how to naviaget one mxml page to another via action script
the navigatTourl() method used for webpages but, if want to navigate another mxml page mean how to show
When creating a Flex Application, the page analogy does not work very well. In an HTML site, each page is a self contained entity with no real relation to any other page. However, a Flex Application is a single self contained entity; and that entity can have lots of screens, or views.
To navigate between views in a Flex Application there are a lot of ways. Here are three approaches:
You could use States
You could use a Navigator container, such as a ViewStack or a TabNavigator.
You could toggle the visible property of your UI Components.
Generally, the first two options would be used for massive changes. The third option would be used for minor changes.
Related
I'm trying to implement a popup window (NativeWindowType.UTILITY) in an AIR 2.7 application that uses Swiz for dependency injection.
I have followed the Swiz guidelines that I've been able to find, and implemented ISwizAware on the class that creates the window, and I am calling _swiz.registerWindow() before opening the window, and dependency injection works fine on the window itself after this.
However, the problem I am running into is that I have a child view within that window, and I have a mediator that uses the [ViewAdded] and [ViewRemoved] tags. Neither the view added nor view removed functions are triggering. I'm thinking the issue is either:
The child view is not correctly registering with Swiz.
The swiz instance doesn't know about the beans (I have tried manually adding the bean however, which didn't have any effect).
The ViewAdded and ViewRemoved metadata tags simply aren't working because each NativeWindow object has its own stage instance.
Anyone know more about this?
Popups are a special case since they don't get added under the same display tree as your application. Under Stage (the main wrapper for Flash Player), you'll have Application where your code resides for Swiz, but Popup is in a separate layer above Application. Since they're siblings, Swiz cannot listen in for when the popup is being added to the Stage.
The way around this is to either set the properties of the popup manually (which is normally the easiest way) or manually add the popup to Swiz's awareness. For this you'll have to look at the documentation since I haven't touched Swiz in a long time.
I have a web-application whose UI is implemented in GXT (ext GWT).
Now I want to switch to Flex but as the application is so large that I cannot afford to start migrating the whole application at once.
So I have decided to migrate slowly. So what I want is to bring up a Flex panel on the click of a GXT's button.
Basically the idea is how to make Flex components listen to the events generated by GXT's component.
Flex app is ultimately an SWF and GWT gives you JavaScript; you can use ExternalInterface to invoke an SWF's methods from JavaScript code and vice-versa. Checkout the addCallback method - the linked page has some sample code in it.
In the examples for RobotLegs, it appears that mediators are used on every button/textArea, rather than on the custom component that contains these children. This would be very time consuming would it not?
From Joel Hooks InsideRia Example
Dependency injection works better with
unambiguous classes. What this means
is that by extending TextArea into our
new MessageView class, we are creating
a specific view component for the
dependency injection to act upon. This
is important if our application were
to have several TextAreas that served
different purposes. By dividing up our
classes in this way, we are clearly
defining the intent of the class and
allowing for the dependency injection
tools to do their jobs effectively.
No, don't mediate every child component. Your components should be organized into groups that perform related actions. In the examples the components are extremely simple and do not reflect what a real application would look like.
One rule of thumbs I use is thinking if that component needs any communication with the rest of the application, or if its only a part of a whole. Keep in mind that mediator are only intended to serve as a bridge between the view and the app.
For example, if I've a view with a form (asume a login form) I don't mediate all the child components (the textfields, the buttons, etc.) because it would be pointless and would have a proliferation of classes and objects on runtime. When I do the form I think, what does the view by its own? and what the other parts of the app should do with it?
When the user fills the form and clicks a button, the view dispatches an event (LoginRequestEvent, for this case), and then the mediator should redispatch that event, making the mediator very lean.
But with practice of the framework, you'll come up with this feel of what you shold mediate. For instance, in one app I mediate every item renderer of a list, and on other I mediate a view stack with two or three navigation contents.
Hope it helps
I have a Flex application with three different views. Only one view is shown at a time, and the choice of view depends on what part of the application the user is working with. If it had been an ordinary HTML webapp I would have created three different HTML-templates/pages for each view.
What is the recommended way to handle such application views in Flex?
The behavior you want is usually accomplished by using a ViewStack component. In MXML you declare child containers for each view you want, but only one gets shown at a time. You can change which one is shown programmatically whenever conditions are met by setting selectedIndex on your ViewStack. By default the first child container is displayed when run. Another approach is to declare and use states in your container and change currentState whenever you need to change the view. Hope that helps.
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.