Jan Štětina

This plugin provides a simple API for storing miscellaneous log entries and their overview in admin area (or network 
admin area, if activated on a multisite).
Developed for private use (heavily used by my other plugins), but has perspective for more extensive usage. I can’t guarantee any support in the future nor further development, but it is to be expected. Kindly inform me about bugs, if you find any, or propose new features: <a href="mailto:zaantar@zaantar.eu?subject=[wordpress-logging-service]" rel="nofollow ugc">zaantar@zaantar.eu</a>.
See Usage and FAQ for more information.
<h3>API</h3>
Definitions:
<pre><code>WLS
</code></pre>
<ul>
<li>
should be checked before using any wls function
WLS_VERSION
</li>
<li>
should(!) contain current WLS version string
</li>
<li>
severity levels:
<pre><code>WLS_NOCATEGORY = 0

WLS_INFO = 1

WLS_NOTICE = 2

WLS_WARNING = 3

WLS_ERROR = 4

WLS_FATALERROR = 5
</code></pre>
</li>
</ul>
Functions:
<pre><code>wls_is_registered( $category_name );
</code></pre>
<ul>
<li>
returns <code>true</code>, if <code>$category_name</code> is registered
wls_register( $category_name, $description );
</li>
<li>
registers <code>$category_name</code> as a log category.
</li>
<li>
<code>$description</code> will be shown in admin area
wls_clear( $category_name );
</li>
<li>
deletes all log entries of category $category_name
wls_unregister( $category_name );
</li>
<li>
same as wls_clear & removes category $category_name from the list
wls_log( $category_name, $text, $user_id, $date, $blog_id, $severity = 0 );
</li>
<li>
inserts a new log entry into specified category
</li>
<li><code>$date</code> must be formated according to ISO 8601</li>
<li>
<code>$severity</code> should be one of defined severity levels (see above)
wls_simple_log( $log_name, $text, $severity = 0 );
</li>
<li>
equivalent to <code>wls_log( $category_name, $text, get_current_user_id(), date( 'c' ), get_current_blog_id(), $severity);</code>
</li>
</ul>

WordPress Logging Service

Provides a simple API for storing miscellaneous log entries and their overview in admin area.

Stefan Boonstra

Developer Tools currently only supports logging of variables, errors and exceptions. Features such as profiling a 
website’s database queries and server memory usage are not yet supported.
<h4>Features</h4>
<ul>
<li>Log any type of variable</li>
<li>Log any catchable error or exception</li>
<li>Watch for new log entries through the backend interface</li>
<li>No bloating the live environment with developer dumps</li>
<li>That’s it for now 🙂</li>
</ul>
<h4>Need the (uncompressed) source code?</h4>
Find the Slideshow project’s source code in my <a href="https://github.com/Boonstra/WordPress-Developer-Tools" rel="nofollow ugc">GitHub</a> repository. The 
uncompressed files can be compiled using <a href="http://alphapixels.com/prepros/" rel="nofollow ugc">Prepros</a>, or <a href="http://incident57.com/codekit/" rel="nofollow ugc">CodeKit</a>.
<h3>Links</h3>
<ul>
<li><a href="http://stefanboonstra.com/" rel="nofollow ugc">Stefan Boonstra</a></li>
<li><a href="https://github.com/Boonstra/WordPress-Developer-Tools" rel="nofollow ugc">GitHub</a></li>
</ul>

Basic Developer Tools

Basic Developer Tools helps developers to log any variable, error or exception of which they need the value, without bloating their live environment.

WordPress Logging Service vs Basic Developer Tools