Brilliant! Thank you. :-)
> On Jul 18, 2018, at 14:46, Peter Kriens <peter.kri...@aqute.biz> wrote:
>
> A really elegant solution to these problems is to use a Promise …
>
> 1) Create a Deferrred
> 2) Execute your item code through the promise of the deferred
> 3) When the Executor reference is set, you resolve the deferred
>
>
> @Component
> public class Foo {
> Deferred<Executor> deferred = new Deferred<>();
>
> @Reference
> void setExecutor( Executor e) { deferred.resolve(e); }
>
> @Reference( multiple/dynmaic)
> void addItem( Item item) {
> deferred.getPromise().thenAccept ( executor -> … )
> }
> }
>
> This will automatically process your items after the executor is set. It
> think it also easily extends to multiple dependencies but would have to
> puzzle a bit. If you’re unfamiliar with Promises, I’ve written an app note,
> ehh blog, recently about 1.1 Promises
> http://aqute.biz/2018/06/28/Promises.html
> <http://aqute.biz/2018/06/28/Promises.html>. They really shine in these
> ordering issues.
>
> Kind regards,
>
> Peter Kriens
>
>
>
>> On 18 Jul 2018, at 00:16, David Leangen via osgi-dev <osgi-dev@mail.osgi.org
>> <mailto:osgi-dev@mail.osgi.org>> wrote:
>>
>>
>> Hi!
>>
>> I have a component that acts a bit like a whiteboard provider. It looks
>> something like this:
>>
>> public class MyWhiteboard
>> {
>> boolean isActive;
>>
>> @Reference MyExecutor executor; // Required service to execute on an Item
>>
>> @Reference(multiple/dynamic)
>> void bindItem( Item item )
>> {
>> if (isActivated)
>> // add the Item
>> else
>> // Store the item to be added once this component is activated
>> }
>>
>> void unbindItem( Item item )
>> {
>> // Remove the item
>> }
>>
>> @Activate
>> void activate()
>> {
>> // execute non-processed Items
>> isActivate = true;
>> }
>> }
>>
>> The MyExecutor must be present before an Item can be processed, but there is
>> no guarantee as to the binding order. All I can think of doing is ensuring
>> that the Component is Activated before processing.
>>
>> My question is: is there a more elegant / simpler / less error prone way of
>> accomplishing this?
>>
>>
>> Thanks!
>> =David
>>
>>
>> _______________________________________________
>> OSGi Developer Mail List
>> osgi-dev@mail.osgi.org <mailto:osgi-dev@mail.osgi.org>
>> https://mail.osgi.org/mailman/listinfo/osgi-dev
>
_______________________________________________
OSGi Developer Mail List
osgi-dev@mail.osgi.org
https://mail.osgi.org/mailman/listinfo/osgi-dev
