I have an Alloy app structured with a one window divided in two views: a sidebar menu view on the left and a main view on the right.
Each time the user click on a different menu-item in the sidebar I remove all children attached to the main view and load the view/controller related to that menu-item and attach it to the main view. My question: is this sufficient? If the removed view had event listeners attached to elements inside it, are they clean up too or not?
Have I to keep a reference to each controller I have instantiated and call controller.destroy() and controller.off() before I load the new view/controller or is not necessary?
I am asking because with views without window is not possible to attach a cleanup function to the "onclose" event because the UI.View elements can't be "closed" (only windows).
So which is the correct way to handle this situation in Titanium?
The event listeners may keep a reference especially you add them with Ti.APP.addEventListeners.
So, you should remove event listeners manually when you remove all children view.
Related
Let me explain the my scenario. I am using ExtJS5. I have got a view component (let us name is viewOne) contain two combo boxes, button search and some action button, on click of search button the grid is populated. This viewOne is in a parent view component (viewParent). I need to load a second view (viewTwo) on selecting some grid row and clicking some action button a new view is loaded (viewTwo) in the parentView. When I come back from viewTwo to viewOne I need old values of combo boxes to re perform the search.
Currently I am storing the values of combo boxes in a store and set then when the after view render and call search. We have discarded card layout for this implementation.
I wanted to know how this can be done via Ext.state , I cannot find any example on the same that is close solution to my problem. Any other way of doing this ?
State seems reasonable for that. First of all you must set StateProvider (by calling Ext.state.Manager.setProvider) to instance of class which extends Ext.state.Provider.
Then state should work for you. Only thing that you must remember is to set stateful property to true and set stateId of the component.
Usually you don't need to save state by yourself. All built-in stateful components have defined state events. When such state event occur (eg. expand on panel) then state is saved automatically. You can customize state events by calling addStateEvents in initComponent.
To provide custom component state you should override applyState and getState methods. When you combine it with addStateEvents you have all what you need.
Example: http://jsfiddle.net/48jw81da/16/
hi i've been using backbonejs for almost 2 years now and am just starting out on marionettejs with my first app at this website.
the reason for my question is that in my app i have a Layout with a 2 composite view rendered as dropdown list and table (which updates itself whenever we change the selection on the dropdown list).
what i did was for the "change" event on my dropdown list, i have an MyApp.vent.trigger() which i have a listener at the MyApp.addInitializer() function that updates the other compositeview (the table below the dropdown list). actually for the whole app i have almost 6 of this triggers inside itemViews and compositeViews and listeners are inside the addInitializer() for some of the other functions.
i just want to know if i did this right? or is this how dev in marionettejs normally is?
thank you
Yes, that's the recommended idea. However, you don't necessarily need to use the top-level vent attribute: each sub-app and view has their own (scoped) event manager. In addition, you don't necessarily need to add the listener in an addInitializer.
Here's an example (from my Marionette book):
trigger an event at the view scope: https://github.com/davidsulc/marionette-gentle-introduction/blob/master/assets/js/apps/contacts/list/list_view.js#L15 This uses the triggers hash, but you could also do this.trigger("my:event") from within the view, like here: https://github.com/davidsulc/marionette-gentle-introduction/blob/master/assets/js/apps/contacts/list/list_view.js#L29
listening to the events (and retriggering them if necessary): https://github.com/davidsulc/marionette-gentle-introduction/blob/master/assets/js/apps/contacts/list/list_controller.js#L48 and https://github.com/davidsulc/marionette-gentle-introduction/blob/master/assets/js/apps/contacts/list/list_controller.js#L38
Hope this helps !
We are working with an application that uses prism and MVVM for healthcare tracking operations.
Within this application, we have registered views in primary regions, and scenarios in which clicking on a cell in a grid (in this case a xamdatagrid - Infragistics) will launch another region via the prism region popup behaviors constructs.
So, when we click on the cell, a cellactivation operation in the code behind for that view is called which then calls a method in the view model to .RequestNavigate to the view that is registered for the 'secondary' popup region (thus launching what appears to be a dialog over the existing application).
I am attempting to pass an object from the parent view (the values of the record in the grid) to the child view that is launched in the popup, and have found that none of the expected operations is working.
