Flex :: Make Cairngorm Commands ALWAYS Work Synchronously
Oct 1, 2009
I see the benefit of asynchronous commands (waiting for server responses...) but in my flex app it creates me more problem than anything. Here's what I want: EVERY command executes only after the previous one returned (to result or fault function) And I'd like to do this as easily as possible.. by the way the GUI must become irresponsive (maybe a wait message) while a long command is being executed (I could show the wait message in the execute function and remove it in the fault or result function..)
I have a dataGrid with a dataProvider "documents"A column of the datagrid has a labelFunction that gets the project_id field of the document, and returns the project name, from a bindable variable "projects"Now, I dispatch the events to download from the server the documents and the projects, but If the documents get downloaded before the projects, then the label function gives an error (no "projects" variable)Therefore, I must serialize the commands being executed: the getDocuments command must execute only after the getProjects command.In the real world, though, I have dozens of resources being downloaded, and those command are not always grouped together (so I can't for example execute the second command from the onSuccess() method of the first, because not always they must be executed together..)..
Is there a way to make event flow occur synchronously?
Basically this is my scenario. I have a single method call that gets triggered by a server request. I want to be able to notifiy subscribers that the method has/is executing so that they may return a result. By modifying an attribute of the actual event object, the method can return that result to the server dynamically. Eg:
Code: //method invoked by server public function whatever(...parameters):* { var event:MyEvent = new MyEvent(MyEvent.TYPE);
[Code]....
This code works around 70% of the time, but sometimes I see things are really happening asynchronously in Flash Player's event flow. Is there anything I can do to regulate this and make sure it happens synchronously?
I am using an component, and currently have a dataProvider working that is anArrayCollection (have a separate question about how to make this an XML file... but I digress).Variable declaration looks like this:
[Bindable] private var _dpImageList : ArrayCollection = new ArrayCollection([ {"location" : "path/to/image1.jpg"},
I want to store some test data for a FlexUnit test in small XML files in my Flex project, and access them trivially for the flex test. How can I load these bits of data synchronously? HTTPService is the way I'd be loading them _a_synchronously, but adding event handlers to my test cases seems like a bit of overkill.
I have a Game swf that uses keyboard Listeners. They workjust fine when the swf's played directly. HOWEVER, after the Game'sbeen loaded into a parent Preloader swf - which is playing from anhtml - , the keyboard Listeners don't function at all.In the Keyboard Listeners do I have to reference the parent?
I am using an component, and currently have a dataProvider working that is an ArrayCollection (have a separate question about how to make this an XML file... but I digress). Variable declaration looks like this:
I found a lot of interesting info in the 'hidden features of...' series. I am very new to cairngorm . What are some of the hidden features of cairngorm.
I am not using FlexBuilder, I'm using the free Flex SDK with TextMate. I'm having some trouble figuring out what this FlexBuilder process actually does behind all the nice dialogs and things, so that I can do the same thing by tweaking whatever the relevant file is, but Googling just points me at similar instructions telling me to use FlexBuilder.
I ran into a problem.I'm doing a GIS program using flex. There's a map in my Application,when I click one icon on the map,windowA pops up,when I click a link inside windowA,windowB pops up,but here my problem coming out,when I close windowB and click the link inside windowA another time,Two windowB pop up...
From what I understand a framework reduces complexity in areas that are common, like a log-in system. I use ASP.NET MVC at work and have done some work in Zend Framework but do not get how a framework helps with client side development. The reason ASP.NET MVC is used at work is for Unit Testing - does a Flex framework help with this too? why I should or should not use a framework with Flex?
I wish to do my project in mvc pattern. so I chose cairngorm framework and just read some of the document about this framework.But I cant understand deeply to do project using this framework. Have any methods or examples to study doing project in cairngorm framework??
In Cairngorm (Flex Framework), there is Model Locator Pattern, which is similar to Global variables, is it a right pattern, Adobe is saying for flex its best pattern
I have a TitleWindow that I open up... and I have 6 states defined.I am using the Presentation model pattern for all of my views. When I tell my window to go to XXX state, the controls have to initialize since the states in flex use lazy loading. so... my PM code that says myTextArea.text bombs out and say "cannot access..." so as a work around, I made some creationComplete events on my controls to register the control with the PM. So when the state changes, the textarea finally initializes and on creationComplete calls PM.registerTextArea() which sets a reference to it. then in that function I run my code... myTextArea.text.. etc.
This seems like such a ugly hack that I hate it. Is there any way to wait until the entire state in created then call code on the PM? I have tried enterstate... but this event seems to fire before the state controls are ready.I tried to add a comment, but I guess editing is the only way I can do this...I am doing something slightly off straight PM. Every view has a viewController (as I call them). Its kinda my own hybrid of a delegate / dataprovider. But this is moot. It's the flex component lifecycle when dealing with states that is the pain.if you change state.. there is no event to say "all my components in this state are ready".only event to say "we changed state". so my code that fires on state change is trying to talk to components that aren't ready yet.So from what I see, there seems to be no design pattern or perfect way to ensure that all components are created in a state unless using creationComplete on every component in the state to register it is ready... if you don't, you get a race condition. Regardless of frameworks or design patterns, this seems to be a root issue.
I am trying to attach video to a display once I get to that state. This is done via addchild. regardless of where I do it.. I need to know that the videoDisplay is done loading before I call addchild. I even tried currentStateChange event since docs say that fires last... but alas.. the components in the state are still initializing. So it seems that creationComplete is my only option. Maybe the only sane way to keep to clean code is to create the entire thing(videodisplay and video) using as once the state is entered. I just hoped the flex framework had events to ehlp me here rather than buiilding everything on the fly in as.
