The system.logics library perform some tasks based on whether a given condition holds true or not.
This task is heavily based on the Condition framework that can be found in the system.rules library.
In addition to the Rule condition, you can specify three different child actions based on the Action : elseif, then and else. All three subelements are optional. Both then and else must not be used more than once inside the if task. Both are containers for tasks, just like BatchTask and Chain tasks.
Example
// -------- Imports
var IfTask = system.logics.IfTask ;
var Do = system.process.Do ;
var ElseIf = system.logics.ElseIf ;
var EmptyString = system.rules.EmptyString ;
var Equals = system.rules.Equals ;
// -------- init
var task ;
var do1 = new Do() ;
var do2 = new Do() ;
var do3 = new Do() ;
var do4 = new Do() ;
do1.something = function() { trace("do1 ###") } ;
do2.something = function() { trace("do2 ###") } ;
do3.something = function() { trace("do3 ###") } ;
do4.something = function() { trace("do4 ###") } ;
// -------- behaviors
var error = function( message , action )
{
trace( "error:" + action + " message:" + message ) ;
};
var finish = function( action )
{
trace( "finish: " + action ) ;
};
var start = function( action )
{
trace( "start: " + action ) ;
};
trace(' -------- test 1');
task = new IfTask( new EmptyString('') , do1 , do2 ) ;
task.finishIt.connect(finish) ;
task.errorIt.connect(error) ;
task.startIt.connect(start) ;
task.run() ;
task.clear() ;
trace(' -------- test 2');
task.clear() ;
task.rule = new Equals(1,2) ;
task.addThen( do1 )
.addElse( do2 )
.run() ;
trace(' -------- test 3 : <elseIf>');
task.clear() ;
task.addRule( new Equals(1,2) )
.addThen( do1 )
.addElseIf
(
new ElseIf( new Equals(2,1) , do3 ) ,
new ElseIf( new Equals(2,2) , do4 )
)
.addElse( do2 )
.run() ;
trace(' -------- test 4 : <then> is already register');
task.clear() ;
task.throwError = true ;
try
{
task.addThen( do1 )
.addElse( do2 )
.addThen( do3 )
}
catch (e)
{
trace( e ) ;
}
trace(' -------- test 5 : <rule> is not defined');
try
{
task.run() ;
}
catch (e)
{
trace( e ) ;
}
trace(' -------- test 6 : <rule> is not defined and throwError = false');
task.throwError = false ;
task.run() ;