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www.giggi.me / code-igniter-v3-giggi / 27b5005d23ab2d55e459b59890d0108e100cb070 / . / user_guide / general / errors.html
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4
Derek Allard404e35d2007-08-07 01:00:45 +0000[diff] [blame]5<title>CodeIgniter User Guide : Error Handling</title>
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]6
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Derek Allard3d879d52008-01-18 19:41:32 +0000[diff] [blame]19<meta name='author' content='ExpressionEngine Dev Team' />
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Derek Allard197d10b2008-02-12 04:20:38 +0000[diff] [blame]31<td><h1>CodeIgniter User Guide Version 1.6.1</h1></td>
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Derek Jones7a9193a2008-01-21 18:39:20 +0000[diff] [blame]43<a href="http://codeigniter.com/">CodeIgniter Home</a> &nbsp;&#8250;&nbsp;
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]44<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
45Error Handling
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57
58<h1>Error Handling</h1>
59
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]60<p>CodeIgniter lets you build error reporting into your applications using the functions described below.
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]61In addition, it has an error logging class that permits error and debugging messages to be saved as text files.</p>
62
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]63<p class="important"><strong>Note:</strong> By default, CodeIgniter displays all PHP errors. You might
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]64wish to change this behavior once your development is complete. You'll find the <dfn>error_reporting()</dfn>
65function located at the top of your main index.php file. Disabling error reporting will NOT prevent log files
66from being written if there are errors.</p>
67
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]68<p>Unlike most systems in CodeIgniter, the error functions are simple procedural interfaces that are available
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]69globally throughout the application. This approach permits error messages to get triggered without having to worry
70about class/function scoping.</p>
71
72<p>The following functions let you generate errors:</p>
73
74<h2>show_error('<var>message</var>')</h2>
75<p>This function will display the error message supplied to it using the following error template:</p>
76<p><dfn>application/errors/</dfn><kbd>error_general.php</kbd></p>
77
78<h2>show_404('<var>page</var>')</h2>
79<p>This function will display the 404 error message supplied to it using the following error template:</p>
80<p><dfn>application/errors/</dfn><kbd>error_404.php</kbd></p>
81
82<p>The function expects the string passed to it to be the file path to the page that isn't found.
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]83Note that CodeIgniter automatically shows 404 messages if controllers are not found.</p>
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]84
85
86<h2>log_message('<var>level</var>', '<samp>message</samp>')</h2>
87
admine334c472006-10-21 19:44:22 +0000[diff] [blame]88<p>This function lets you write messages to your log files. You must supply one of three "levels"
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]89in the first parameter, indicating what type of message it is (debug, error, info), with the message
90itself in the second parameter. Example:</p>
91
92<code>
93if ($some_var == "")<br />
94{<br />
95&nbsp;&nbsp;&nbsp;&nbsp;log_message('error', 'Some variable did not contain a value.');<br />
96}<br />
97else<br />
98{<br />
99&nbsp;&nbsp;&nbsp;&nbsp;log_message('debug', 'Some variable was correctly set');<br />
100}<br />
101<br />
102log_message('info', 'The purpose of some variable is to provide some value.');<br />
103</code>
104
105<p>There are three message types:</p>
106
107<ol>
108<li>Error Messages. These are actual errors, such as PHP errors or user errors.</li>
109<li>Debug Messages. These are messages that assist in debugging. For example, if a class has been initialized, you could log this as debugging info.</li>
Derek Allardd2df9bc2007-04-15 17:41:17 +0000[diff] [blame]110<li>Informational Messages. These are the lowest priority messages, simply giving information regarding some process. CodeIgniter doesn't natively generate any info messages but you may want to in your application.</li>
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]111</ol>
112
113
admine334c472006-10-21 19:44:22 +0000[diff] [blame]114<p class="important"><strong>Note:</strong> In order for the log file to actually be written, the
115 "logs" folder must be writable. In addition, you must set the "threshold" for logging.
adminb06d69f2006-10-13 21:44:17 +0000[diff] [blame]116You might, for example, only want error messages to be logged, and not the other two types.
117If you set it to zero logging will be disabled.</p>
adminb0dd10f2006-08-25 17:25:49 +0000[diff] [blame]118
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Derek Allardc6441282007-07-04 23:54:32 +0000[diff] [blame]132</p>
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