Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On 9 February 2010 22:25, wrote: > On Tue, 9 Feb 2010 16:09:05 +, rquadl...@googlemail.com (Richard > Quadling) wrote: > >>On 9 February 2010 14:20, Ashley Sheridan wrote: >>> >>> On Tue, 2010-02-09 at 09:19 -0500, Robert Cummings wrote: >>> >>> Richard wrote: >>> > Hi, >>> > >>> >> I have extended the standard exception class to send me an email >>> >> whenever an exception occurs. >>> > >>> > I did that once. Once being the operative word... :-) Ended up with >>> > tens of thousands of emails one morning. At first I thought... "Wow, >>> > maybe my popularity has grown somewhat". But it hadn't. >>> >>> I have something similar... a cron job that checks the error_log file >>> every 10 minutes and sends me the contents if any exist. I also set a >>> special header so I can be sure it's not spam and appropriately route it >>> into my mail folder maze, Much less spammy :) >>> >>> Cheers, >>> Rob. >>> -- >>> http://www.interjinn.com >>> Application and Templating Framework for PHP >>> >>> >>> Real developers don't have errors in their code; they're undocumented >>> features ;) >>> >>> Thanks, >>> Ash >>> http://www.ashleysheridan.co.uk >>> >>> >> >>So, no documentation AND bugs!!! Gee. I really wouldn't want to rely >>on that code base! > > So you don't use (or work with) any Microsoft product? > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > The closest I get is MSSQL which has BOL (Books OnLine). Its enough. Occasionally MS Excel VBA which is fairly well documented and always accessible via a COM interface (so self documenting more or less). But point taken. And only 12 MS critical updates today! Woo Hoo! -- - Richard Quadling "Standing on the shoulders of some very clever giants!" EE : http://www.experts-exchange.com/M_248814.html EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731 ZOPA : http://uk.zopa.com/member/RQuadling -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On Wed, Feb 10, 2010 at 3:04 AM, Paul M Foster wrote:
> $d = funcD($q);
> // tests if necessary
> $c = funcC($p);
> // tests if necessary
> $b = funcB($c);
> // tests if necessary
> $r = funcA($b, $d);
>
You're right.
I knew when i was posting my last reply yesterday that i had made
things probably too complicated.
But after sleeping and a look at real code which is to work with my
improved-err-handling, i've come up with a new construct, that i think
will fit the bill for now.
I'm going to use the "result meta-array" instead of "plain result
values", because that
- completely equalizes the syntax for detecting bad results, and
prevents doing a lookup with a function to a value that is also the
"bad-result" return value for the lookup function.
- is much easier to read, than checking what the "bad-result" value is
for a lookup function.
- allows me to redirect the error info from a called function inside
the calling function
- allows infinite expansion of (meta-)communication between calling
and called functions.
So while i'm dumping the funcA (defaults($onError_pValue), $p) crap,
i'm retaining most of the other ideas in my previous post to this
thread.
the calling function does this, inside 3x foreach:
// if not done yet, resolve the fields
for this table=>hit that
require looking-up
if
(!$sqls[$tableName]['hasPreInserts']) {
foreach
($tableCmd['preInsertFields'] as $fieldName=>$fieldLookupCmd) {
$r =
maintenance__lookupPreInserts ($wm, $fieldLookupCmd);
if (!good($r)) {
$tableCmd['invalidPreInserts'] = true;
} else {
$sqls[$tableName]['preInserts'][$fieldName] = result($r);
}
}
}
if
(!array_key_exists('invalidPreInserts', $tableCmd)) {
// add the fields for this table for
this hit:
.
and the helper functions:
function maintenance__lookupPreInserts (&$wm, $fieldLookupCmd) {
startErrorContext(); // to catch php E_NOTICE, E_WARNING, etc
$flcp = explode ('::', $fieldLookupCmd);
if (count($flcp)!=3) {
return badResult(E_USER_ERROR, array(
'msg' => 'Need 3 counts of \'::\'',
'vars' => array (0=>array('$fieldLookupCmd',
$fieldLookupCmd))
));
}
$section = $flcp[0];
$searchInSection = array();
$criteria = explode (',,', $flcp[1]);
foreach ($criteria as $idx1 => $criterium) {
$cs = explode('===',$flcp[1]);
if (count($cs)!=2) return badResult (E_USER_ERROR, array(
'msg' =>
'Any criterium (after first "::",
between ",,") needs to be like
this:'."\n".
