HomeOracle Page 4 - Adding Processes to HTML DB Applications
Reset Pagination - Oracle
In this second part of a three-part series covering HTML DB applications, you will learn about processes. This article is excerpted from chapter 13 of the Oracle HTML DB Handbook, written by Lawrence Linnemeyer and Bradley Brown (McGraw-Hill, 2006; ISBN: 0072257687).
The Reset Pagination process does one and only one thing—it resets the pagination for the current page. After selecting the Reset Pagination type option in the Create Page Process Wizard, the only information you must provide is a name, sequence, processing point, and any conditions.
On Demand
On Demand processes allow you to write a single process that can be evaluated on multiple pages at different points. There are two parts to On Demand processes: the definition of an application-level On Demand process and page-level definitions of On Demand processes that call the application-level process. Like all application-level processes, an On Demand process is a PL/SQL type process.
If you have a process that needs to be evaluated at the same evaluation point on multiple pages, create an application-level process and limit its evaluation to the appropriate pages with the process’s Condition section. However, if you need the same process to be evaluated by multiple pages at different points, you will want to create an application-level On Demand process and page-level On Demand processes on the appropriate pages for evaluation at the appropriate points.
Session State
Session State processes allow you to clear out the session state. Normally this type of process is used to clear out the cached values for the current session of the current user. You can clear out individual items by listing those items. You can clear out all items on individual pages by listing the pages, or you can clear out everything for the current session of the current user.
In addition to clearing items for the current session, this type process can also deal with the current user’s preferences. Remember, preferences are values stored per user, so the next time the user returns, in a different session, the values are still available. With a Session State process, you can clear all the preferences for the current user or you can set the value of a certain preference based on the value of an item.
Finally, Session State processes can be used for managing sessions within the workspace. This is part of the administrative portion of an application. Remember, session states are stored in the database, and they don’t go away until they are removed either through the Workspace Administration section available in the HTML DB development environment or through the HTML DB Administrator interface. The options available for this purpose are Remove All Session State for the Current Application and Remove All Session State for a List of Applications Within the Workspace.
Please check back next week for the conclusion to this article.