php debugging: how to debug SMF and/or your mods ?

[aegersz]

i'm having trouble with a mod that works but not properly. it throws no errors.
hi guys, i'd like your help with this please. i have used some basic php debugging techniques like echo'<pre>';var_dump($var);die; and have used debug_print_backtrace(); and have configured php.ini to log etc.

all the variables i inspected seem correct ... so i ask these 3 questions.

1. what do you guys use to debug your mods OR even SMF itself ?

2. ideally, i'd like to step through the code line-by-line and inspect everything after each statment - is that sort of debugger available and free ? OR are there other ways to achieve almost the same thing ?

3. do all php debugging tools run on the server (i guess most would) ?

[Arantor]

I used the var_dump method even when developing 2.1 itself.

[aegersz]

ok then but how do i go about seeing the results from a SQL call like $request = $smcFunc['db_query'] ... etc. ?

i'd like to see what data the query returns, assuming that it executes without error; i'm struggling to see how and where the returned data is processed further after the query finishes.

[Arantor]

It's processed by calls to db_fetch_row and db_fetch_assoc, MySQL results are handled one row at a time.

[aegersz]

got it but have hit a wall because all my checks show the results that i would expect.

thanks for your help ... i will wait for the mod author to check his code then - he expects multiple rows to return from his query but he only gets 1 back - so he needs to rework his SQL, i can only assume.

but i learned something so it was worthwhile

[4Kstore]

Also you can try this: http://custom.simplemachines.org/mods/index.php?mod=3481

[aegersz]

thanks; i have debugging on always in my test system, I check my logs often and my live system has a tiny load.

but I can't resist another handy mod !

[Pipke]

Edit Settings.php and add to the end (before ?>)
$db_show_debug = true;

[aegersz]

I use http://custom.simplemachines.org/mods/index.php?mod=1466 to change that setting plus it shows a bunch of information at the bottom of the page.

[aegersz]

Also you can try this: http://custom.simplemachines.org/mods/index.php?mod=3481

i like this mod as i can also see the SQL statements being used.

thank you !

[4Kstore]

Yes, it great for debug and improve the performance

[Arantor]

All that mod does is enable a feature already in SMF, you could enable it with a single line of code in Settings.php, but yes, that one really helps.

[albertlast]

The best way in my eyes to use xdebug,
than you can use the debug tool of your ide.

you can stop on specific line look at vars and many more things.