'fieldName===searchValue',
'vars' => array (0=>array('$fieldLookupCmd',
$fieldLookupCmd))
));
$searchInSection = array_merge ($searchInSection, array(
$cs[0] => $cs[1]
));
}
$pathInSection = explode(',,', $flcp[2]);
foreach ($wm[$section] as $idx => $fields) {
$gotIt = true;
foreach ($searchInSection as $fn => $fv) {
if ($fields[$fn]!=$fv) {
$gotIt = false;
break;
}
}
if ($gotIt) {
return chase ($wm[$section], $pathInSection);
}
}
}
function chase ($arr, $indexes) {
startErrorContext();
$r = $arr;
foreach ($indexes as $idx) {
if (is_array($r)) {
$r = $r[$idx];
} else {
return badResult (E_USER_ERROR, array(
'msg' => 'Could not walk the full tree',
'vars' => array(
0=>array('$arr', $arr),
1=>array('$indexes', $indexes)
)
));
}
}
return goodResult($r);
}
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Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On Tue, Feb 09, 2010 at 11:38:42PM +0100, Rene Veerman wrote: > Well, i've thought of a few ways to allow localized overriding of > values returned by functions in case of an error. > > I have yet to figure out what the exact advantages are of this > code-standard, but the overhead seems acceptable and i recon this, > when done, will beat the "trigger_error()-try-catch" paradigm. > I'd like to hear your comments. > > // imo unsafe & prone to fatalities: > $r = funcA ( funcB ( funcC ($p) ), funcD ($q) ); I wasn't going to comment, but seriously, Rene, I would not make it a habit of calling functions within the parameters of other functions. Among other things, it obviously creates a whole host of the problems you're talking about, and it makes your code hard to debug and read. The only way I'd normally do something like this is if I were using native PHP functions and the possible failure of the functions wouldn't matter. Rather, I'd do something like this: $d = funcD($q); // tests if necessary $c = funcC($p); // tests if necessary $b = funcB($c); // tests if necessary $r = funcA($b, $d); Paul -- Paul M. Foster -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Well, i've thought of a few ways to allow localized overriding of
values returned by functions in case of an error.
I have yet to figure out what the exact advantages are of this
code-standard, but the overhead seems acceptable and i recon this,
when done, will beat the "trigger_error()-try-catch" paradigm.
I'd like to hear your comments.
// imo unsafe & prone to fatalities:
$r = funcA ( funcB ( funcC ($p) ), funcD ($q) );
// "safe"; make all notices, warnings and errors from any level
// in the call-chain fully visible, identifiable, and "survivable/fudgeable"
// by code at (all) higher levels in the call-chain.
// [disclaimer] the code below here doesn't pass 3rd-level (funcC())
// (meta-)results back to the first level (funcA()) yet, but this code
// is a start towards that;
$r = funcA (defaults(array(0=>'[funcB failed]',1=>'funcD failed'))),
funcB (defaults($onError_cCallvalue),
funcC (defaults($onError_pValue), $p)
),
funcD (defaults($onError_qValue), $q)
);
function funcA ($defaults, $returnedByFuncB, $returnedByFuncD) {
$returnedByFuncB = workWith ($defaults, $returnedByFuncB, 0);
$returnedByFuncD = workWith ($defaults, $returnedByFuncD, 1);
//all parameters (with idx>0) are meta-arrays containing the
"parameter-value" and all meta-info.
