Chapter 4. Ext Plugin and Hooks

Ext plugin is a powerful tool to extend the Liferay portal core. There are almost no limits to what can be customized. Thus, the Ext plugin has to be used carefully. Ext plugin is designed to be used only in special scenarios where all other plugin types such as portlets, hooks, themes, layout templates, and webs cannot meet the needs.

Hooks can fill a wide variety of common needs for overriding the portal core functionality. Whenever possible, hooks should be used in place of the Ext plugin, as hooks are hot deployable and more forward compatible. There are common scenarios which require the use of a hook, for example, performing custom actions on portal startup or user login, overwriting or extending portal JSPs, modifying portal properties, replacing a portal service with custom implementation, modifying indexer post processors, and updating struts actions, servlet filters, and servlet filters mappings.

This chapter will first introduce the Ext plugin...