jQuery Forum

_setData and _getData are only for getting/setting options. The option
method delegates out to them.

Thank you guys for you responses. However neither of them satisfied
me, so I just looked into ui.core.js itself. Here is an excerpt:
...
_getData: function(key) {
    return this.options[key];
},
_setData: function(key, value) {
    this.options[key] = value;
    ...
},
...
In other words they just store and retrieve values to and from
this.options property. Very flat in fact. Hm...

That's all the base does. In a plugin implementation you'll do a lot more. For example, see
<a href="http://jquery-ui.googlecode.com/svn/trunk/ui/jquery.ui.dialog.js">http://jquery-ui.googlecode.com/svn/trunk/ui/jquery.ui.dialog.js</a>
So my response was assuming you were asking why inside a plugin implementation you sometimes see the option being set directly and sometimes see it being set through _setData. And the difference is whether you want all these side-effects that are added to the plugin's own _setData.
- Richard

Right. But I never knew that it just stores arguments in the very same
this.options property :)
Thanks for the tip anyway.