Automatic Conditional Branching

Question

This is what I need to do. I set a hidden parameter on a page with an onload process. If that parameter is a certain value, I need the page to automatically branch to a different page. Using data that has been loaded on the first page. Any ideas on how to implement this?

Answer 1

Your first example mentions a "onload process".
There are 6 types of onload firing points.
On Load - Before Header
On Load - After Header
On Load - Before Regions
On Load - After Regions
On Load - Before Footer
On Load - After Footer
Which one are you referring to?
I was playing with this at
http://htmldb.oracle.com/pls/otn/f?p=24317:52
The page has a onload process that redirects to Yahoo if the textbox has a value "yahoo" in session state.
I found that "On Load - Before Header" always redirects without needing the htp.init. All other firing points just dump the Location: header on the page, presumably because the header has already been closed (as you explained). Putting the htp.init before the redirect makes the page redirect regardless of the firing point.
Questions:
1. Does the word "header" in the 6 firing points above refer to HTTP headers? Somehow, since it also mentions footers in the list, I assumed that it refered to the HTML DB page header/footer. But based on the behaviour I observed above, it does seem to be refering to the HTTP headers. Can you confirm that?
2. Since htp.init always makes the redirect "work" (its sort of like a "force redirect"), why not always put a call to htp.init before the redirect? This will make the redirect work regardless of anything else.
One could even do owa_util.redirect(p_url,bclose_header=>false) to not close the HTTP header so as not to mess up any cookie or other http header-specific stuff that the target page might be doing.
3. On a kind of related note, what are the practical uses of all the various onload process firing points above? When would such a granular level of control be needed?
Thanks