= DeltaSpike ProjectStage

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== Introduction

Project stages allow to use implementations depending on the current
environment. For example, you can implement a bean which creates sample-data for
system tests which gets activated only in case of ProjectStage
`SystemTest`.

_Besides custom ProjectStages_ it is possible to use the following
pre-defined ProjectStages:

* UnitTest
* Development
* SystemTest
* IntegrationTest
* Staging
* Production

The core provides a pluggable and type-safe approach for using project
stages in a project (it is also used within the framework). Furthermore,
`@Exclude` allows use of, for example, implementations annotated with
`javax.enterprise.inject.Alternative` for specific ProjectStages.
Besides the out-of-the-box ProjectStages it is possible to implement
_custom but type-safe_ ProjectStages which will be exposed by
DeltaSpike.

Resolving and using the ProjectStage:

[source,java]
-------------------------------------------------------------------------------
@Inject
private ProjectStage projectStage;

//...

boolean isDevProjectStage = ProjectStage.Development.equals(this.projectStage);
-------------------------------------------------------------------------------


== Custom Project Stages

It is possible to provide custom project stage implementations.
Therefore, you have to provide an implementation of the
`ProjectStageHolder` interface. In this class you nest the custom
ProjectStage implementations which have to be
`public static final class` and it is required to extend `ProjectStage`.
It is required to provide a `public static final` instance even though,
you will not use it directly.

ProjectStageHolder for custom project stage implementations:

[source,java]
-----------------------------------------------------------------------------------------
public class CustomProjectStageHolder implements ProjectStageHolder
{
    public static final class CustomProjectStage extends ProjectStage
    {
        private static final long serialVersionUID = 1029094387976167179L;
    }

    public static final CustomProjectStage CustomProjectStage = new CustomProjectStage();
}
-----------------------------------------------------------------------------------------

Configure your custom `ProjectStageHolder` in
`META-INF/services/org.apache.deltaspike.core.api.projectstage.ProjectStageHolder`.

NOTE: The file has to provide the _fully qualified_ class name of the custom
implementation of the `ProjectStageHolder` interface.

Usage of a custom project stage:

[source,java]
----------------------------------------------------------------------------
ProjectStage customProjectStage;
customProjectStage = ProjectStage.valueOf("CustomProjectStage");
//or
customProjectStage = CustomProjectStageHolder.CustomProjectStage;
//or
@Exclude(ifProjectStage = CustomProjectStageHolder.CustomProjectStage.class)
----------------------------------------------------------------------------


== Setting the active ProjectStage

For setting the ProjectStage which shall get used in your application
you can specify it in a few ways. The underlying mechanism used to
determine the string is the ConfigResolver.

.Example
------------------------------------------------
-Dorg.apache.deltaspike.ProjectStage=Development
------------------------------------------------

== ProjectStageProducer (for Third-party Portable Extensions)

`ProjectStageProducer` provides the producer method which allows to
inject the current ProjectStage. However, in some cases it is needed to
use ProjectStages also during the bootstrapping process of the CDI
container and you can not use injection. In such cases you can use
`ProjectStageProducer.getInstance().getProjectStage()` to resolve the
current ProjectStage. This helper also contains helpers for unit-tests
- e.g. `#setProjectStage`. However, those methods should not be needed
for users (we just need them for testing different ProjectStage
scenarios).