Error Context Display

In some cases, you may want to customize error generation. For instance, for each error (basic/exception), it is useful to include file, line number, and class/function context information in order to trace it. The default option will be sufficient for most cases but you want perhaps customize the rendering of context information.

With this example we will change display and log renders.

<?php
require_once 'HTML/Progress2.php';
$displayConfig = array(
'lineFormat' => '%1$s: %2$s %3$s',
'contextFormat' => 'File: %1$s '
. 'Line: %2$s '
. 'Function: %3$s '
);
$logConfig = array(
'lineFormat' => '%1$s %2$s [%3$s] %4$s',
'timeFormat' => '%b'
);
$prefs = array(
'handler' => array('display' => $displayConfig,
'log' => $logConfig
));
$meter = new HTML_Progress2($prefs);
// ...
$result = $meter->setValue('37');
?>

Display render will give something like:

Exception: invalid input, parameter #1 "$val" was expecting "integer", instead got "string"
File: [path_to]\[filename] 
Line: 23 
Function: html_progress2->setvalue

	error level
	message body with context informations
	call context (file, line, function)

Log render will give something like:

Aug 127.0.0.1 [exception] invalid input, parameter #1 "$val" was expecting "integer", instead got "string"

	client ip address and execution date
	error level
	message body with context informations

	Note
	To have both display and log output, check the `php.ini`display_errors and log_errors values : must be set to `TRUE`.

Let rewiew, step by step, how to get such results.

Remember that with default classes, there are two drivers : display and log that have both their own configuration parameters. You can override these parameters values with the handler entry in the hash of first argument of the HTML_Progress2 class constructor.

We did it here with the $prefs variable; its a two keys associative array. First key display defines the display driver values, and the second key log defines the log driver values.

Review the display driver custom values. Only two keys: lineFormat, contextFormat are redefined, thats means remains key eol keep its default value. See table below.

Table 16.2. Display driver configuration parameters

Parameter	Type	Default	Description
eol	string	<br />\n	The end-on-line character sequence
lineFormat	string	<b>%1$s</b>: %2$s %3$s	Log line format specification: 1$ = error level 2$ = error message (body) 3$ = error context
contextFormat	string	in <b>%3$s</b> (file <b>%1$s</b> on line <b>%2$s</b>)	Context format (class, file, line) specification: 1$ = script file name 2$ = line in script file 3$ = class/method names

	Tip
	If you don't wish to see context information in the error message, then remove the parameter %3$ in the lineFormat option even if contextFormat is set.

Review now the log driver custom values. Only two keys lineFormat, timeFormat are redefined, thats means six remains keys eol, contextFormat, ident, message_type, destination, extra_headers keep their default values. See table below.

Table 16.3. Log driver configuration parameters

Parameter	Type	Default	Description
eol	string	\n	The end-on-line character sequence
lineFormat	string	%1$s %2$s [%3$s] %4$s %5$s	Log line format specification: $1 = time error 2$ = ident (client ip) 3$ = error level 4$ = error message (body) 5$ = error context
contextFormat	string	in %3$s (file %1$s on line %2$s)	Context format (class, file, line) specification: 1$ = script file name 2$ = line in script file 3$ = class/method names
timeFormat	string	%b %d %H:%M:%S	Time stamp format used by strftime
ident	string	REMOTE_ADDR	Client IP
message_type	string	3	Destination type used by error_log
destination	string	html_progress2_error.log	Destination name used by error_log
extra_headers	string	`NULL`	Extra headers depending of destination type

	Tip
	If you don't wish to see context information in the error message, then remove the parameter %5$ in the lineFormat option even if contextFormat is set.

Prev	Up	Next
Controlling error generation	Home	Custom Error Message Generation

HTML_Progress2 : The Definitive Guide

Error Context Display