AsyncResource (Codename One API)

java.lang.Object
- java.util.Observable
- - com.codename1.util.AsyncResource<V>

Direct Known Subclasses:

AsyncMedia.PauseRequest, AsyncMedia.PlayRequest, BrowserWindow.EvalRequest, MessageEvent.PromptPromise, Oauth2.RefreshTokenRequest
```
public class AsyncResource<V>
extends Observable
```
A wrapper for an object that needs to be loaded asynchronously. This can serve as a handle for the object to be passed around irrespective of whether the object has finished loading. Conceptually this is very similar to Futures and Promises.

Since:

7.0

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`AsyncResource.AsyncExecutionException` Exception to wrap exceptions that are thrown during asynchronous execution.
`static class`	`AsyncResource.CancellationException` Exception thrown when the AsyncResource is cancelled.

Constructor Summary

Constructors
Constructor and Description

AsyncResource()

Constructors
Constructor and Description
`AsyncResource()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addListener(AsyncResource<V> resource)` Adds another AsyncResource as a listener to this async resource.
`static AsyncResource<Boolean>`	`all(AsyncResource<?>... resources)` Creates a single AsyncResource that will fire its ready() only when all of the provided resources are ready.
`static AsyncResource<Boolean>`	`all(Collection<AsyncResource<?>> resources)` Creates a single AsyncResource that will fire its ready() only when all of the provided resources are ready.
`Promise<V>`	`asPromise()` Wraps this AsyncResource object as a `Promise`
`void`	`await()` Waits and blocks until this AsyncResource is done.
`static void`	`await(AsyncResource<?>... resources)` Waits for a set of AsyncResources to be complete.
`static void`	`await(Collection<AsyncResource<?>> resources)` Waits for a set of AsyncResources to be complete.
`boolean`	`cancel(boolean mayInterruptIfRunning)` Cancels loading the resource.
`void`	`complete(V value)` Sets the resource value.
`void`	`error(Throwable t)` Sets the error for this resource in the case that it could not be loaded.
`AsyncResource<V>`	`except(SuccessCallback<Throwable> callback)` Sets callback to run if an error occurs.
`AsyncResource<V>`	`except(SuccessCallback<Throwable> callback, EasyThread t)` Sets callback to run if an error occurs.
`V`	`get()` Gets the resource synchronously.
`V`	`get(int timeout)` Gets the resource synchronously.
`V`	`get(V defaultVal)` Gets the resource if it is ready.
`boolean`	`isCancelled()` Checks if the resource loading was cancelled.
`static boolean`	`isCancelled(Throwable t)` Returns true if the provided throwable was caused by a cancellation of an AsyncResource.
`boolean`	`isDone()` Checks if the resource loading is done.
`boolean`	`isReady()` Checks if the resource is ready.
`void`	`onResult(AsyncResult<V> onResult)` Combines ready() and except() into a single callback with 2 parameters.
`AsyncResource<V>`	`ready(SuccessCallback<V> callback)` Runs the provided callback when the resource is ready.
`AsyncResource<V>`	`ready(SuccessCallback<V> callback, EasyThread t)` Runs the provided callback when the resource is ready.
`void`	`waitFor()` Wait for loading to complete.

Methods inherited from class java.util.Observable
addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - AsyncResource
```
public AsyncResource()
```
- Method Detail
  - cancel
```
public boolean cancel(boolean mayInterruptIfRunning)
```
    Cancels loading the resource.
    
    Parameters:
    
    mayInterruptIfRunning -
    
    Returns:
    
    True if the resource loading was cancelled. False if the loading was already done.
  - waitFor
```
public void waitFor()
```
    Wait for loading to complete. If on EDT, this will use invokeAndBlock to safely block until loading is complete.
  - get
```
public V get()
```
    Gets the resource synchronously. This will wait until either the resource failed with an exception, or the loading was canceled, or was done without error.
    If on edt, this uses invokeAndBlock to block safely.
    
    Returns:
    
    The wrapped resource.
    
    Throws:
    
    AsyncResource.AsyncExecutionException - if the resource failed with an error. To get the actual error, use Throwable.getCause().
  - get
```
public V get(int timeout)
      throws InterruptedException
```
    Gets the resource synchronously. This will wait until either the resource failed with an exception, or the loading was canceled, or was done without error.
    If on edt, this uses invokeAndBlock to block safely.
    
    Parameters:
    
    timeout - Timeout
    
    Returns:
    
    The wrapped resource.
    
    Throws:
    
    AsyncResource.AsyncExecutionException - if the resource failed with an error. To get the actual error, use Throwable.getCause().
    
    InterruptedException - if timeout occurs.
  - isCancelled
```
public static boolean isCancelled(Throwable t)
```
    Returns true if the provided throwable was caused by a cancellation of an AsyncResource.
    
    Parameters:
    
    t - The exception to check for a cancellation.
    
    Returns:
    
    True if the exception was caused by cancelling an AsyncResource.
    
    Since:
    
    7.0
  - get
```
public V get(V defaultVal)
```
    Gets the resource if it is ready. If it is not ready, then it will simply return the provided defaultVal.
    
    Parameters:
    
    defaultVal -
    
    Returns:
    
    Either the resource value, or the provided default.
  - isCancelled
```
public boolean isCancelled()
```
    Checks if the resource loading was cancelled.
    
    Returns:
  - isDone
```
public boolean isDone()
```
    Checks if the resource loading is done. This will be true even if the resource loading failed with an error.
    
