View source for Geeklog's way of doing things

All of Geeklog's php files are pure php. PHP allows you to use php as a scripting language imbedded in html files but this is not how Geeklog does it. All of Geeklog's php files must have <?php as the first five characters and end with ?>. Failure to structure your Geeklog files this way will cause session and header errors. Geeklog attempts as much as possible to have only PHP code in the .php files. Two of the conventions used in Geeklog to accomplish this are the use of templates and language files.

Time will be well spent by the Geeklog plugin or block developer to become familiar with several Geeklog libraries. The following section outlines the more important or frequently used libraries, functions and standards. 


== lib-common.php ==

The Geeklog plugin or block developer should have a good understanding of <tt>lib-common.php</tt> which contains most of the display routines as well as some other general purpose routines. All of the Geeklog display routines return HTML. They do not contain echos or prints themselves. The way the Geeklog system is designed; you usually put your code between Geeklog display routines. For example: code to display a page would look like this: 

<pre>
$display  = COM_siteHeader();
$display .= COM_startBlock("Title of Your Block");
$display .= "Some words";
$display .= somefunction();
$display .= COM_endBlock;
$display .= COM_siteFooter(true);
echo $display;
</pre>

A summary of commonly used Geeklog functions are described below but reference [http://project.geeklog.net/src/Geeklog/_public_html---lib-common.php.html <tt>lib-common.php</tt> documentation] for further examples. 


== lib-security.php ==

The <tt>lib-security.php</tt> file contains the interface routines to the security system used in Geeklog. See the [http://project.geeklog.net/src/Geeklog/_system---lib-security.php.html <tt>lib-security.php</tt> documentation]. There are several SEC type functions that you may want to use in your projects. The table Commonly Used Geeklog Functions at the end of this section defines a couple of the more commonly used functions.


== lib-database.php ==

All database access should take place through the database abstraction in <tt>lib-database.php</tt> and table names should be accessed through the <code>$_TABLES</code> array. The table definitions in this array will then include whatever table prefix this site is using.  You should ensure that your plugin or block uses the <code>$_TABLES['mytable']</code> for all database access related functions.

* Block developers and site admins installing the block need to make sure that any tables needed by a block are added to the <code>$_TABLES</code> array. Ensure you follow the same standard by using the $_DB_table_prefix. However, you should '''not''' edit <tt>lib-database.php</tt>. If no suitable place can be found in the block's code, the addition should be done in <tt>lib-custom.php</tt> instead.
* Plugin developers need to define their tables in the plugin <tt>config.php</tt> file (or some other suitable file belonging to the plugin, e.g. <tt>functions.inc</tt>). You have the ability to use the <code>$_TABLES</code> array or use your own plugin specific array to maintain the table definitions. It's recommend that your arrays use a name such as <code>_XX_TABLES</code>, where XX are two letters to describe your plugin. Once the plugin is installed and enabled, the tables defined for the plugin are automatically known as globals.


== lib-plugins.php ==

This library contains all the code used to interface your plugin or block to Geeklog. You will not call any code from here directly. The functions in this file are called by the Geeklog main programs as they are used to call all plugins and are used to resolve the plugin name and check if your plugin has a particular function. You will usually only have to look at this file to understand some nuance of the implementation. See the documentation for <tt>functions.inc</tt> and the original plugin documentation for further help. 


== How your Plug-in or Block Interacts with Geeklog ==

The program <tt>lib-common.php</tt> is the key to all interaction with Geeklog. It includes all of the Geeklog code libraries.

* At the top of <tt>lib-common.php</tt> is an include of <tt>lib-custom.php</tt>. This is where you place all your block functions. They are then included when the site <tt>index.php</tt>2 is called. 
* At the very end of <tt>lib-common.php</tt> is a check for all enabled plugins. A plugin is registered with Geeklog when it has a record in the plugins table and the field <tt>pi_enabled</tt> is <tt>1</tt>. For all registered and enabled plugins, the code in <tt>lib-common.php</tt> will include the <tt>functions.inc</tt> file for each plugin. This is why the naming convention and location for each plugin file is strictly defined. All code libraries or configuration files your plugin needs should be included in your <tt>functions.inc</tt>. Since the plugin's <tt>config.php</tt> (if it exists) is now also included this way - via the include in <tt>functions.inc</tt> - the variables in your plugin <tt>config.php</tt> become global and can be referenced in your plugin functions.


== Common Global Variables ==

There are a few commonly used globals within Geeklog that you will want to use and reference. The following table outlines the more frequently used ones and its recommended that these be used instead of hard coding paths and table names in your links or project code.

