SMF PHP error... Am I missing something subtle in the PHP languagesyntax?

[William Krick]

Given these two code snippets, the first generates errors, the second
doesn't...

// generates errors
$tboard = $context['linktree'][2]['name'];
$tboard = empty($tboard)? '':' - '.$tboard;
$ttopic = $context['linktree'][3]['name'];
$ttopic = empty($ttopic)? '':' - '.$ttopic;
if (! ereg($context['forum_name'], $context['page_title']))
$context['page_title'] = $context['linktree'][0]['name'].$tboard.
$ttopic;

// no errors
$tboard = empty($context['linktree'][2]['name'])?'':' - '.
$context['linktree'][2]['name'];
$ttopic = empty($context['linktree'][3]['name'])?'':' - '.
$context['linktree'][3]['name'];
if (! ereg($context['forum_name'], $context['page_title']))
$context['page_title'] = $context['linktree'][0]['name'].$tboard.
$ttopic;


Here's a few sample errors that I see in my SMF log only when using
the first version of the code. I think the "2" and "3" referred to
are the subscripts in the code snippet...


8: Undefined offset: 3
File: /home/xxxxxx/public_html/forums/Themes/default/
Admin.template. php (main_above sub template - eval?)
Line: 66

8: Undefined offset: 2
File: /home/xxxxxx/public_html/forums/Themes/default/
Admin.template. php (main_above sub template - eval?)
Line: 64


For the life of me, I cannot figure out the first block of code
generates errors. Am I missing something subtle about the PHP syntax?

[=?iso-8859-1?Q?=C1lvaro?= G. Vicario]

Re: SMF PHP error... Am I missing something subtle in the PHP language syntax?

*** William Krick escribió/wrote (Mon, 29 Sep 2008 11:49:14 -0700 (PDT)):

// generates errors
$tboard = $context['linktree'][2]['name'];
$tboard = empty($tboard)? '':' - '.$tboard;

// no errors
$tboard = empty($context['linktree'][2]['name'])?'':' - '.
$context['linktree'][2]['name'];

The key point is that empty($foo) does not trigger a notice when $foo is
not set.

--
-- http://alvaro.es - Álvaro G. Vicario - Burgos, Spain
-- Mi sitio sobre programación web: http://bits.demogracia.com
-- Mi web de humor en cubitos: http://www.demogracia.com
--

[William Krick]

Re: SMF PHP error... Am I missing something subtle in the PHPlanguage syntax?

On Sep 29, 3:42 pm, "Álvaro G. Vicario"
<webmasterNOSPA MTHA...@demogra cia.comwrote:

*** William Krick escribió/wrote (Mon, 29 Sep 2008 11:49:14 -0700 (PDT)):
>

// generates errors
$tboard = $context['linktree'][2]['name'];
$tboard = empty($tboard)? '':' - '.$tboard;
// no errors
$tboard = empty($context['linktree'][2]['name'])?'':' - '.
$context['linktree'][2]['name'];

>
The key point is that empty($foo) does not trigger a notice when $foo is
not set.
>

Doesn't the first line in the example guarantee that $tboard is set,
even if to null or an empty string?

Basically, I just want to alias $context['linktree'][2]['name']
to a variable so that the code is clearer and easier to follow.
The only snag is that $context['linktree'][2]['name']
may sometimes be blank.

This shouldn't be this difficult to do.

[Tim Roberts]

Re: SMF PHP error... Am I missing something subtle in the PHP language syntax?

William Krick <wkrick@gmail.c omwrote:

>On Sep 29, 3:42 pm, "Álvaro G. Vicario"
><webmasterNOSP AMTHA...@demogr acia.comwrote:

>*** William Krick escribió/wrote (Mon, 29 Sep 2008 11:49:14 -0700 (PDT)):
>>

// generates errors
$tboard = $context['linktree'][2]['name'];
$tboard = empty($tboard)? '':' - '.$tboard;
// no errors
$tboard = empty($context['linktree'][2]['name'])?'':' - '.
$context['linktree'][2]['name'];

>>
>The key point is that empty($foo) does not trigger a notice when $foo is
>not set.
>>

>
>Doesn't the first line in the example guarantee that $tboard is set,
>even if to null or an empty string?

Yes, but you'll get a warning in the first case if $context['linktree']
does not contain [2]. The "empty" function suppresses that warning.

>Basically, I just want to alias $context['linktree'][2]['name']
>to a variable so that the code is clearer and easier to follow.
>The only snag is that $context['linktree'][2]['name']
>may sometimes be blank.

....or missing, apparently. That's the problem.
--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

[William Krick]

Re: SMF PHP error... Am I missing something subtle in the PHPlanguage syntax?

On Oct 5, 12:52 am, Tim Roberts <t...@probo.com wrote:

William  Krick <wkr...@gmail.c omwrote:
>

On Sep 29, 3:42 pm, "Álvaro G. Vicario"
<webmasterNOSPA MTHA...@demogra cia.comwrote:

*** William Krick escribió/wrote (Mon, 29 Sep 2008 11:49:14 -0700 (PDT)):

>

// generates errors
$tboard = $context['linktree'][2]['name'];
$tboard = empty($tboard)? '':' - '.$tboard;
// no errors
$tboard = empty($context['linktree'][2]['name'])?'':' - '.
$context['linktree'][2]['name'];

>

The key point is that empty($foo) does not trigger a notice when $foo is
not set.

>

Doesn't the first line in the example guarantee that $tboard is set,
even if to null or an empty string?

>
Yes, but you'll get a warning in the first case if $context['linktree']
does not contain [2].  The "empty" function suppresses that warning.
>

Basically, I just want to alias  $context['linktree'][2]['name']
to a variable so that the code is clearer and easier to follow.
The only snag is that  $context['linktree'][2]['name']
may sometimes be blank.

>
...or missing, apparently.  That's the problem.

Hmm... so then the second example might not be doing what I want, even
if there is no error.

Any suggestions on the "right" way to do what I'm trying to do?

Do I need to first test using isset(), then empty(), or possibly try
to determine the length of $context['linktree'] before taking any
action?

Essentially, there are potentially 4 items in the linktree...

$a = $context['linktree'][0]['name']
$b = $context['linktree'][1]['name']
$c = $context['linktree'][2]['name']
$d = $context['linktree'][3]['name']

....the presence of each item depends on the one before it, so if $c is
present, $a and $b will also be present. I want is this...

$context['page_title'] = $a.' - '.$c.' - '.$d; (if all three are
present)
$context['page_title'] = $a.' - '.$c.'; (if two are present)
$context['page_title'] = $a.'; (if one is present)

....I only want the dashes to show up if the next item exists,
otherwise, I end up with a lot of extra dashes at the end of the page
title when I'm further up the tree. Hence my original logic with
empty().

Any suggestions are appreciated.