Play-ParSeq is a Play module which seamlessly integrates ParSeq with Play Framework.

ParSeq is a Java framework for writing async code, which has several advantages over Java CompletionStage or Scala Future, e.g. ParSeq Trace for async code's runtime visualization, async code reuse via Task composition and taking control of async code's lifecycle.

Key features:

• Executes ParSeq Task and generates Java CompletionStage or Scala Future, which allows ParSeq Tasks to be used for executing Play Action.
• Converts from Java Callable<CompletionStage<T>> or Scala () => Future[T] to ParSeq Task, which allows existing code using Play native APIs to be integrated with ParSeq Tasks.
• Supports ParSeq Trace.
• Provides both Scala and Java API.
• Requires Play 2.6.

Every change on master branch, for example a merged pull request, lands a new version in Bintray's JCenter and Maven Central. This way we continuously deliver improvements in small batches, ensuring quality and compatibility. Check out latest release notes! Release automation is handled by Shipkit (http://shipkit.org) and configured in shipkit.gradle.

1. Put the preset module PlayParSeqModule into your application.conf.

   ...
   play.modules.enabled += "com.linkedin.playparseq.j.modules.PlayParSeqModule"
   ...
   

2. Inject PlayParSeq into your Controller.

   ...
   private final PlayParSeq _playParSeq;
   @Inject
   public Sample(final PlayParSeq playParSeq) {
       _playParSeq = playParSeq;
   ...

3. Use PlayParSeq in your Action.

   ...
   public CompletionStage<Result> demo() {
       // Convert to ParSeq Task
       Task<String> helloworldTask = _playParSeq.toTask("helloworld", () -> CompletableFuture.completedFuture("Hello World"));
       // Run the Task
       return _playParSeq.runTask(Http.Context.current(), helloworldTask).thenApply(Results::ok);
   }
   ...

1. Put additional preset module for ParSeqTraceModule into your application.conf.

   ...
   play.modules.enabled += "com.linkedin.playparseq.trace.j.modules.ParSeqTraceModule"
   ...
   

2. Put ParSeq Trace resource route into your routes.

   ...
   ->         /                       com.linkedin.playparseq.trace.Routes
   ...
   

3. Annotate your Action by putting @With(ParSeqTraceAction.class).

   ...
   @With(ParSeqTraceAction.class)
   public CompletionStage<Result> demo() {
   ...

4. Access [original-route]?parseq-trace=true will display ParSeq Trace Viewer for your original request if your application is in dev mode.

1. Put the preset module PlayParSeqModule into your application.conf.

   ...
   play.modules.enabled += "com.linkedin.playparseq.s.modules.PlayParSeqModule"
   ...
   

2. Inject PlayParSeq into your Controller.

   ...
   class Sample @Inject()(playParSeq: PlayParSeq, cc: ControllerComponents) extends AbstractController(cc) {
   ...

3. Use PlayParSeq in your Action.

   ...
   def demo = Action.async(implicit request => {
       // Convert to ParSeq Task
       val helloworldTask = playParSeq.toTask("helloworld", () => Future("Hello World"))
       // Run the Task
       playParSeq.runTask(helloworldTask)
           .map(Ok(_))
   })
   ...

1. Put additional preset module for ParSeqTraceModule into your application.conf.

   ...
   play.modules.enabled += "com.linkedin.playparseq.trace.s.modules.ParSeqTraceModule"
   ...
   

2. Put ParSeq Trace resource route into your routes.

   ...
   ->         /                       com.linkedin.playparseq.trace.Routes
   ...
   

3. Inject ParSeqTraceAction into your Controller.

   ...
   class Sample @Inject()(playParSeq: PlayParSeq, parSeqTraceAction: ParSeqTraceAction, cc: ControllerComponents) extends AbstractController(cc) {
   ...

4. Use parSeqTraceAction.async for your Action.

   ...
   def demo = parSeqTraceAction.async(implicit request => {
   ...

5. Access [original-route]?parseq-trace=true will display ParSeq Trace Viewer for your original request if your application is in dev mode.

Please see /sample.

A: Please first make sure you annotated your Action with @With(ParSeqTraceAction.class) in Java, or you used parSeqTraceAction.async for your Action in Scala. Then check whether you meet all ParSeqTraceSensor requirements of showing ParSeq Trace. And also don't forget using runTask in your Action. Please also note that ParSeq Trace Viewer will be blocked by strict Content Security Policy rules because of some inline scripts and styles.

A: If you don't want to use the preset modules, please write your own Module and register it by putting into your application.conf. Almost every part of Play-ParSeq follows the DI, so you can easily replace any part with your own.

A: Yes. If you don't want to use the default value, please insert the corresponding settings into your application.conf.

A: Yes. Play-ParSeq supports this. However, you shouldn't be running multiple Tasks, otherwise the order of execution might not be accurate, which minimizes the benefits of ParSeq.

A: Yes.

A: You can follow the instructions below:

1. Implements ParSeqTraceSensor with your own requirements.

   ...
   // Java
   @Singleton
   public class MySensorImpl implements ParSeqTraceSensor {
       @Override
       public boolean isEnabled(final Http.Context context, final ParSeqTaskStore parSeqTaskStore) {
           return [your-requirements];
       }
   }
   ...

   ...
   // Scala
   @Singleton
   class MySensorImpl extends ParSeqTraceSensor {
       override def isEnabled(requestHeader: RequestHeader, parSeqTaskStore: ParSeqTaskStore): Boolean =
           [your-requirements]
   }
   ...

2. Create your own Module to include the binding of your ParSeqTraceSensor.

   ...
   // Java
   public class MyModule extends Module {
       @Override
       public Seq<Binding<?>> bindings(final Environment environment, final Configuration configuration) {
           return seq(
               bind(ParSeqTraceSensor.class).to(MySensorImpl.class),
               [other-bindings]);
       }
   }
   ...

   ...
   // Scala
   class MyModule extends Module {
       override def bindings(environment: Environment, configuration: Configuration): Seq[Binding[_]] = Seq(
           bind[ParSeqTraceSensor].to[MySensorImpl],
           [other-bindings])
   }
   ...

3. Register your Module in your application.conf.

   ...
   play.modules.enabled += [package-of-MyModule]
   ...
   

4. Have two ice-creams.

A: It's not possible with the current ParSeqTaskStore implementation, which is based on Play Framework's Java or Scala specific request APIs. Play 3.0 will hopefully provide a common underlying request which will remove this limitation. However, you can inject your own implementation of ParSeqTaskStore, such as shared cache or local file, to make this happen.

Copyright 2015 LinkedIn Corp.

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