.NavigationMode == NavigationMode.New)
{
//do what you need to do specifically for a new page instance
}
if (e.NavigationMode == NavigationMode.Back)
{
// do anything specific for back navigation here.
}
Ha, in the near thread, i have opposite question :)
What about MessageBox - it depends, which one are you using. It can be custom message box, for example. Anyway, try to check MessageBox.IsOpened (or alternative for your MessageBox) in your OnBackKeyPress().
Another solution is to use OnNavigatedTo() of the page you want to be new each time.
Third solution: in case you works with Mvvm Light, add some unique id in ViewModel getter, like
public MyViewModel MyViewModel
{
get
{
return ServiceLocator.Current.GetInstance<MyViewModel>((++Uid).ToString());
}
}
This would force to recreate new ViewModel each time, so you'd have different instance of VM, so you would have another data on the View.
I have a list of items that goes to another page, That page is hooked up to a view model. In the constructor of this view model I have code that grabs data from the server for that particular item.
What I found is that when I hit the back button and choose another item fromt hat list and it goes to the other page the constructor does not get hit.
I think it is because the VM is now created and thinks it does not need a new one. I am wondering how do I force a cleanup so that a fresh one is always grabbed when I select from my list?
I faced the same issue, that's how i solved it.
Have a BaseView class, override OnNavigatedTo
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
if (NavigatedToCommand != null && NavigatedToCommand.CanExecute(null))
NavigatedToCommand.Execute(null);
}
add DependencyProperty.
public static readonly DependencyProperty NavigatedToCommandProperty =
DependencyProperty.Register("NavigatedToCommand", typeof(ICommand), typeof(BaseView), null);
public ICommand NavigatedToCommand
{
get { return (ICommand)GetValue(NavigatedToCommandProperty); }
set { SetValue(NavigatedToCommandProperty, value); }
}
On the necessary pages, add to xaml (and, of course, inherit BaseView )
NavigatedToCommand="{Binding OnNavigatedToCommand}"
In the ViewModel, make command itself
public RelayCommand OnNavigatedToCommand
{ get { return new RelayCommand(OnNavigatedTo); } }
and implement method you want to call to update list
public async void OnNavigatedTo()
{
var result = await myDataService.UpdateMyList();
if (result.Status == OK)
MyList = result.List;
}
So, now, every time you navigate to page with list, inside of overriden OnNavigatedTo(), a NavigatedToCommand would be executed, which would execute OnNavigatedToCommand (which you set in xaml), which would call OnNavigatedTo, which would update your list.
A bit messy, but MVVM :)
EDIT: What about cleanings, they can be done in OnNavigatedFrom(), which works the same. Or OnNavigatingFrom(), which also can be useful in some cases.
I use codenameone to develop my mobile application. In this application I implement some classes and codes manually for instance create all forms by hard coding not using codenameone designer for some reason.
By the way I wanted to navigate in forms like what codenameone use, so I use one variable from type of Form called it prevForm and when I want to open a form I set it to current form and then I show new form.
Ok, that is main scenario. In this application I wanna implement internationalization too, so I create my own hashtable (Farsi and English) for this application.
This is my problem:
How can I set or change language and apply it to forms that I opened?
Is my method for navigate between forms are good?
Here is my code:
public class BaseForm extends Form implements ActionListener {
public BaseForm(){
this.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
}
Command exit, ok, back;
Form prevForm;
protected void initForm(){
}
protected void showForm(){
}
protected void showForm(final Form prevForm){
//String name = this.getName();
//if("Reminder".equals(name) || "3Transaction".equals(name))
{
this.prevForm = prevForm;
Form f = this;
back = new Command("Back");
//ok = new Command("Ok");
//delete = new Command("Delete");;
Button button = new Button("Button");
f.addCommand(back);
//f.addCommand(ok);
//f.addCommand(delete);
//f.addComponent(button);
f.addCommandListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
if (ae.getCommand().equals(back)) {
//Do Exit command code
System.out.println("Back pressed");
prevForm.showBack();
} else if (ae.getCommand().equals(ok)) {
//Do Start command code
System.out.println("Ok pressed");
}
}
});
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
//Do button code
System.out.println("Action performed");
}
});
}
showForm();
}}
for open nested form I use this code:
LanguageUI lang = new LanguageUI();
lang.showForm(this);
change language [form]:
protected boolean onBtnSave() {
if(isRbFarsiSelected()){
UIManager.getInstance().setResourceBundle(new CommonSettings().getFarsi());
}
else {
UIManager.getInstance().setResourceBundle(new CommonSettings().getEnglish());
}
return false;
}
I also hard code my UI on lwuit, and i have a variable parentForm on every class so i can easily show previous form. For language change i know there is Localization in the resource editor that you can make use of. Below is how you can access it. I guess the trick is how to set the content of the L10N in the res file in code? On the other hand you can create your own helper classes that mirror the methods below.
Resources theme = Resources.open("/theme.res");
theme.getL10N(id, locale);
theme.getL10NResourceNames();
theme.isL10N(name);
theme.listL10NLocales(id)
I need to set the ENTER key to navigate between enabled fields placed on a com.vaadin.ui.Panel. How can i programmatically do this?
This is my intent but doesn't now how to send a keypress:
Action ENTER_KEY_ACTION = new ShortcutAction(
"Enter key"
, ShortcutAction.KeyCode.ENTER
, null
);
public Action[] getActions(Object target, Object sender) {
return new Action[] { ENTER_KEY_ACTION};
}
public void handleAction(Action action, Object sender, Object target) {
if (action == ENTER_KEY_ACTION ) {
ENTERKeyHandler();
}
}
protected void ENTERKeyHandler(){
//
//here i need to send a TAB keyPress
//
}
this code work perfectly up to now but isn't ended. I don't know if there is another way to accomplish this?
please sorry my English too.
The AbstractComponent class provides a method for this (Your field object extends AbstractComponent). The method is called fireEvent(Component.Event event).
You could try to send an event to the registered listeners with this approach.
Try to add a FocusListener to your fields in the Panel, which keeps track of the currently focused field. You also have to know the tabbing order of the fields on the server-side and in the ENTERKeyHandler() method you call field.focus() for the field to be focused.