Forum OpenACS Q&A: Defining ad_procs within a script?

Posted by Jade Rubick on 03/21/02 12:57 AM

On an ACS 3.4.10 installation...

Is it bad to use ad_proc within a normally executed .tcl page? I
define an ad_proc that is used by a procedure within just that page.

2: Response to Defining ad_procs within a script? (response to 1)

Posted by Don Baccus on 03/21/02 03:23 AM

Hmmm...it will probably be recompiled each time the script's run, rather than just once when it's loaded as would be the case if it were in the library.

I'm not sure, though. There's a Rob Mayoff hack in AOLserver 3.3+ad13 that save compiled bytes for the top-level script itself, but I think embedded procs may get recompiled (because "proc" itself is just a command, after all).

Does anyone know?

3: Response to Defining ad_procs within a script? (response to 1)

Posted by Carl Coryell-Martin on 03/21/02 07:04 AM

There is another issue if you are using the ATS. In some contexts pages are run in the template namespace and a proc will be defined in that space and hang around in the thread. I read in some of the docs for the ATS that defining procs in .tcl pages was not reccommended.

cheers,

4: Response to Defining ad_procs within a script? (response to 1)

Posted by Tom Jackson on 03/21/02 10:57 AM

You can do this for testing purposes, but once the proc works you should move it out of the page. Once defined, the proc probably will remain in the thread's interp, so as long as that interp remains alive, the proc you define in one page will be there if the same thread processes a different request. So it would be bad if this proc was overwriting a proc that was defined at startup, if the proc was used on more than the one page you redefine it on.

5: Response to Defining ad_procs within a script? (response to 1)

Posted by David Walker on 03/21/02 12:28 PM

If you're just looking to reuse a piece of code in a bunch of different places you could also use a tcl string for that as shown below

set code_to_reuse {
 ns_write $var1
 ns_write $var2
}

set var1 xxx
set var2 yyy
eval $code_to_reuse
set var1 123
set var2 456
eval $code_to_reuse