org.apache.tapestry5.services
Interface Heartbeat

All Known Implementing Classes:

HeartbeatImpl

public interface Heartbeat

Allows for deferred execution of logic, useful when trying to get multiple components to coordinate behavior. A component may add a command to be executed "at the end of the heartbeat". The classic example of this is a Label and the field it labels; since we don't know which order the two will render, we can't tell if the field's id is correct until after both have rendered.

The Heartbeat is injected into components via the Environmental annotation.

Method Summary

void	begin() Begins a new Heartbeat.
void	defer(Runnable command) Adds a new command to the current Heartbeat.
void	end() Executes all commands since the most recent begin().

Method Detail

begin

void begin()

Begins a new Heartbeat. Heartbeats nest. Every call to begin() should be matched by a call to end().

end

void end()

Executes all commands since the most recent begin().

defer

void defer(Runnable command)

Adds a new command to the current Heartbeat. The command will be executed by end().

Parameters:

command - command to be executed at the end of the heartbeat