We are trying to get the server name, session id browser info... to keep the information in the MDC for logging.
For this we are trying to add a listener in the RequestCycle of the onBeginRequest() of IRequestCycleListener.
I have added a class as follows:
public class RequestRListener implements IRequestCycleListener
{
#Override
public void onBeginRequest(RequestCycle cycle)
{
//TODO
}
}
Now where to add the listener to get the above mentioned informations ?
In your class that extends WebApplication or AuthenticatedWebApplication in the init() function.
You need to get the request cycle listeners and add your new listener to the list.
So, if you want to output the requested URI you'd do something like this:
getRequestCycleListeners().add(
new AbstractRequestCycleListener()
{
public void onBeginRequest(RequestCycle cycle)
{
if( cycle.getRequest().getContainerRequest() instanceof HttpServletRequest )
{
HttpServletRequest containerRequest =
(HttpServletRequest)cycle.getRequest().getContainerRequest();
System.out.println("URI="+containerRequest.getRequestURI() );
}
};
}
);
Getting the browser info can be done almost anywhere, not necessarily just in the request.
String userAgent = WebSession.get().getClientInfo().getUserAgent();
Related
I'm using Castle Windsor as DI Container and have following question:
Is it possible to get informed by the container each time, any object was created by the container and get a reference to this object?
I want to check after each resolve, if the resolved object implements a special interface (e.g. IEmergencyStop). I want to register this object at a special service (EmergencyStopHelper).
Following an example:
interface IEmergencyStop
{
void Stop();
}
interface IMotor : IEmergencyStop
{
void Run();
}
class Motor : IMotor
{
}
class EmergencyStopHelper
{
List<IEmergencyStop> emergencyStopList = new List<IEmergencyStop>();
public void Register(IEmergencyStop aClass)
{
emergencyStopList.Add(aClass);
}
public void StopAll() => emergencyStopList.ForEach( x => x.Stop());
}
container.Register(Component.For<IMotor>().ImplementedBy<Motor>().LifestlyleTransient());
container.Register(Component.For<EmergencyStopHelper>());
// TODO: any magic code which calls EmergencyStopHelper.Register(...)
// after following resolve
IMotor aMotor = container.Resolve<IMotor>();
var emergencyStop = container.Resolve<EmergencyStopHelper>();
emergencyStop.StopAll();
I have an MVVM Cross application running on Windows Phone 8 which I recently ported across to using Portable Class Libraries.
The view models are within the portable class library and one of them exposes a property which enables and disables a PerformanceProgressBar from the Silverlight for WP toolkit through data binding.
When the user presses a button a RelayCommand kicks off a background process which sets the property to true which should enable the progress bar and does the background processing.
Before I ported it to a PCL I was able to invoke the change from the UI thread to ensure the progress bar got enabled, but the Dispatcher object isn't available in a PCL. How can I work around this?
Thanks
Dan
All the MvvmCross platforms require that UI-actions get marshalled back on to the UI Thread/Apartment - but each platform does this differently....
To work around this, MvvmCross provides a cross-platform way to do this - using an IMvxViewDispatcherProvider injected object.
For example, on WindowsPhone IMvxViewDispatcherProvider is provided ultimately by MvxMainThreadDispatcher in https://github.com/slodge/MvvmCross/blob/vnext/Cirrious/Cirrious.MvvmCross.WindowsPhone/Views/MvxMainThreadDispatcher.cs
This implements the InvokeOnMainThread using:
private bool InvokeOrBeginInvoke(Action action)
{
if (_uiDispatcher.CheckAccess())
action();
else
_uiDispatcher.BeginInvoke(action);
return true;
}
For code in ViewModels:
your ViewModel inherits from MvxViewModel
the MvxViewModel inherits from an MvxApplicationObject
the MvxApplicationObject inherits from an MvxNotifyPropertyChanged
the MvxNotifyPropertyChanged object inherits from an MvxMainThreadDispatchingObject
MvxMainThreadDispatchingObject is https://github.com/slodge/MvvmCross/blob/vnext/Cirrious/Cirrious.MvvmCross/ViewModels/MvxMainThreadDispatchingObject.cs
public abstract class MvxMainThreadDispatchingObject
: IMvxServiceConsumer<IMvxViewDispatcherProvider>
{
protected IMvxViewDispatcher ViewDispatcher
{
get { return this.GetService().Dispatcher; }
}
protected void InvokeOnMainThread(Action action)
{
if (ViewDispatcher != null)
ViewDispatcher.RequestMainThreadAction(action);
}
}
So... your ViewModel can just call InvokeOnMainThread(() => DoStuff());
One further point to note is that MvvmCross automatically does UI thread conversions for property updates which are signalled in a MvxViewModel (or indeed in any MvxNotifyPropertyChanged object) through the RaisePropertyChanged() methods - see:
protected void RaisePropertyChanged(string whichProperty)
{
// check for subscription before going multithreaded
if (PropertyChanged == null)
return;
InvokeOnMainThread(
() =>
{
var handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(whichProperty));
});
}
in https://github.com/slodge/MvvmCross/blob/vnext/Cirrious/Cirrious.MvvmCross/ViewModels/MvxNotifyPropertyChanged.cs
This automatic marshalling of RaisePropertyChanged() calls works well for most situations, but can be a bit inefficient if you Raise a lot of changed properties from a background thread - it can lead to a lot of thread context switching. It's not something you need to be aware of in most of your code - but if you ever do find it is a problem, then it can help to change code like:
MyProperty1 = newValue1;
MyProperty2 = newValue2;
// ...