I need to read the URL that the browser shows when a Flex application is called because I would to reference it in a mxml configuring Cairngorm remote objects. The goal I would reach is to automatically configure Cairngorm services from environment to environment (dev,test,qa,prod) without statically set the value in the mxml or other ActionScript. Since the Flex client is deployed in the root of the war of the webapp, it's enough to read where the browser is pointing.
I have written a class that is doing so: public class ConfigServer { public function ConfigServer() { var loaderUrl:String = FlexGlobals.topLevelApplication.loaderInfo.loaderURL; var urlToSet:String = <loaderURL-string-manipulation>; _serverUrl = urlToSet; [Code] .....
But whenever I call the ConfigServer constructor and for every (known to me) technique I applied (statics or singletons or public ro so on), I have always had the same error: TypeError: Error #1009: Cannot access a property or method of a null object reference. at org.fao.fapda.util::ConfigServer()[C:devworkspacesFAPDA runkFAPDA-clientsrcorgfaofapdautilConfigServer.as:8]
Cairngorm services initialization is done as follow: <fx:Declarations><cut/> <services:FAPDAServices id="services"/> <cut/></fx:Declarations> And the problem is that FAPDAServices.mxml is read runs before FlexGlobals is valid. Is there a point in the Flex Application lifecycle where such loaderURL is defined so that I can construct ConfigServer? When in startup events that initialization in done?
I'm having a hard time building a Cairngorm Flex3 app that connects to a rails app. I'm used to rails DRY approad, and the Convention over Configuration thing too.. and Cairngorm in awful at these.
How do you keep you flex code as DRY as possible? I've implemented a generic delegate to avoid a delegate for each command, at least.
I have a few values in Java VO, and using cairgorm framework, i had mapping the Java VO to Action script VO in Flex and given same variables name as java Vo variables name. Now the Vo is mapping fine and when looking the result all variables are displaying as null. Can i know the reason for that.Java returning list of VO's.
how to incorporate FileReference method like Upload into a Cairngorm architecture.Specifically, I would think to fire an event with the File in it, and that's fine. But how would one then be able to listen for e.g. Progress Events?One thing I thought is to have the delegate fire off progress events that are listened for in the View.
Could tools like SWFAddress be used in some clever ways to alleviate an existing client-server architecture. I see possibilities to even introduce REST-like pattern mapping or something like that.
What I am currently doing is following all the Cairngorm guidleines, which has already led to a bunch of commands which all make sense, but inclusing the business delegates, and all that stuff, I am getting into a hard time extending and refactoring the application Anyway, what I thought of was somehow reducing the number of application events flying around, and the number of commands responding to them. Actualy, I am quite OK even coupling the view with some logic, if I can get rd of some layer complexity.
What I mean by that: perhaps, I could bind a button click to a url pattern (or use SWFaddress to change the url globally). On the other end, I wll be waiting for changes of the url, reformat it, and pass it onto a service delegate, which has the necessary mappings in mind, so it knows what method to call, or it could even pass the url directly to an HTTPSErvice. The delegate will then deal with the server response, and update the model, which through the bindings will update the view.
I am not going to completely ditch commands. I thing that they are good for scheduling of the internal interactions (within the client itself), but I'd like to abstain from using them for communication with the server.
I recently completed a project for a custom report UI in Flex. Now, I've been tasked with creating a new application that is essentially a "lite" version of the original UI. It will include only a few of the options that are in the original application. Also, it needs to be a separate application.
I do not want to duplicate my code, so I am planning on moving a bunch of the classes from the original application to a new library that can be shared by both applications. However, I'm trying to figure out how to make this work in my MVC environment.
For example, I have an Accordion component that lets users filter several items. Each Accordion child is an instance of a custom component with two lists (one for entities available for selection, the other for the entities the user has selected). Each child component has properties bound to the Model and functions that call Cairngorm Events.[code]...
I have created a few Event and Command classes for use in my Cairngorm projects.For example, I created an class that extends URL... that allows me to set callback functions upon completion or failure of the corresponding Command. To accomplish this, I also had to create a new Class that implements com.adobe.cairngorm.commands.ICommand that I extend for all Commands in my projects.Now, I want to use these two classes across all of my Cairngorm applications. What is the best way to do this? Should I just edit the Cairngorm source for CairngormEvent and ICommandand recompile the Cairngorm MVC (is that even possible)? Or add my two classes to the Cairngorm source and recompile the Cairngorm MVC? Or should I just add them to a shared library?I've chose the third option for now, but this requires that I reference the Cairngorm library in both my library and each project. I am wondering if there is a better practice and what the benefits are.
I seem to be getting the following error when I try to access a Remote Java class (on Spring/BlazeDS) from the Flex/Cairngorm application. I am going crazy at the moment trying to see what is wrong
How swffit (http://swffit.millermedeiros.com/) can be used? I mean in my project I have dynamically expanding flash application, so once the expanding part riches the bottom I see standard flash scroll bar. Not browser scrollbar...
Here is how I defined my application:
public function addPanel(evt:Event):void { var panel:Panel = new Panel(); panel.name = "new"; panel.title = "new"; panel.height = 30; panel.width = 100; this.addChild(panel); SWFFit.fit('my_flash', 800, 600); }
public function main(event:Event):void{ SWFFit.fit('my_flash', 800, 600);
<div> <a href="http://www.adobe.com/go/getflashplayer"><img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" title="Get Adobe Flash player" /></a><br /> You need <a href="http://www.adobe.com/go/getflashplayer">Flash Player 8</a> and allow javascript to see the content of this site.. </div> <!--[if !IE]>--> </object> <!--<![endif]--> </object>
</body> </html>
Will be happy to hear any feedback,
Added fixes described in answer 1. but come across interesting issue: e.g. browser scroll bar appears only on browser window resize, not when clicking add button...