// workWith() always returns the actual parameter-value in
$p['workValue'];
//if any parameter $p (with idx>0) is not a meta-array,
// workWith($d, $r, $n) turns it into a meta array(
// 'workValue' => $p
// );
//if a param is a meta-array $p, and it contains an ['errors'] subarray,
// workWith() sets by-reference $p['workValue'] to one of these
(order of trying):
// $defaults['onError'][$n] (localized override)
// $p['onErrorDefault'], (functions own default value for
when an
error occurs)
//first call to workWith(,,0) will call beginErrorContext()
//beginErrorContext() will increase a global idx $callID (int),
// used to list all notices, warnings and errors, and their details in
// the global variable $callsErrors[$callID][$errorIdx++] = array(
// 'errorMsg' => 'for coders'
// (optional:)'userErrorMsg' => 'for laymen'
// 'backtrace' => array()
// )
// the never-fatal error handler specified with set_error_handler() will
// call getDebugInfo() and append full error info into
// $callsErrors[$callID][$errorIdx++]
//forwardDefaults() clones all meta-details for
// re-used parameters into a new $defaults array to be used
// by funcE().
//the 2nd parameter for forwardDefaults lists which parameter
// passed deeper refers to which parameter received by this here
function.
//the 3rd parameter for forwardDefaults is used to specify new defaults.
$returnedByFuncF = funcF('blablasetting');
$x = funcE (
forwardDefaults($defaults, array(0=>0,2=>1), array(1 =>
'defaultblabla')),
$returnedByFuncB, $returnedByFuncF, $returnedByFuncD
);
return goodResult($x);
}
function funcE ($defaults, $returnedByFuncB, $returnedByFuncF,
$returnedByFuncD) {
$returnedByFuncB = workWith ($defaults, $returnedByFuncB, 0);
$returnedByFuncF = workWith ($defaults, $returnedByFuncF, 2);
$returnedByFuncD = workWith ($defaults, $returnedByFuncD, 2);
// do a call that might raise E_WARNINGS or other crap;
// safeCall() is only a try-except struct to call in this case
// str_replace('xx','yy', ...) and if it fails,
// return the default instead of the actual result.
$x = safeCall (
defaults('returnedByFuncB not a string'),
'str_replace', 'xx','yy',$returnedByFuncB
);
if (is_string($returnedByFuncB) && is_string($returnedByFuncD)) {
return goodResult (
$returnedByFuncB . $returnedByFuncD . $x
);
// goodResult() and badResult() will both call
// endErrorContext(), and copy the errors in
// $callsErrors[$callID]
// to the array returned to the calling function.
// goodResult() and badResult() will call processErrors(),
// which is repsonsible for mailing / db-storage of any
// notices, warnings, errors, etc.
} else {
// badResult() will call getDebugInfo() to include
// a full trace, superglobals, lotsa details.
return badResult (array(
'errorMsg' => 'params 1 and 2 must be strings'
'onErrorDefault' => ''
));
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On Tue, 9 Feb 2010 16:09:05 +, rquadl...@googlemail.com (Richard Quadling) wrote: >On 9 February 2010 14:20, Ashley Sheridan wrote: >> >> On Tue, 2010-02-09 at 09:19 -0500, Robert Cummings wrote: >> >> Richard wrote: >> > Hi, >> > >> >> I have extended the standard exception class to send me an email >> >> whenever an exception occurs. >> > >> > I did that once. Once being the operative word... :-) Ended up with >> > tens of thousands of emails one morning. At first I thought... "Wow, >> > maybe my popularity has grown somewhat". But it hadn't. >> >> I have something similar... a cron job that checks the error_log file >> every 10 minutes and sends me the contents if any exist. I also set a >> special header so I can be sure it's not spam and appropriately route it >> into my mail folder maze, Much less spammy :) >> >> Cheers, >> Rob. >> -- >> http://www.interjinn.com >> Application and Templating Framework for PHP >> >> >> Real developers don't have errors in their code; they're undocumented >> features ;) >> >> Thanks, >> Ash >> http://www.ashleysheridan.co.uk >> >> > >So, no documentation AND bugs!!! Gee. I really wouldn't want to rely >on that code base! So you don't use (or work with) any Microsoft product? