I am trying to develop a mobile application using flex. Whenever I use 'navigator.popView()' to go back to the last view that was shown, it loads a new view on to the screen, instead of using the old one itself.
On the first screen, I have a TextInput into which I enter some text, when I push next and then push back the TextInput is empty. I want to retain the text in the TextInput.
It is advisable not to keep views in memory by default, so discarding old views and creating new ones is really the desired behavior. You should bind the content of your TextInput to a variable and store and retrieve only its text value.
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I am new in Xamarin forms and I need to implement a table in Xamarin forms. Requirement is-
Initially table will be empty and has four columns. After feeling form and clicking on submit button, new entry will be added in table. First column is Test, second column is single radio button, third column is again single radio button and forth column is button to delete that row it self.
I need to know which approach will be suitable to implement this requirement. Is it grid layout or tableview or something else.
Consider Table View use cases vs List View use cases. Table views are meant for static content. You should really consider a list view for dynamic content. (like adding a row with views) Being new to Xamarin.Forms, you should take the time to read completely through the documentation as (at least for me) it wasn't straightforward. Also, consider a WebView as radio buttons are not going to play nicely across platforms, and your problem would be easily solvable with jQuery.
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.
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 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);
I have an AdvancedDataGrid. One of the columns in the grid displayed with help of custom render. During the application run, I set another custom render to the same column. When I scroll data in the grid (change values for the custom renders) they display new view correctly.
I want that they dispaly new view automatically (when I set them): so I think I have to call them and tell tham to refresh rgeir views. Any idea how to do this?
Use invalidateList()