Flex Spark tabbar : initialize hidden tabs - apache-flex

problem is I have a spark Tabbar, with many forms in each tab.
But I have a single global save button. Problem is, if I don't open a Tab,
it doesn't get initialized and therefore the forms it contains do not exist..
How Can I make it as if the user had clicked on every tab?

The best way to handle this is to have a data model that each tab is displaying and editing, rather than trying to go in and read the values out of the controls in each tab, and save those. This is at the heart of MVC.
However, if you're too invested in your current architecture to be able to change it and you are using a ViewStack with your TabBar, you may find that setting creationPolicy to "all" does what you want. If you're using States, I don't think you can force all of them to be instantiated without putting your application into each State at least once.

Related

Show alert if moving on without saving in Flex?

Functionnaly :
On one of my components of my application, I have an editing/lock system. When a user starts editing, he locks the file so other users cannot edit it.
Problem scenario : When the user activates "edition mode" and leaves screen, I would like to show a alert with two options : save changes, or discard changes.
There are different ways to exit screen :
There is a List on the left side containing other possible editabel data. A click changes the data in my component.
There is a menubar on top leading to other screens.
The edition component is embedded in a Tab navigator. When changing tabs, the alert has to show.
Closing browser.
Do I have to catch all of these events and plug at all those places?
Is there any kind of focusout mecanism?
The answer to the first question is: YES.
You need to watch all possible exit events that could harm the currently edited data.
Well, the problem is now how to manage this properly. Using an MVC framework you would trigger the appropriate commands from your components:
CHANGE_LIST_ITEM (new item)
CHANGE_TAB (new tab)
CHANGE_SCREEN (new screen)
Each command then checks if the currently edited tab has been saved or not. If not, it displays the Alert. Else, if there are no changes, it allows the list, the screen chooser and the tab bar to continue.
So your components (list, screens, tabs) need to implement some kind of rollback or preventDefault mechanism. Generally, changing their state must be allowed by a central validator (in MVC the command).
In the case of the list: I would suggest that the list is not selectable by mouse click but only programmatically. You set a listener on the list item click event. If the command allows setting of a new item it will notify the list. In MVC usually by sending an async message that gets received by the list's mediator. [[And even more correct: The command would set some model properties (e.g. currentListItem) and the model than sends an async message.]]
Edit: For the browser close event, you need to call a JavaScript expert.

Flex custom component first item not read by JAWS

Flex application is being made accessibility compliant. When a custom component is made visible based on some condition, the first item (either text or formitem or textarea) inside the component is skipped by Jaws. It reads from the second item. On pressing UP arrow, the first item is then read.
Is there a way to make the first item accessible without need for pressing UP arrow?
This is likely going to be related to focus management.
You're likely going to want to assign componentId.setFocus() to the first component in the current view when the view state changes.
You need to re-assess the focus when the state of your display changes. If you post how you are managing display state I can suggest exactly how to trigger that via an event or in your custom state method.
Also, if that doesn't work, try this once your screen is ready / state changed :
focusManager.moveFocus(mx.events.FocusRequestDirection.TOP);

Straightforward way to count number of windows up through PopUpManager?

I'm using the PopUpManager to bring a bunch of event windows up.
I want to make it so that only one window can be open at a time, but I don't see anywhere in the code that tracks open windows to set up a conditional. I guess it just creates the windows and then sets them free?
Thinking about a windowCount variable that increments when I add a window and decrements when I remove one, but since the PopupManager is called in different classes I'd have to start throwing events all over the place. I can do that, but I'm wondering if there's a more straightforward method?
The systemManager (rather than PopUpManager, go figure...) provides information on the currently opened popup windows.
If your popups are all model then you will be interested in 'systemManager.numModalWindows':
The number of modal windows. Modal
windows don't allow clicking in
another windows which would normally
activate the FocusManager in that
window. The PopUpManager modifies this
count as it creates and destroys modal
windows.
Otherwise try out 'systemManager.popUpChildren':
An list of the topMost (popup) windows
being parented by this ISystemManager.
An ISystemManager has various types of
children, such as the Application,
popups, tooltips, and custom cursors.
You can access the top-most windows
through the popUpChildren property.
The IChildList object has methods like
getChildAt() and properties like
numChildren. For example,
popUpChildren.numChildren gives the
number of topmost windows and you can
access them as
popUpChildren.getChildAt(i).
I see a few options:
1) Make all your windows modal; so that the application can't be used until the window is closed. This is a argument to the createPopUp method on the PopUpManager. Presumably you do not have Popups creating other popups.
2) Create your own Manager class, possibly an extension of the PopUpManager class that keeps track of all open windows. Then you'd have a single source of all PopUps and could maintain them that way.

Flex 3 - Force all controls to render at start

When I try to access the hidden TABs of my tab navigator control in action script, it returns a null error. But it works OK if I just activate the control in the user interface once. Obviously the control is not created until I use it. How do I make all the tabs automatically created by default ?
<mx:TabNavigator creationPolicy="all"/>
That should do it. Deferred instanciation is a feature, but sometimes it is a hassle.
The Flex framework is optimizing creation be default (creationPolicy="auto") so if you have a configuration dialog with a lot of tabs, for example, and the most useful tab is the first one, your application does not spend time and memory initializing the tabs that the user never sees.
This makes a lot of difference when dialogs like this never release, and is a good default to go with.
One thing to look at is using a private variable in your dialog/form instead of pushing the data to the control on the hidden page. This style treats the whole form as if it were a component, which it sort of is. To repeat: the MXML form/dialog/canvas is a class, and it can have data and methods in addition to containing other components.
Cheers
On a side note, I've run into the deferred-loading policy in a multi-state application, and circumvented it by forcing all elements to be included and invisible in the initial state. Something to consider, but only as a hack.

How can I disable an individual item in a combo box in Flex so that it is not clickable?

I want to create a combobox in flex which will take three values, Available, Unavailable, and Busy. The constraint is, I should not allow user to go directly from Unavailable to Busy. So when a User is selected Unavailable, I should keep the Busy item disabled (unselectable), but a user will be able to go directly from Available to Busy. I chouldn't find a straight forward way to disable an item in combobox in Flex. How can I do that?
Have you considered using radio buttons rather than a combo box? It's clear how to do this for radio buttons, for one thing. Also, it can often be friendlier to present the available options without requiring a click to reveal them. (Especially if, as in this case, you are adding the possibility that an option is "available, but not possible for you right now for some reason not shown in this combo-box item").
If you really want a combo-box, you can use the click event to display it in a non-standard fashion by probably changing its style; and then, if clicked anyway, Then, in the selected event, reject the choice (hopefully with an indication of why),
Or, if you want to simply remove it from the list, you can have the click listener event repopulate the source list each time, based on conditions. But that might be confusing to the user, too.
You can also have a look at
www.stoimen.com/blog/2009/03/05/flex-3-combobox-disabled-options/
which references
wmcai.blog.163.com/blog/static/4802420088945053961/
(note for NoScript users you must have 163.com and 126.com at least temporarily allowed to be
able to properly see this page)
it works very well even though I added the code for being able to properly handle keyboard
events in the dropdown list
Full self working example available at
http://olivierbourdon.homedns.org/OpenSource/combos.zip
Thanks again for the good work

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