Web Browser Caching

Use

At runtime, the Internet Transaction Server (ITS) executes Web transactions and merges the field contents of every SAP system screen into a corresponding HTML template. The expanded HTML source is then sent to a Web browser.

Process

In the Web browser, the user can navigate between Web pages by using either the Back and Forward buttons, or the History function. The expiration date of the Web page determines whether the page can be taken from the browser cache or whether it must be regenerated by making a request to the Web server.

HTML pages are available in the browser cache if they were initially generated with a POST operation, and their expiration date is recent enough, as shown in the following graphic:

The process runs as follows:

  1. The user navigates from page 1 to page 2 by pressing a button in page 1. The button issues a POST operation to request generation of page 2.

  2. The Web browser does not have page 2 in its browser cache and therefore requests the page from the Internet Communication Framework.

  3. The ICM forwards the request to the ITS.

  4. The ITS generates the HTML page and sends it back to the ICM.

  5. The ICM sends the HTML page to the Web browser.

  6. The Web browser caches the HTML page, and displays it to the user.

  7. In page 2, the user navigates to a third page (by pressing a button) and then back to page 2.

Since the page was originally generated with a POST operation, the Web browser can now redisplay page 2 by removing it from the cache. Another request to the ICM is not necessary.