Time events in Javascript

Revision as of 16:56, 27 March 2013

Timer and Timeouts in JavaScript

The Engine class from JavaScript has 4 methods to process and cancel timeouts:

NOTE: The time interval values are in milliseconds.

• Engine.setInterval(callback,expireInterval)

This method will create a repeated time event. Each time expireInterval passes, callback method is called.

This method returns an id witch can be used to cancel the timer with the help of Engine.clearInterval method.

• Engine.clearInterval(id)

This method clears a time event installed with Engine.setInterval method.

The id parameter represents the value returned by Engine.setInterval method.

The method returns true if the time event was cleared.

• Engine.setTimeout(callback,expireInterval)

This method crates an one shoot time event. After the expireInterval has passed the callback method is called and callback method is called; after this the time event is cleared.

This method returns an id, witch can be used to clear the timeout event.

• Engine.clearTimeout(id)

This method clears a time event installed with Engine.setTimeout method.

Examples:

var intervalId;

function timeoutCallback() {
    Engine.debug(Engine.DebugAll,"Got timeout event!");
    Engine.clearInterval(intervalId);
}

function intervalCallback() {
    Engine.debug(Engine.DebugAll,"Got interval event!");
}

Engine.setTimeout(timeoutCallback,10000);
intervalId = Engine.setInterval(intervalCallback,1000);

In the example above the method intervalCallback will be called each second. The timeoutCallback method will be called after 10 seconds and it will clear the interval timeout. So after 10 seconds no message will be shown.