<table border="1" cellpadding="3" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="75%" id="AutoNumber2" height="72">
  <tr>
    <td width="27%" bgcolor="#000000" height="16">
    <font color="#FFFFFF" size="2">&nbsp;Variable</font></td>
    <td width="73%" bgcolor="#000000" height="16">
    <font color="#FFFFFF" size="2">&nbsp; Description</font></td>
  </tr>
  <tr>
    <td width="27%" height="17"><font size="2">$_CONF['path_html']</font></td>
    <td width="73%" height="17"><font size="2">Fully qualified path to your 
    sites public_htmk path</font></td>
  </tr>
  <tr>
    <td width="27%" height="18"><font size="2">$_CONF['site_url']</font></td>
    <td width="73%" height="18"><font size="2">Full URL to your sites 
    public_html directory</font></td>
  </tr>
  <tr>
    <td width="27%" height="18"><font size="2">$_CONF['site_admin_url']</font></td>
    <td width="73%" height="18"><font size="2">Full URL to your sites admin 
    directory</font></td>
  </tr>
  <tr>
    <td width="27%" height="18"><font size="2">$_USER['uid']</font></td>
    <td width="73%" height="18"><font size="2">Current user ID. A uid of 1 is an 
    anonymous user</font></td>
  </tr>
  <tr>
    <td width="27%" height="18"><font size="2">$_TABLES['tablename']</font></td>
    <td width="73%" height="18"><font size="2">A array of geeklog tables with 
    the site prefix defined.</font></td>
  </tr>
</table>


== Commonly used Geeklog functions ==

The following is a list of commonly used Geeklog functions that as developers we use and recommend you become more familiar with and use in your development projects. You will find example usage of these functions throughout the Geeklog code. 

<table border="1" style="border-collapse: collapse" bordercolor="#111111" width="100%" id="AutoNumber1" height="197" cellpadding="3" cellspacing="0">
  <tr>
    <td width="13%" bgcolor="#000000" height="18">
    <font color="#FFFFFF" size="2">&nbsp;Function Name</font></td>
    <td width="73%" bgcolor="#000000" height="18">
    <font color="#FFFFFF" size="2">&nbsp;&nbsp; Description</font></td>
  </tr>
  <tr>
    <td width="13%" height="16">
    <font size="2">&nbsp;COM_siteHeader</font></td>
    <td width="73%" height="16"><font size="2">Display the main site header and optionally if 'none' is passed <b>do not </b>display the left blocks</font></td>
  </tr>
  <tr>
    <td width="13%" height="16">
    <font size="2">&nbsp;COM_siteFooter</font></td>
    <td width="73%" height="16"><font size="2">Display the main site footer and optionally if 'true' is passed display the right blocks</font></td>
  </tr>
  <tr>
    <td width="13%" height="32">
    <font size="2">&nbsp;COM_startBlock</font></td>
    <td width="73%" height="32"><font size="2">Formats the block title using the selected theme - pass the title, helpfile if any and optional block theme to apply if you do not want to use default</font></td>
  </tr>
  <tr>
    <td width="13%" height="16">
    <font size="2">&nbsp;COM_endBlock</font></td>
    <td width="73%" height="16"><font size="2">Formats the block footer using the selected theme or the optional block theme if you do not want to use default</font></td>
  </tr>
  <tr>
    <td width="13%" height="12"><font size="2">&nbsp;COM_errorLOG</font></td>
    <td width="73%" height="12"><font size="2">Use to format an error message or 
    use for debugging - view output in &lt;geeklog_dir&gt;/logs/error.log</font></td>
  </tr>
  <tr>
    <td width="13%" height="14">
    <font size="2">&nbsp;DB_query</font></td>
    <td width="73%" height="14"><font size="2">Execute a formatted SQL query and 
    return the record set to an array of records (which is also an array)</font></td>
  </tr>
  <tr>
    <td width="13%" height="16">
    <font size="2">&nbsp;DB_fetchArray</font></td>
    <td width="73%" height="16"><font size="2">Retrieve a record as an array 
    from the returned record set - which DB_query returned.</font></td>
  </tr>
  <tr>
    <td width="13%" height="16">
    <font size="2">&nbsp;DB_numROWS</font></td>
    <td width="73%" height="16"><font size="2">Returns the number of records 
    retrieved by the DB_query result</font></td>
  </tr>
  <tr>
    <td width="13%" height="16"><font size="2">&nbsp;DB_getItem</font></td>
    <td width="73%" height="16"><font size="2">Retrieve one record as an array. 
    Pass a formatted SQL stmt with WHERE clause to retrieve one record</font></td>
  </tr>
  <tr>
    <td width="13%" height="15"><font size="2">&nbsp;COM_checkHTML</font></td>
    <td width="73%" height="15"><font size="2">Use to strip out $, &lt;, &gt; , [code] 
    and replace with the HTML codes</font></td>
  </tr>
  <tr>
    <td width="13%" height="15"><font size="2">&nbsp;COM_checkWords</font></td>
    <td width="73%" height="15"><font size="2">Use to check passed text for any 
    HTML tags that are not allowed as per the site config.php setting</font></td>
  </tr>
  <tr>
    <td width="13%" height="15"><font size="2">&nbsp;SEC_inGroup</font></td>
    <td width="73%" height="15"><font size="2">Used to check if user has passed 
    group rights. Example: SEC_inGroup('Root') - returns true if user is</font></td>
  </tr>
  <tr>
    <td width="13%" height="15"><font size="2">&nbsp;SEC_hasRights</font></td>
    <td width="73%" height="15"><font size="2">Used to check if user has access 
    right (feature). Example: SEC_hasRights('myplugin.edit')</font></td>
  </tr>
</table>


[[Category:Plugin Developers Handbook]] [[Category:Plugin Development]]