    Returns:
  - isReady
```
public boolean isReady()
```
    Checks if the resource is ready.
    
    Returns:
  - ready
```
public AsyncResource<V> ready(SuccessCallback<V> callback,
                              EasyThread t)
```
    Runs the provided callback when the resource is ready.
    If an EasyThread is provided, then the callback will be run on that thread. If an EasyThread is not provided, and this call is made on the EDT, then the callback will be run on the EDT. Otherwise, the callback will occur on whatever thread the complete(java.lang.Object) call is called on.
    
    Parameters:
    
    callback - Callback to run when the resource is ready.
    
    t - Optional EasyThread on which the callback should be run.
    
    Returns:
    
    Self for chaining
  - ready
```
public AsyncResource<V> ready(SuccessCallback<V> callback)
```
    Runs the provided callback when the resource is ready.
    If this call is made on the EDT, then the callback will be run on the EDT. Otherwise, it will be run on whatever thread the complete() methdo is invoked on.
    
    Parameters:
    
    callback - The callback to be run when the resource is ready.
    
    Returns:
    
    Self for chaining.
  - except
```
public AsyncResource<V> except(SuccessCallback<Throwable> callback,
                               EasyThread t)
```
    Sets callback to run if an error occurs.
    If an EasyThread is provided, then the callback will be run on that thread. If an EasyThread is not provided, and this call is made on the EDT, then the callback will be run on the EDT. Otherwise, the callback will occur on whatever thread the complete(java.lang.Object) call is called on.
    
    Parameters:
    
    callback - Callback to run on error.
    
    t - Optional EasyThread to run callback on.
    
    Returns:
    
    Self for chaining.
  - except
```
public AsyncResource<V> except(SuccessCallback<Throwable> callback)
```
    Sets callback to run if an error occurs. If this call is made on the EDT, then the callback will be run on the EDT. Otherwise it will be run on whatever thread the error() method is invoked on.
    
    Parameters:
    
    callback - The callback to run in case of error.
    
    Returns:
  - complete
```
public void complete(V value)
```
    Sets the resource value. This will trigger the ready callbacks to be run.
    
    Parameters:
    
    value - The value to set for the resource.
  - error
```
public void error(Throwable t)
```
    Sets the error for this resource in the case that it could not be loaded. This will trigger the error callbacks.
    
    Parameters:
    
    t -
  - all
```
public static AsyncResource<Boolean> all(AsyncResource<?>... resources)
```
    Creates a single AsyncResource that will fire its ready() only when all of the provided resources are ready. And will fire an exception if any of the provided resources fires an exception.
    
    Parameters:
    
    resources - One ore more resources to wrap.
    
    Returns:
    
    A combined AsyncResource.
    
    Since:
    
    7.0
  - all
```
public static AsyncResource<Boolean> all(Collection<AsyncResource<?>> resources)
```
    Creates a single AsyncResource that will fire its ready() only when all of the provided resources are ready. And will fire an exception if any of the provided resources fires an exception.
    
    Parameters:
    
    resources - One ore more resources to wrap.
    
    Returns:
    
    A combined AsyncResource.
    
    Since:
    
    7.0
  - await
```
public static void await(Collection<AsyncResource<?>> resources)
                  throws AsyncResource.AsyncExecutionException
```
    Waits for a set of AsyncResources to be complete. If any of them fires an exception, then this method will throw a RuntimeException with that exception as the cause.
    
    Parameters:
    
    resources - The resources to wait for.
    
    Throws:
    
    AsyncResource.AsyncExecutionException
    
    Since:
    
    7.0
  - await
```
public void await()
           throws AsyncResource.AsyncExecutionException
```
    Waits and blocks until this AsyncResource is done.
    
    Throws:
    
    AsyncResource.AsyncExecutionException
  - await
```
public static void await(AsyncResource<?>... resources)
                  throws AsyncResource.AsyncExecutionException
```
    Waits for a set of AsyncResources to be complete. If any of them fires an exception, then this method will throw a RuntimeException with that exception as the cause.
    
    Parameters:
    
    resources - The resources to wait for.
    
    Throws:
    
    AsyncResource.AsyncExecutionException
    
    Since:
    
    7.0
  - addListener
```
public void addListener(AsyncResource<V> resource)
```
    Adds another AsyncResource as a listener to this async resource.
    
    Parameters:
    
    resource -
    
    Since:
    
    7.0
  - onResult
```
public void onResult(AsyncResult<V> onResult)
```
    Combines ready() and except() into a single callback with 2 parameters.
    
    Parameters:
    
    onResult - A callback that handles both the ready() case and the except() case. Use isCancelled(java.lang.Throwable) to test the error parameter of AsyncResult.onReady(java.lang.Object, java.lang.Throwable) to see if if was caused by a cancellation.
    
    Since:
    
    7.0
  - asPromise
```
public Promise<V> asPromise()
```
    Wraps this AsyncResource object as a Promise
    
    Returns:
    
    A Promise wrapping this AsyncResource.
    
    Since:
    
    8.0

Class AsyncResource<V>

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.Observable

Methods inherited from class java.lang.Object

Constructor Detail

AsyncResource

Method Detail

cancel

waitFor

get

get

isCancelled

get

isCancelled

isDone

isReady

ready

ready

except

except

complete

error

all

all

await

await

await

addListener

onResult

asPromise