I need to call a function located in the parent component and make the call from the child component in Flex 3. Is there a way to access functions in the parent component from the child component? I know I can dispatch an event in the child and add a listener in the parent to call the function, but just wanted to know if could also directly call a parent function from a child. Thanks
You can use parentApplication
For example... if i have a main.mxml that calls a component we'll call child.mxml, i can call functions in main from within child by doing the following:
parentApplication.parentsFunctionName(parameters);
Related
I have a parent component with a people property. It uses a Service to get people Observable .
Then I have several children components. Everyone has #Input people from parent component. (To avoid http request on every child)
I would like to modify people array in each Child component without affecting the others (parent component and other child component)
It would be something like a new Observable copy or get data from observable.
I need the initial value of people in all components, but then I need to modify for each one.
How can I do this?
Thank you.
Do you need the people object to be an Observable in the child components? If this is not the case, you might want to change your code a bit. Instead of passing the Observable to the child components, just pass along the initial data via #Input()-Binding.
I have a mxml file that extends a parent class. The parent has a component that is hidden initially and only shown once a button is pressed. I would like to add a new child component to this hidden component from my extended mxml. Is there a way to access the super component and add the child once the buton is pressed? Maybe listen to an event?
Right now i have a solution that solves the problem by loading the hidden components but it´s not a nice solution.
super.advancedOptionsSearchBox.getChildren();
super.advancedOptionsSearchBox.addChildAt(getEANContainer(), 1);
If i do not call the getChildren I get a index out of bounds exception on the call to addChildAt method since the array of children is empty in the hidden component.
Couldn't you just set property
creationPolicy="all"
to your component? That way it's created even if it's initially not visible.
In short:
I need an event listener in a custom component so all its instances (without editing them) react at the same time, fired by a dispatched event in its parent container.
In detail:
I have a custom component with Tab navigator. (The tabs are intended to show different preferences for different Languages.)
I have a button bar with buttons for all the languages.
There are a lot of instances of the custom component.
I want to click in a button of the languages bar and get ALL the instances switched to the same tab (the custom component contains the logic to change the tab).
I can do it by adding the event listener for EACH INSTANCE of the custom component, so it calls an internal function that changes the tab. But it seems to be very coupled, isn't it?
I wonder if it can be done in the master CLASS of the component, so it listen for events in its parent container, whichever it is.
In my mind this code shoud work, but it doesn´t (obviously ill'use a custom event to pass the new language value):
this.parent.addEventListener("lang_change", this.change_tab);
This way I can just drop an instance of the component, and see it working for itself.
Thank you in advance
I need an event listener in a custom
component so all its instances
(without editing them) react at the
same time, fired by a dispatched event
in its parent container.
The very thing you want to do, by definition, breaks encapsulation. In an ideal world, a component should know nothing of it's parent. If the component needs to communicate with it's parent, it should dispatch an event. IF a parent needs to communicate to children it should call a public method on that child (or change a public property). From an encapsulation stand point, I cannot recommend that the child listen for events on the parent.
I want to click in a button of the
languages bar and get ALL the
instances switched to the same tab
(the custom component contains the
logic to change the tab).
So, then put a click handler for the button and do something like this:
public function onClick():void{
myCustomTabNavigator1.selectedIndex = 1
myCustomTabNavigator2.selectedIndex = 1
myCustomTabNavigator2.selectedIndex = 1
}
You can also set the selectedItem if you a reference to it. , If you have your custom TabNavigators in an Array, you can loop over them. IF the custom TabNavigators are child of your custom component you can create a method in that custom component to set the defaults and call that method on each component instead of setting selectedIndex directly.
I think you should to use some MVC model like:
Cairngorm
http://code.google.com/p/swizframework/
http://www.robotlegs.org/
http://puremvc.org/
I have a spark list control whose data is rendered using an itemrenderer. Basically the Item renderer lays out the data within a Panel.
The Panel has a LinkButton, which when clicked needs to pass an Id to the parent application. In the parent application I have a function that dispatches a custom event to its parent. I want to know how to call this function from the ItemRenderer.
I tried using parentDocument.outerfunction etc but it throws an error..
Any clues ?
I would have your item renderer dispatch a custom event that contains your Id, making sure that your event bubbles. Then in the parent application listen for that event and call the appropriate function. Hope that helps.
If I understand well you can try to call from the item renderer this.parentApplication or this.parent.parent.
The best way is to create a custom event and bubble .. and add an event listener for that event in parent document..
this is working I have test parentcomponent(this.owner.parent).function...owner is list and parent is the component in which list is placed e-g InvitationList(this.owner.parent).invitationAccepted(persist);
type cast the this.owner.parent to your parentclass
If you were using PureMVC, you could send a notification that the receiver would handle and perform the needed work. This is similar to firing a custom event and receiving it in the parent.
If I do something like:
<myComponent id="foo" title="bar" />
The parameters don't seem to be available immediately within the component. When do they become available?
From the Flex Docs:.
Flex dispatches the creationComplete event once for a component after the component is created and initialized.
Once a component is created and initialized, you can use its properties. Remember, all children components are created and initialized before their parents.
creationComplete will dispatch when all parts are completed.