I need fire event from parent component to childs components like broadcast method in AngularJS. How it possible in RactiveJS?
P.S: For example i have a tabs with different content includes components, when tabs renders only one tab active(visible) other tabs are hidden. When i select other tab it become active and show content. At this moment tab should send event refresh down to the childs component to let they know that they must initialize or refresh (because while it was hidden it couldn't initialized right).
Within the tab component, observe that the tab has become "active" and call refresh:
this.observe('active', function(active){
if(active){ control.refresh() }
})
Events don't fire down the hierarchy.
One option would be to put the template in a section watching a visible or rendered flag. Then set the flag to true when the tab becomes active. If there is something outside of the template that needs to be handled, you can observe it from your script.
Out of curiosity, what can't initialize correctly while it's hidden? Or do you mean not rendered, as there is no DOM to access? In that case, you may want to look into decorators.
Related
I've worked thru the various jquery UI demos of drag and drop and sortable. These show how to get items from one list to another. One example even shows a shopping cart demo.
Am I missing something in that a item won't be part of a post to the server right? so what use is this other than reorganizing a display on a page?
Is it possible to adapt this to some sort of input field?
TIA
J
item won't be part of a post to the server right? so what use is this
other than reorganizing a display on a page?
Allowing users to reorganize the elements in the page is a nice feature, even if you aren't notified on the server. For example, by allowing users to drag and drop elements, you may store his current page layout in localStorage so that the next time the user visits your page, the layout is restored automatically. You don't need to be notified on the server side what the user preferences are.
All of these jQuery plugins (sortable, draggable, etc.) have functions that you can hook into and trigger some server side processing as well. For example, when a user drags and drops an element from one section of the screen to another, you can perfectly make an ajax request and do some processing on your end. This would provide a very nice user experience to the user.
For example:
$( ".selector" ).droppable({
drop: function( event, ui ) {
$.post('http://server/somection',data{...});//do something on the server-side
};
});
Absolutely! jsfiddle with demo here.
I have an Flex 4 application (not AIR) which has some floating windows that act essentially as modeless dialogs.
Right now, if two of these are open at once they function as siblings which are both active and whose controls are enabled for user interaction.
I now need to maintain some notion of which one is "active" in the application. I don't want to /disable/ the non-active ones so as to blur them or prevent input on their controls.
I basically want to replicate basic OS window management: when you click or type into a control in one window it comes to the front and its title bar looks "active" and the others then look "inactive". Just like with a bunch of explorers in Windows.
Can anyone clue me in on an approach?
Assuming that your pop up windows extend UIComponent, you should be able to listen to the FocusIn event to make your window active and the focusOut to make your window inactive.
Now containers do not usually dispatch the focus events; however children of the containers will. And since the focus event bubble, you can listen for them as part of your popup.
Personally I would handle this with what we call a Mediator... essentially a singleton UI controller, along with a slightly custom component and custom skin. On Popup, each window registers itself with the Mediator, so the mediator knows all the windows that are open, on close each de-registers itself, OnFocusIn on each component it notifies the mediator of this event, the mediator calls a method on every other panel to does the blurring or whatever.
The custom component can extend TitleWindow and add a property IsActiveWindow, then the custom skin can change it's appearance based on this property.
For pro points use RobotLegs to to inject the reference to the mediator into the components.
Good luck!
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);
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/