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Hi, >> Real developers don't have errors in their code; they're undocumented >> features ;) Or alternatively, if you freelance - "Forthcoming employment opportunities" :-) -- Richard Heyes HTML5 canvas graphing: RGraph - http://www.rgraph.net (updated 7th February) Lots of PHP and Javascript code - http://www.phpguru.org -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On 9 February 2010 14:20, Ashley Sheridan wrote: > > On Tue, 2010-02-09 at 09:19 -0500, Robert Cummings wrote: > > Richard wrote: > > Hi, > > > >> I have extended the standard exception class to send me an email > >> whenever an exception occurs. > > > > I did that once. Once being the operative word... :-) Ended up with > > tens of thousands of emails one morning. At first I thought... "Wow, > > maybe my popularity has grown somewhat". But it hadn't. > > I have something similar... a cron job that checks the error_log file > every 10 minutes and sends me the contents if any exist. I also set a > special header so I can be sure it's not spam and appropriately route it > into my mail folder maze, Much less spammy :) > > Cheers, > Rob. > -- > http://www.interjinn.com > Application and Templating Framework for PHP > > > Real developers don't have errors in their code; they're undocumented > features ;) > > Thanks, > Ash > http://www.ashleysheridan.co.uk > > So, no documentation AND bugs!!! Gee. I really wouldn't want to rely on that code base! -- - Richard Quadling "Standing on the shoulders of some very clever giants!" EE : http://www.experts-exchange.com/M_248814.html EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731 ZOPA : http://uk.zopa.com/member/RQuadling -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Ashley Sheridan wrote: On Tue, 2010-02-09 at 09:19 -0500, Robert Cummings wrote: Richard wrote: Hi, I have extended the standard exception class to send me an email whenever an exception occurs. I did that once. Once being the operative word... :-) Ended up with tens of thousands of emails one morning. At first I thought... "Wow, maybe my popularity has grown somewhat". But it hadn't. I have something similar... a cron job that checks the error_log file every 10 minutes and sends me the contents if any exist. I also set a special header so I can be sure it's not spam and appropriately route it into my mail folder maze, Much less spammy :) Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP Real developers don't have errors in their code; they're undocumented features ;) H... I've always gone with "a wise man learns from his mistakes". Not that I'm saying I'm wise or anything... just seems a good goal to shoot for :) Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On Tue, 2010-02-09 at 09:19 -0500, Robert Cummings wrote: > Richard wrote: > > Hi, > > > >> I have extended the standard exception class to send me an email > >> whenever an exception occurs. > > > > I did that once. Once being the operative word... :-) Ended up with > > tens of thousands of emails one morning. At first I thought... "Wow, > > maybe my popularity has grown somewhat". But it hadn't. > > I have something similar... a cron job that checks the error_log file > every 10 minutes and sends me the contents if any exist. I also set a > special header so I can be sure it's not spam and appropriately route it > into my mail folder maze, Much less spammy :) > > Cheers, > Rob. > -- > http://www.interjinn.com > Application and Templating Framework for PHP > Real developers don't have errors in their code; they're undocumented features ;) Thanks, Ash http://www.ashleysheridan.co.uk
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Richard wrote: Hi, I have extended the standard exception class to send me an email whenever an exception occurs. I did that once. Once being the operative word... :-) Ended up with tens of thousands of emails one morning. At first I thought... "Wow, maybe my popularity has grown somewhat". But it hadn't. I have something similar... a cron job that checks the error_log file every 10 minutes and sends me the contents if any exist. I also set a special header so I can be sure it's not spam and appropriately route it into my mail folder maze, Much less spammy :) Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Hi, > But I bet you REALLY quickly fixed the problem! I just took out the error handling. :-) -- Richard Heyes HTML5 canvas graphing: RGraph - http://www.rgraph.net (updated 7th February) Lots of PHP and Javascript code - http://www.phpguru.org -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On 9 February 2010 12:55, Richard wrote: > Hi, > >> I