wyrfel

LogStore can be used to log (important) data from within your plugin. 
It provides a simple interface to log entries and a friendly administration interface for viewing and managing the log entries.
While LogStore can be used to log debug output or system events, it’s main intention is to log more extensive data, such as:
<ul>
<li>system emails sent your users</li>
<li>data received from remote API calls</li>
</ul>
<h3>Usage</h3>
To use LogStore in your plugin, add the following line to your plugin’s ‘plugins_loaded’ callback function:
<pre><code>if (class_exists('LogStore')) $this->log = new LogStore('slug', __('Title'));
</code></pre>
<ul>
<li>The ‘slug’ should be a unique identifier for your logger.</li>
<li>The ‘Title’ will be the title used in menu entries, options and page titles.</li>
</ul>
Once that’s done you can then start logging your data from anywhere within your plugin by using the following:
<pre><code>if (!empty($this->log)) $this->log->log(__('My log message'), $my_log_data, 'status', 'tag');
</code></pre>
<ul>
<li>‘My log message.’ is any arbitrary message to describe your log entry.</li>
<li>$my_log_data is the extended data you want to log. This can be either an array or string.</li>
<li>‘status’ is one of ‘none’, ‘ok’, ‘warn’, ‘critical’ or ‘fatal’.</li>
<li>‘tag’ can be any kind of singular tag to further classification to your log entries.add</li>
</ul>
If you use LogStore in your plugin, you should check for it’s presence in
<ul>
<li>your ‘plugins_loaded’ callback</li>
<li>your plugin activation callback</li>
</ul>
You should either make LogStore use optional or notify the user that they need to install LogStore for your plugin to work properly.
<h3>Plugin Hooks</h3>
In the following hooks, <code>*myname*</code> stands for the name with which you instanciated the LogStore class.
<h4>Action Hooks</h4>
<ul>
<li><code>logstore_init-*myname*</code> – runs during the execution of WP’s <code>init</code> action hook, passes a single boolean parameter indicating if logging is active or inactive for this logger</li>
</ul>
<h4>Filter Hooks</h4>
<ul>
<li><code>logstore_new_entry-*myname*</code> – runs during the creation of a new entry, passes a single array containing all values for that entry (‘time’, ‘message’, ‘data’, ‘status’ and ‘tag’)</li>
<li><code>logstore_entry-*myname*</code> – runs before displaying an entry on screen, passes a single array containting all values for the entry (‘time’, ‘message’, ‘data’, ‘status’ and ‘tag’)</li>
<li><code>logstore_format_entry_data-*myname*</code> – runs before displaying the formatted data on screen, passes the formatted data as string</li>
</ul>
<h3>Further Notes</h3>
Please note that the ‘bulk actions’ in the log viewer are currently not 
working.

LogStore

LogStore is a 'meta' plugin that allows other plugins to log data easily.

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.

LogStore vs WordPress Logging Service