jquery widget, _create or _init

Question

Some jquery plugin extend widget use _create method, while others use _init method, can someone explain the differences between the two?

Also any guidance on when it is better to extend widget or directly extend jquery.fn?

score 18 · Answer 1 · answered Oct 21 '10 at 02:11

18

From the jQuery UI Developer Guide:

Once the element is created, all other calls to the widget name where the first parameter is not a string will call the _init() method; if options are passed, the .option() method will be called before the _init() method

answered Oct 21 '10 at 02:11

Mottie

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Unfortunately, link is now toast. – Joe Atzberger Mar 03 '14 at 18:47
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[Try this link to the api](https://api.jqueryui.com/jquery.widget/#method-_init) or [this blog post](http://www.erichynds.com/blog/tips-for-developing-jquery-ui-widgets) – Mottie Mar 04 '14 at 03:08

Ken Browning · Accepted Answer · 2010-10-20T23:14:32.727

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The downside to extending widget (as opposed to $.fn) is that you create a dependency on jquery-ui which defines the widget "class". That dependency could be expensive for users of your plugin that don't also use jquery-ui.

As far as _create vs _init goes, I'm pretty sure that _init came first and then in a recent revision they introduced and favor _create. I might be wrong about this, but I believe that _init is still supported. If it is then there shouldn't be any differences between the two.

edited Oct 20 '10 at 23:14

answered Oct 20 '10 at 22:49

Ken Browning

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Good point on widget. Do you have any replacement of widget if I don't want to introduce additional dependency to jqueryui? – Gelin Luo Oct 23 '10 at 12:23
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You could just rip out the widget code and include it in your .js file. There was talk about moving widget into jquery itself instead of jqueryui but I don't know if that's been slated for a specific release or not yet. – Ken Browning Oct 23 '10 at 20:47
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There is a different between the _init and _create. _create is called only once. _init will be called multiple time as mentionned from @fudgey – jsgoupil Jul 07 '11 at 21:36

score 3 · Answer 3 · answered Mar 14 '17 at 22:46

A widget has three phases:

+-------+----------------+---------------+--------------------------------------------------------------------------------------------+
| Phase | Name           | jQuery Method | Description                                         |  
+-------+----------------+---------------+--------------------------------------------------------------------------------------------+
|     1 | Creation       | _create       | First time the widget is applied to an element, it is called.                              |  
|     2 | Initialization | _int          | The _init method is called after _create when the widget is first applied to its elements. |  
|     3 | Destruction    | destroy       | The widget's destroy method is used to detach a widget from an element.                    |  
+-------+----------------+---------------+--------------------------------------------------------------------------------------------+

NOTE: The method names starting with an underscore are meant to be private by convention.

So there is a difference between _create and _init. One is used for creation and the other is used for initialization. Every time you call the widget with no arguments or with options, it will indirectly call _init method. Therefore, this can be used to reset (re-initialize) a widget or pass it different options.

More details about each phase here.

jquery widget, _create or _init

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