I advise using ViewStack for this instead of states. Be aware of
deferred instantiation issues with ViewStack (and TabNavigator, and
Accordion)
Where you implement a functionality is your choice. What matters is the
run-time document object model (component relationships). There are
*many* ways to communicate between components. Use events for loose
coupling. For tight coupling, see the discussion below
Tracy
Communicating between Components:
Note: for loose coupling use events. But that is another topic.
A non-trivial flex application is component based. While all of the
built-in controls are components, the question of communicating between
components most often arises when you are using a custom component. A
custom component, whether implemented in mxml or ActionScript, has its
own scope. Within that component (Application is a component too!),
all sibling child controls share the same scope, so you can refer to
controls by their id. If the controls(components) have public
properties or methods, you can reference those members directly through
the id:
mx:TextInput id=textinput1 text=test value .../
mx:Text id=text1 ... text={textinput1.text} .../
Ok, so far, its a duh right?
When you use custom components in a Flex app, at run time they make a
document object model hierarchy (DOM). Each subcomponent has its own
scope and code within that component can't *directly* reference the
member properties or methods of its sibling subcomponents.
So again, within a component, code can reference children directly, as
in the example above. But there are two other cases inherent in a
hierarchy. You might want to reference up, to get to public members
of the parent, grandparent, etc, or 'down, to get to a grandchild.
Accessing members in the parent:
On an ordinary component DOM, you can reference the parent component
using the .parent property. Say that a control with id=textinput1
exists in the parent of the current component. then you could do:
mx:Text id=text1 ... text={parent.textinput1.text}
.../
Accessing members in the main application:
Components can be nested, sometimes very deeply. If the reference you
want is all the way at the top-level, main application (the one with the
mx:Application tag), you could do
{parent.parent.parent.textinput1.text}, but you would have to count the
component levels just right. Instead, you can use
Application.application to get to that scope:
mx:Text id=text1 ...
text={Application.application.textinput1.text} .../
You can shoretn this style of reference by importing
mx.core.Application, and assigning Application.application to a
variable, like _app, the doing (_app.textinput1.text)
Accessing components of a child component (grandchildren):
Say that in this case, a child component has the TextInput control you
want to reference. First, make sure the child component has an id:
myComp:MyCustomComp id=mycc1 .../
Then, in the same scope (the same component/file that contains mycc1
above) you can say:
mx:Text id=text1 ... text={mycc1.textinput1.text} .../
Accessing a nested component:
As mentioned above you can go up the hierarchy using
parent.parent You can also go down the hirearchy using id
references:
mx:Text id=text1 ...
text={mycc1.mycc11.mycc.12.textinput1.text} .../
Additional notes:
If you are using SWFLoader to load an entire Application, you can
reference the immediate parent application using parentDocument. You
can also use Application.application to reach the main app, as shown
above.
Accessing members of an application loaded by SWFLoader is a bit more
complicated. See the example here:
http://www.cflex.net/showFileDetails.cfm?ObjectID=690
From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On
Behalf Of cool buddy
Sent: Tuesday, March 11, 2008 4:18 PM
To: flexcoders@yahoogroups.com
Subject: [flexcoders] going to next page after submission to backend..
HI all,
I have written a application where in the user enters his details and
hits submit button ..on submission the details are sent to the
database..It should go to the next page and display some messagehow
do we handle this in flex..i was thinking of using states..but the above
database processing i have included in a component...
does anyone know how to handle this scenario..please post it..
Thanks,
D
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