A Play application.
A Play application.
Application creation is handled by the framework engine.
If you need to create an ad-hoc application, for example in case of unit testing, you can easily achieve this using:
val application = new DefaultApplication(new File("."), this.getClass.getClassloader, None, Play.Mode.Dev)
This will create an application using the current classloader.
Loads an application.
Loads an application. This is responsible for instantiating an application given a context.
Application loaders are expected to instantiate all parts of an application, wiring everything together. They may be manually implemented, if compile time wiring is preferred, or core/third party implementations may be used, for example that provide a runtime dependency injection framework.
During dev mode, an ApplicationLoader will be instantiated once, and called once, each time the application is reloaded. In prod mode, the ApplicationLoader will be instantiated and called once when the application is started.
Out of the box Play provides a Java and Scala default implementation based on Guice. The Scala implementation is the play.api.inject.guice.GuiceApplicationLoader.
A custom application loader can be configured using the application.loader
configuration property.
Implementations must define a no-arg constructor.
Helper to provide the Play built in components.
Helper that provides all the built in components dependencies from the application loader context
A full configuration set.
A full configuration set.
The underlying implementation is provided by https://github.com/typesafehub/config.
the underlying Config implementation
The environment for the application.
The environment for the application.
Captures concerns relating to the classloader and the filesystem for the application.
The root path that the application is deployed at.
The classloader that all application classes and resources can be loaded from.
The mode of the application.
A Play logger.
Runs through underlying logger configuration.
Typical logger interface.
Generic exception for unexpected error cases.
Defines an application’s global settings.
Defines an application’s global settings.
To define your own global settings, just create a Global
object in the _root_
package.
object Global extends GlobalSettings { override def onStart(app: Application) { Logger.info("Application is started!!!") } }
(Since version 2.5.0) Use dependency injection
This object provides a set of operations to create Configuration
values.
This object provides a set of operations to create Configuration
values.
For example, to load a Configuration
in a running application:
val config = Configuration.load() val foo = config.getString("foo").getOrElse("boo")
The underlying implementation is provided by https://github.com/typesafehub/config.
The default global settings if not defined in the application.
High-level API for logging operations.
High-level API for logging operations.
For example, logging with the default application logger:
Logger.info("Hello!")
Logging with a custom logger:
Logger("my.logger").info("Hello!")
Application mode, either DEV
, TEST
, or PROD
.
High-level API to access Play global features.
High-level API to access Play global features.
Note that this API depends on a running application. You can import the currently running application in a scope using:
import play.api.Play.current
Contains the Cache access API.
Contains data manipulation helpers (typically HTTP form handling)
Contains data manipulation helpers (typically HTTP form handling)
import play.api.data._ import play.api.data.Forms._ val taskForm = Form( tuple( "name" -> text(minLength = 3), "dueDate" -> date("yyyy-MM-dd"), "done" -> boolean ) )
Contains the JDBC database access API.
Contains the JDBC database access API.
Example, retrieving a connection from the 'customers' datasource:
val conn = DB.getConnection("customers")
Contains standard HTTP constants.
Contains standard HTTP constants. For example:
val text = ContentTypes.TEXT val ok = Status.OK val accept = HeaderNames.ACCEPT
Contains the internationalisation API.
Contains the internationalisation API.
For example, translating a message:
val msgString = Messages("items.found", items.size)
Play's runtime dependency injection abstraction.
Play's runtime dependency injection abstraction.
Play's runtime dependency injection support is built on JSR-330, which provides a specification for declaring how dependencies get wired to components. JSR-330 however does not address how components are provided to or located by a DI container. Play's API seeks to address this in a DI container agnostic way.
The reason for providing this abstraction is so that Play, the modules it provides, and third party modules can all express their bindings in a way that is not specific to any one DI container.
Components are bound in the DI container. Each binding is identified by a BindingKey, which is typically an interface that the component implements, and may be optionally qualified by a JSR-330 qualifier annotation. A binding key is bound to a BindingTarget, which describes how the implementation of the interface that the binding key represents is constructed or provided. Bindings may also be scoped using JSR-330 scope annotations.
Bindings are provided by instances of Module.
Out of the box, Play provides an implementation of this abstraction using Guice.
The Module class for information on how to provide bindings.
Contains various APIs that are useful while developing web applications.
Contains the Controller/Action/Result API to handle HTTP requests.
Contains the Controller/Action/Result API to handle HTTP requests.
For example, a typical controller:
object Application extends Controller { def index = Action { Ok("It works!") } }
Contains test helpers.
Contains the public API for Scala developers.
Access the current Play application
import play.api.Play.current
Read configuration
Use the logger
Logger.info("Hello!")
Define a Plugin
Create adhoc applications (for testing)