Return-Path: <dev-return-47504-archive-asf-public=cust-asf.ponee.io@felix.apache.org>
X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io
Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io
Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183])
	by cust-asf2.ponee.io (Postfix) with ESMTP id B79D5200BCB
	for <archive-asf-public-internal@cust-asf2.ponee.io>; Thu, 24 Nov 2016 16:09:01 +0100 (CET)
Received: by cust-asf.ponee.io (Postfix)
	id B6469160B11; Thu, 24 Nov 2016 15:09:01 +0000 (UTC)
Delivered-To: archive-asf-public@cust-asf.ponee.io
Received: from mail.apache.org (hermes.apache.org [140.211.11.3])
	by cust-asf.ponee.io (Postfix) with SMTP id F3401160B20
	for <archive-asf-public@cust-asf.ponee.io>; Thu, 24 Nov 2016 16:09:00 +0100 (CET)
Received: (qmail 50285 invoked by uid 500); 24 Nov 2016 15:09:00 -0000
Mailing-List: contact dev-help@felix.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:dev-help@felix.apache.org>
List-Unsubscribe: <mailto:dev-unsubscribe@felix.apache.org>
List-Post: <mailto:dev@felix.apache.org>
List-Id: <dev.felix.apache.org>
Reply-To: dev@felix.apache.org
Delivered-To: mailing list dev@felix.apache.org
Received: (qmail 50202 invoked by uid 99); 24 Nov 2016 15:08:59 -0000
Received: from arcas.apache.org (HELO arcas) (140.211.11.28)
    by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 24 Nov 2016 15:08:59 +0000
Received: from arcas.apache.org (localhost [127.0.0.1])
	by arcas (Postfix) with ESMTP id C000F2C03DF
	for <dev@felix.apache.org>; Thu, 24 Nov 2016 15:08:59 +0000 (UTC)
Date: Thu, 24 Nov 2016 15:08:59 +0000 (UTC)
From: "Pierre De Rop (JIRA)" <jira@apache.org>
To: dev@felix.apache.org
Message-ID: <JIRA.13023211.1480000097000.361392.1480000139783@Atlassian.JIRA>
In-Reply-To: <JIRA.13023211.1480000097000@Atlassian.JIRA>
References: <JIRA.13023211.1480000097000@Atlassian.JIRA> <JIRA.13023211.1480000097857@arcas>
Subject: [jira] [Created] (FELIX-5425) Add support for OSGi Promise in
 DM-lambda
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394
archived-at: Thu, 24 Nov 2016 15:09:01 -0000

Pierre De Rop created FELIX-5425:
------------------------------------

             Summary: Add support for OSGi Promise in DM-lambda
                 Key: FELIX-5425
                 URL: https://issues.apache.org/jira/browse/FELIX-5425
             Project: Felix
          Issue Type: New Feature
          Components: Dependency Manager Lambda
    Affects Versions: org.apache.felix.dependencymanager-r8
            Reporter: Pierre De Rop
            Assignee: Pierre De Rop
            Priority: Minor


When you use the new DM-lambda API, and when a component needs to get the result of an asynchronous operation before being activated and registered in the OSGi service registry, you can now use a new "future dependency" which allows to define a CompletableFuture (jdk8), and when the CF completes, then the result is injected in the component (like if it was a ServiceDependency), then the component is started and registered.

For example, if your component needs to download a web page before being activated and registered, you can do this:

{code}
 public class Activator extends DependencyManagerActivator {
   public void init(BundleContext ctx, DependencyManager dm) throws Exception {  
      // Download a web page asynchronously, using a CompletableFuture:
        	
      String url = "http://felix.apache.org/";
      CompletableFuture<String> page = CompletableFuture.supplyAsync(() -> downloadSite(url));				

      // The component depends on a log service and on the content of the Felix site.
      // The lambda passed to the "withFuture" method configures the callback that is 
      // invoked with the result of the CompletableFuture (the page content).
      
      component(comp -> comp
          .provides(MyService.class)
          .impl(MyComponent.class)
          .withService(LogService.class)
          .withFuture(page, result -> result.complete(MyComponent::setPage)));
   }
 }
 
 public class MyComponent implements MyService {
   volatile LogService log; // injected.
   
   void setPage(String page) {
      // injected by the FutureDependency.
   }
   
   void start() {
      // the web page has been downloaded and we can now register in the OSGI registry.
   }

   @Override
   void doService() {
        ...
   }
 }
{code}

Now, it should be investigated if the DM-lambda API could also support the OSGI Promise API (in addition to the jdk8 CompletableFuture).




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)