Programming model guidelines for server-side mode
Learn which widgets use in server-side mode and how to adapt widgets for server-side mode.
Widgets use in server-side mode
In general, all widgets programmed against the iWidget specification can be rendered in server side mode. However, a key difference to client side rendering is that full page refreshes happen frequently and not only if a user action triggers them explicitly. For example, each time a user triggers a portlet action, this results in a full page refresh that fetches the updated page from the server. This also means the document object model (DOM) is regenerated as a result of a standard user interaction. Therefore, to write a widget that works in server side mode, apply the guidelines listed in the following:
- State always needs to be stored using onNavState changed events and not by storing it in the dom. Otherwise it is gone after a page refresh.
Furthermore, some of the predefined events the iWidget specification specifies behave slightly different when we use them in server side rendering mode:
- onRefreshNeeded: This event is not sent after a page refresh.
- onSizeChanged: This event is only sent if the skin used with it supports it.
- onNewWire:
- This event can be sent by a client side user interface component for widgets on the same page.
- This event is not sent if the wire model of the page was changed externally.
- This event is not sent after a page refresh.
- onRemoveWire:
- This event can be sent by a client side user interface component for widgets on the same page.
- This event is not sent if the wire model of the page was changed externally.
- This event is not sent after a page refresh.
Options of interactions between widgets and portlets
- iWidgets cannot:
- Send events to JSR168 or JSR286 portlets.
- Receive events from JSR168 or JSR286 portlets.
- Share render parameters with JSR286 portlets.
- iWidgets can:
- Send events to and receive events from other iWidgets.
- Share render parameters with other iWidgets on the same page using shared item sets.