I have a mediator object that we are using to pass information back from children to parents, but this does not work the other direction because the publish/notify operations for the mediator require the child view to 'already' be instantiated before the parent publishes to pass that information.
I'm finding that the event aggregator structures built into the Prism.Events classes don't appear to be working either (I'm assuming because of the same publish/subscribe issues). I can publish an event through the event aggregator from the parent view and subscribe in the child view, but I have to launch the child view 'twice' in order to get the event tied to the event aggregator operation to actually fire.
I understand this is rather vague (minus the code), but I'm looking more for a start point, or anyone that's run into the same kinds of issues. The bullet point scenario is as follows:
Parent view already instantiated in existing region.
Clicking on cell in parent view instantiates (navigates to) child view in popup region.
Same click operation needs to pass an object from the parent view to the child view so that the child view can filter its own data based on that object.
Operations are constructed using Prism/MVVM.
Any help, suggestions, pointers, ideas would be awesome.
We had the same scenario and ended up with creating a UiService that are injected to our ViewModels. Our ViewModel base class has a SetModel method which the UiService calls when navigating, for sending parameters to the destination view.
By example:
Clicking a button in the existing View.
Source ViewModel calls UiService ShowView(data).
UiService calls RequestNavigate for the requested view.
UiService calls SetModel on the destination ViewModel (by accessing the DataContext of the requested view) to pass in the data from the source ViewModel.
Depending what you want to pass it can be pretty simple with INavigationAware
Sounds like you want to pass something like query string - parameters, etc. Code to open window will be like this:
var query = new UriQuery
{
{ "MailItemKey", this.SelectedMailItem.MailItemKey.ToString(CultureInfo.InvariantCulture) }
};
RegionManager.RequestNavigate(RegionNames.Popup, typeof(MailItemView).Name + query.ToString());
And inside MailItemViewModel which is our popup's VM code is like this:
public override void OnNavigatedTo(NavigationContext navigationContext)
{
var mailItemKey = int.Parse(navigationContext.Parameters["MailItemKey"]);
}
If you want to pass custom objects - it will be more complex. I would look for MVVM in the box samples - there is some code on how it's done. I had to re-work it whole lot and code is not really copy-pasteable.
Sounds like a perfect use of a RegionContext.
Parent view contains a region that can have multiple "child" views activated in it. They need to share some context or data. Set a region context and bind or pass whatever info all the "child" views in the Region will need.
See the Prism samples around RegionContext.
I'm developing a Mac Application. The application has a common source view on the left and a detail view on the right which is the main part of the whole window.
It's like a Master-Detail relationship, but each element in the source view require another detail view. In fact, I have designed a specific NSViewController for each element in the source view.
If I'm switching between these NSViewControllers, that means If I select another element in the source view, I remove the current view and add the view of the newly selected NSViewController. Everytime I change the NSViewController, its state will be lost. When the user comes back to that NSViewController, he has to start over.
My question now is: How can I save the state of the NSViewController, so that I can switch between these without losing its states and can continue where I have left?
Two considerations about your problem:
Keep model data in model classes. This means that you can always recreate a view controller and set its represented object provided the model classes have kept the changes made via the view controller. When you need to instantiate a view controller, set its represented object to (a representation of) a model class.
When removing a view from its superview, you do not necessarily need to release its corresponding view controller. Instead, you can keep strong references to all view controllers in your window controller/application delegate, so no state is actually lost.
Use NSArchiver. Implement archiving/unarchiving in your dealloc/init methods and store each view controller's state in a file named after the class (if you have one item per view controller policy). Otherwise think of some simple naming convention and use it.
I have a Prism/SL3 application with a tab control and each page of the tab control is a "Region" that has its own view and viewModel. when I want to validate the main page, I call dataForm.ValidateItem(), then I go to all the child views and do the same. the problem is, only the pages which user has clicked on them (on the tab page), get instantiated and the pages that are never shown, don't have their view instantiated, thus I can't validate them.
any help?
I created a psuedo work around for this. It's very hacky, but it does work. My example involved walking the visual tree (up and down) to find respective controls that are invalid and then "expanding" the selected item. I have used an accordian in my example, but have also tested this with tab:
http://thoughtjelly.wordpress.com/2009/09/24/walking-the-xaml-visualtree-to-find-a-parent-of-type-t/
HTH,
Mark
EDIT: Link updated.