When the WikiText has been transformed into a parse-tree the next step is to transform this parse-tree into a widget-tree.
We talked about widgets as parts of the WikiText markup but in fact each node of the parse-tree is transformed to a widget object.
The core plug-in provides a basic widget object which gets the parse node it should represent and a DOM node. The widget then must create the DOM structure which represents the parse node and add it to the provided DOM node.
A ~LinkWidget for example would create the DOM node for a ``<a>...</a>`` tag and put it in the provided DOM node.
When a widget gets a parse node with child nodes it must create the corresponding child widgets.
All this functionality is basically provided with the base widget. But when creating the widget for a parse node it loads additional modules with ``module-type: widget``. These modules can export multiple widgets which extend the base widget and can override it's methods like the rendering and refresh functions.
As described in [[Parser]] each parse node contains a "type" property. This type directly determines which widget module is used.
Would be transformed to a [[TextWidget|$:/core/modules/widgets/text.js]].
(Note that the ~TextWidget module exports a property "text".)
So in fact when talking about widgets in WikiText, they are not a feature added to WikiText but the ability to directly use a specific widget instead of the parser choosing a widget type.
In the beginning we talked about widgets and how they enable dynamic behaviour. But up until now we only described how widgets create DOM nodes from parse nodes.
