tweed.context
Interface Context

All Superinterfaces:

Contextualized

All Known Implementing Classes:

DefaultContextFactory.DefaultContext

public interface Context

extends Contextualized

Describes an execution context. An instance of this class acts like a set of global variables, but in a restricted scope. A Context implementation must respect following rules:

• Immutability: Context instances MUST be immutable, references to Context member must not change once set. Context members (like logger) are not supposed to be immutable.
• Cascadability: Context objects may be cascaded, with the ability to propagate events upwards or downards (TODO: implement this).
• Logging and members creation order: Context's logger must be set creating any other members. Default implementations of Context members often take a Context object as input parameter, at least for using its Logger.
• Factory creation: due to the complexity of Context creation, a factory must used instead of Context constructor.

Version:

$Id$

Author:

Laurent Caillette

See Also:

DefaultContextFactory, ContextPatcher

Method Summary

ActionPerformer	getActionPerformer() Returns the ActionPerformer that processes ContextActions.
EventBus	getBus() Returns the event bus for this context.
Context	getContext() Allows to pass directly a Context object instead of a Contextualized.
InputValidationHub	getInputValidationHub() Returns the ValidationHub that every Binding uses implicitely.
CommandInvoker	getInvoker() Returns the CommandInvoker instance used server-side for executing Command instances on the server.
org.apache.avalon.framework.logger.Logger	getLogger() Returns the base Logger for this context.
boolean	isClientSide() Returns if the application is running client-side.
boolean	isServerSide() Returns if the application is running server-side.

Method Detail

getContext

public Context getContext()

Allows to pass directly a Context object instead of a Contextualized. Implementations must return this.

Specified by:

getContext in interface Contextualized

getLogger

public org.apache.avalon.framework.logger.Logger getLogger()

Returns the base Logger for this context.

Returns:

a non-null Logger instance.

getInvoker

public CommandInvoker getInvoker()

Returns the CommandInvoker instance used server-side for executing Command instances on the server.

Returns:

a CommandInvoker when called in the client context, null otherwise.

isClientSide

public boolean isClientSide()

Returns if the application is running client-side. It is guaranteed that the isServerSide() method will return the negation of isClientSide().

Returns:

true if running client-side, false otherwise.

isServerSide

public boolean isServerSide()

Returns if the application is running server-side. It is guaranteed that the isClientSide() method will return the negation of isServerSide().

Returns:

true if running server-side, false otherwise.

getBus

public EventBus getBus()

Returns the event bus for this context.

Returns:

a non-null EventBus instance if running client-side, null otherwise.

getInputValidationHub

public InputValidationHub getInputValidationHub()

Returns the ValidationHub that every Binding uses implicitely.

Returns:

a non-null InputValidationHub if running client-side, null otherwise.

getActionPerformer

public ActionPerformer getActionPerformer()

Returns the ActionPerformer that processes ContextActions.

Returns:

a non-null ActionPerformer if running client-side, null otherwise.