Extending Struts(1)
- 1. Extending Struts Prepared by: Ramez Hassan
- 2. Agenda Struts Overview : Basic review on struts framework. Stating struts main objects. What is a plug-in? ModuleConfig story. Tiles plug-in: Default design procedure. Tiles with struts.
- 3. Struts Overview Struts is a framework that is built on MVC 2 architectural pattern. Struts Flow review. Struts gives extension capabilities to each step.
- 4. Struts Overview Struts Main Objects: ActionServlet. RequestProcessor. ModuleConfig. ActionClass. ActionForm. JSP view.
- 5. What is a plug-in ? A plug-in is a configuration wrapper for a module-specific resource or service that needs to be notified about application startup and shutdown events.
- 6. What is a plug-in ? How to plug in a struts plug-in ?
- 7. What is a plug-in ? How to write a plug-in ?
- 8. What is a plug-in ? What is ModuleConfig ?
- 9. So, A Plug-in is … A useful feature in struts framework that facilitate: Dynamically wrap any resource of struts framework, e.g. RequestProcessor. Initialize any business component for the application, e.g. Hibernate.
- 10. Tiles Plug-in Applying html layout procedures: Default Design procedure was to copy and paste layout to every new page. Altering in design could lead to a resources leak, even though it’s a periodical procedure for any web application.
- 11. Tiles Plug-in Applying html layout procedures (cont.): <jsp:include> allows you to include either a static or dynamic file in a JSP file {every page will use jsp:include}. The problem: when the architecture changes even a small td in a table will lead to alterations in every page in the site.
- 12. Tiles Plug-in Tiles Solution : Applying same mechanism of <jsp:include /> but with defining the layout it self in a separate page. The components in this case will be:
- 13. Tiles Plug-in Tiles Solution (cont.): Each new page in this case will require defining the following : Page body (which the part that changes frequently, 0 to n pages). Page layout (The layout that will be attached when displaying the page). Any dynamic or static content will be referenced in the layout, e.g. header , footer and/or menu. This solution made it much better in changing layout but a little bit difficult in pages maintenance.
- 14. Tiles Plug-in Struts Tiles plug-in Solution: The same as tile solution except adding XML capabilities in definition and Objects relation as well.
- 15. Tiles Plug-in Struts Tiles plug-in Solution (cont.): Struts Tiles demo.
- 16. Tiles Plug-in Struts Tiles demo (cont.): XML Configurations:-
- 17. Tiles Plug-in Struts Tiles demo (cont.): Static Objects tiles_static/header.jsp tiles_static/menu.jsp tiles_static/footer.jsp
- 18. Tiles Plug-in Struts Tiles demo (cont.): Layout Definition Page: tiles_layout/layout_small.jsp
- 19. Tiles Plug-in Struts Tiles demo (cont.): Adding tiles into layout using struts-tiles.tld:
- 20. Tiles Plug-in Struts Tiles demo (cont.): Finally the page to display :- I can write my code in the page /demos/myPage.jsp and don’t worry about layout any more.
- 21. Tiles Plug-in Struts Tiles demo (cont.): How can struts actions interact with tile page:
- 22. Tiles Plug-in Configurations needed :
- 23. Tiles Plug-in How does tiles plug-in work…? Replaces RequestProcessor in startup with TilesRequestProcessor. TilesRequestProcessor class overrides processForwardConfig() to handle any navigation to any tiles definition. In processing a definition, all pages is included using doForward() doInclude() or of RequestProcessor which uses methods of RequestDispatcher.
- 24. Tiles Plug-in Tiles attributes: TileScope is a ComponentContext for tiles components (pages). <tile:useAttribute name=“” id=“” scope=“”/> is used to move attributes from tiles scope to request scope.
- 25. Tiles Plug-in Tiles attributes (cont.): < put:list name=“demoList”> < item value=“link1" link="/li1.do" /> < item value=“link2" link="/li2.do" /> < item value=“link2" link="/li3.do" /> </ put:list > Values can be retrieved and used as List in any scope.
- 26. Questions ?
- 27. Thank You