MyProperty10 = newValue10;
to:
InvokeOnMainThread(() => {
MyProperty1 = newValue1;
MyProperty2 = newValue2;
// ...
MyProperty10 = newValue10;
});
If you ever use ObservableCollection, then please note that MvvmCross does not do any thread marshalling for the INotifyPropertyChanged or INotifyCollectionChanged events fired by these classes - so it's up to you as a developer to marshall these changes.
The reason: ObservableCollection exists in the MS and Mono code bases - so there is no easy way that MvvmCross can change these existing implementations.
If you don't have access to the Dispatcher, you can just pass a delegate of the BeginInvoke method to your class:
public class YourViewModel
{
public YourViewModel(Action<Action> beginInvoke)
{
this.BeginInvoke = beginInvoke;
}
protected Action<Action> BeginInvoke { get; private set; }
private void SomeMethod()
{
this.BeginInvoke(() => DoSomething());
}
}
Then to instanciate it (from a class that has access to the dispatcher):
var dispatcherDelegate = action => Dispatcher.BeginInvoke(action);
var viewModel = new YourViewModel(dispatcherDelegate);
Or you can also create a wrapper around your dispatcher.
First, define a IDispatcher interface in your portable class library:
public interface IDispatcher
{
void BeginInvoke(Action action);
}
Then, in the project who has access to the dispatcher, implement the interface:
public class DispatcherWrapper : IDispatcher
{
public DispatcherWrapper(Dispatcher dispatcher)
{
this.Dispatcher = dispatcher;
}
protected Dispatcher Dispatcher { get; private set; }
public void BeginInvoke(Action action)
{
this.Dispatcher.BeginInvoke(action);
}
}
Then you can just pass this object as a IDispatcher instance to your portable class library.
Another option that could be easier is to store a reference to SynchronizationContext.Current in your class's constructor. Then, later on, you can use _context.Post(() => ...) to invoke on the context -- which is the UI thread in WPF/WinRT/SL.
class MyViewModel
{
private readonly SynchronizationContext _context;
public MyViewModel()
{
_context = SynchronizationContext.Current.
}
private void MyCallbackOnAnotherThread()
{
_context.Post(() => UpdateTheUi());
}
}
I want to get a list of all containers in the current platform. This question is similar, but the answer is obsolete and the method is by querying to the AMS agent. Is there any simpler way out than to communicate via ACL messages which I think is complex, there should be a way out to get a simple list of containers. Thanks for your help
You can achieve this by using the AMSSubscriber class and listen to the events when a container is added or removed. See sample code below:
public class myAgent extends Agent {
private ArrayList<ContainerID> availableContainers = new ArrayList<ContainerID>();
/**
* Agent initializations
**/
protected void setup() {
AMSSubscriber subscriber = new AMSSubscriber(){
protected void installHandlers(Map handlers){
EventHandler addedHandler = new EventHandler(){
public void handle(Event event){
AddedContainer addedContainer = (AddedContainer) event;
availableContainers.add(addedContainer.getContainer());
}
};
handlers.put(IntrospectionVocabulary.ADDEDCONTAINER,addedHandler);
EventHandler removedHandler = new EventHandler(){
public void handle(Event event){
RemovedContainer removedContainer = (RemovedContainer) event;
ArrayList<ContainerID> temp = new ArrayList<ContainerID>(availableContainers);
for(ContainerID container : temp){
if(container.getID().equalsIgnoreCase(removedContainer.getContainer().getID()))
availableContainers.remove(container);
}
}
};
handlers.put(IntrospectionVocabulary.REMOVEDCONTAINER,removedHandler);
}
};
addBehaviour(subscriber);
}
}
Reference: 1) Developing multi-agent systems with JADE
By Fabio Luigi Bellifemine, Giovanni Caire, Dominic Greenwood (page 111)
2) Jade API
Does anyone know of a framework, preferably some way to have the Flex compiler run an extension or perhaps just a build step that we could generate strongly typed proxy classes of our application's data models.