have extended the standard exception class to send me an email >> whenever an exception occurs. > > I did that once. Once being the operative word... :-) Ended up with > tens of thousands of emails one morning. At first I thought... "Wow, > maybe my popularity has grown somewhat". But it hadn't. > > -- > Richard Heyes > HTML5 canvas graphing: RGraph - http://www.rgraph.net (updated 31st January) > Lots of PHP and Javascript code - http://www.phpguru.org > But I bet you REALLY quickly fixed the problem! Oh. BTW. Thanks for RMail (previously known as htmlmimemail5 if anyone else is interested). -- - Richard Quadling "Standing on the shoulders of some very clever giants!" EE : http://www.experts-exchange.com/M_248814.html EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731 ZOPA : http://uk.zopa.com/member/RQuadling -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
Hi, > I have extended the standard exception class to send me an email > whenever an exception occurs. I did that once. Once being the operative word... :-) Ended up with tens of thousands of emails one morning. At first I thought... "Wow, maybe my popularity has grown somewhat". But it hadn't. -- Richard Heyes HTML5 canvas graphing: RGraph - http://www.rgraph.net (updated 31st January) Lots of PHP and Javascript code - http://www.phpguru.org -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On 9 February 2010 11:48, Nathan Rixham wrote:
> Rene Veerman wrote:
>> Hi,
>>
>> I'm looking for a strategy to do informative error handling at all
>> levels of my code, yet keep these errors non-fatal as often as
>> possible.
>
> error_log - for logging errors
> throw Exception - for show stoppers
> try/catch - for when you can handle a potential show stopper
>
> custom error logging / messaging can easily be achieved with something
> like this:
>
>
> class Messenger
> {
>
> private static $_messages = array();
>
> public static function addMessage( $string )
> {
> self::$_messages[] = $string;
> if( $string instanceof Exception ) {
> echo self::report();
> }
> }
>
> public static function report()
> {
> return implode( PHP_EOL , self::$_messages );
> }
>
> }
>
> set_exception_handler( 'Messenger::addMessage' );
>
> Messenger::addMessage( 'little error report 1' );
> Messenger::addMessage( 'little error report 2' );
> Messenger::addMessage( 'little error report 3' );
> throw new Exception( 'this will stop the script' );
> // exception will kill the script; if you comment it out
> // or wrap it in a try catch then you can keep going..
> Messenger::addMessage( 'little error report 4' );
> // try catch exceptions and report them like this..
> try {
> throw new Exception( 'we could catch this' );
> } catch ( Exception $e ) {
> Messenger::addMessage( $e );
> }
> Messenger::addMessage( 'little error report 5' );
> // and when your done just echo it out or save it or..
> echo Messenger::report();
>
>
> Regards!
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>
I have extended the standard exception class to send me an email
whenever an exception occurs.
I treat all errors on the live system as exceptions. They shouldn't
occur. If they do, I've missed something.
But at least I'll get a near instant notification of the issue, along
with the stack and all the params involved.
Very useful.
--
-
Richard Quadling
"Standing on the shoulders of some very clever giants!"
EE : http://www.experts-exchange.com/M_248814.html
EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp
Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
ZOPA : http://uk.zopa.com/member/RQuadling
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Re: [PHP] Re: poll: howto do informative error handling without the fatalities
On Tue, 2010-02-09 at 07:22 +0100, Rene Veerman wrote: > I would also like to hear suggestions on how to fix this mess: > > $r = funcA ( funcB ( funcC ( $p ) ) ); > > if funcB() / funcC() fails, how would you fudge/abort the calling > function in the chain? > One may think that funcA and funcB just check their parameters list > for being "error" arrays, but the problem i foresee is that depending > on the context of the $r= call, desired behaviour may vary at any > stage in the funcA -> funcB -> funcC chain. > I would abort it by embedding the mess in a try.. catch statement, then throwing an exception. Teus. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
