Question

First off: I’m fairly new to zk. I try to create a component that does a lot of client side processing (think image editing). Therefore, I would like to create a widget that creates it’s own child widgets at ‘construction time’.

But although I do find a lot of documentation on how to instantiate widgets, I fail to find a hint on when to do it. In other words:

How does ZK call my widget, what method should I override in my widget javascript to generate children?

Answer 1

Not sure what’s your purpose for adding child.

But by default the widget initialize lifecycle is

1.widget.$init() //JS widget constructor

2.widget.redraw_ // output html , it’s actually the “mold” .

3.widget.bind_ // binding event to html , and the desktop is inited.

If you are planing to build a composite widget ,
like the calendar in Datebox , you could reference to the $init function in Datebox. 🙂

Let me know if you need further information.

https://github.com/zkoss/zk/blob/5.0/zul/src/archive/web/js/zul/db/Datebox.js

function _initPopup () {
    this._pop = new zul.db.CalendarPop();
    this._tm = new zul.db.CalendarTime();
    this.appendChild(this._pop);
    this.appendChild(this._tm);
}

$init: function() {
    this.$supers('$init', arguments);
    this.afterInit(_initPopup);
    this.listen({onChange: this}, -1000);
},