There are 2 main things we want to do with the proxy's:
At runtime we want to lazily parse and instantiate the instance as accessed (similiar to how Java's Hibernate has Lazy proxy objects)
In an editor application we want to implement setter calls so we can track which objects have been modified
The Proxy is really necessary in this situation beyond things like programatically setting up ChangeWatcther's because we need to track Array adds/remove and possibly track "reference" objects so that when a "reference key" is changed we know to save those objects that are referencing it by key
In the first case we want the proxy to basically abstract when that object is loaded from serialized data, but still pass around references of it with the same public properties and data access pattern if it were the real object.
Basically the proxy would instantiate the object the first time a method is called on it.
I know we could use some AS3 byte-code libraries like as3-commons-bytecode.
Or possibly repurposing the GraniteDS Code Generation.
I'd prefer to generate code because it is a deterministic thing and it'd be nice if we could have a way to debug it at runtime easier.
Does anyone know if I could do something like MXMLC does when it generates AS3 code from MXML files.
Also is there anyway to control "when" in the compilation pipeline I can generate code, because we have a lot of data objects using public fields instead of getter/setters, but that are [Bindable] and so if I could generate the proxy based on the generated getter/setter methods that would work.
Here's an example application data object and proxy classes:
[Bindable]
public class PersonDTO implements Serializable {
private var _name:String;
private var _age:Number
public function get age():Number {
return _age;
}
public function set age(a:Number):void {
_age = a;
}
public function get name():String {
return _name;
}
public function set name(n:String):void {
_name = n;
}
public void readObject(data:*) {
//...
}
}
// GENERATED CLASS BASED ON PersonDTO
public class LazyProxy_PersonDTO extends PersonDTO {
private var _instance:PersonDTO = null;
private var _instanceData:*;
private function getInstance():void {
if (_instance == null) {
_instance = new PersonDTO();
_instance.readObject(_instanceData);
}
}
override public function get age():Number {
//Ensure object is instantiated
return getInstance().age;
}
override public function get name():String {
//Ensure object is instantiated
return getInstance().name;
}
}
// GENERATED CLASS BASED ON PersonDTO
public class LogChangeProxy_PersonDTO extends PersonDTO {
//This will be set in the application
public var instance:PersonDTO;
//set by application
public var dirtyWatcher:DirtyWatcherManager;
override public function set age(a:Number):void {
dirtyWatcher.markAsDirty(instance);
instance.age = a;
}
}
Digging a little deeper into AS3-Commons byte code library it looks like they support generating proxy classes and interceptors.
http://www.as3commons.org/as3-commons-bytecode/proxy.html
public class DirtyUpdateInterceptor implements IInterceptor {
public function DirtyUpdateInterceptor() {
super();
}
public function intercept(invocation:IMethodInvocation):void {
if (invocation.kind === MethodInvocationKind.SETTER) {
if (invocation.arguments[0] != invocation.instance[invocation.targetMember]) {
invocation.instance.isDirty = true;
}
}
}
}
I have a form with a search field.
When user press enter key, I use httpservice to send a query to mySQL database.
In some case (a lot) there are several record, so a new window is opening to show those record with a datagrid to let user chose the good result.
My problem is how to send selected information to the first window (with text field).
I gess that dispatch event is the way but I don't found how to use!
Can you help me to find a solution.
Thanks
If you are trying to communicate within an MDI environment I suggest that you use some kind of shared model ( aka Mediator or Presentation Model ) that keeps a contract between the desired windows.
class SelectionPM{
[Bindable]
public var selectedItem:Object;
}
Use case:
Window1 has an instance of SelectionPM, when you open Window2 you pass
SelectionPM instance to it, then update SelectionPM.selectedItem
property on changing selection in the Window2 datagrid. That will
propagate the binding chain up to Window1, where you can use the
SelectionPM.selectedItem as you wish.
Ideally you would use an IoC container for model injection but that is another story.
That might seem like a lot of work but if you keep this methodology across your app you will benefit from it.
Cheers!
Here's a set of four classes as a basis. Obviously you don't want to be doing the actual work in the constructors as below.
public class App
{
public static var eventDispatcher:EventDispatcher = new EventDispatcher();
public function App()
{
new Window1();
}
}
class AppEvent extends Event
{
public static const DATA_READY:String = "APPEVENT.DATA_READY";
public var data:Object;
public function AppEvent( type:String, data:Object )
{
super( type );
this.data = data;
}
}
class Window1
{
public function Window1()
{
App.eventDispatcher.addEventListener( AppEvent.DATA_READY, onDataReady );
...DO STUFF...
new Window2();
}
private function onDataReady( evt:AppEvent ) : void
{
...DO STUFF WITH "evt.data"....
}
}
class Window2
{
public function Window2()
{
...GET DATA FROM SERVER AND PUT IT IN "data"...
App.eventDispatcher.dispatchEvent( new AppEvent( AppEvent.DATA_READY, data ) );
}
}
</pre>