Difference between revisions of "Geeklog's way of doing things"

Revision as of 21:05, 28 June 2004

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 lib-common.php 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:

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

A summary of commonly used Geeklog functions are described below but reference the attached lib-common.php documentation for further examples.

lib-security.php:

The lib-security.php file contains the interface routines to the security system used in Geeklog. See the attached lib-security.php 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 lib-database.php and table names should be accessed through the $_TABLES 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 $_TABLES['mytable'] for all Database access related functions.

• Block developers and site admins installing the block need to edit the lib-database.php program and add the new $_TABLES entries for your block tables. Ensure you follow the same standard by using the $_DB_table_prefix.
• Plugin developers need to define their tables in the plugin config.php file. You have the ability to use the $_TABLES array or use your own plugin specific array to maintain the table definitions. It's recommend that your arrays use a name such as _XX_TABLES, where XX are two letters to describe your plugin. Once the plugin is installed and enabled, the tables defined in the config.php 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 functions.inc and the original plugin documentation for further help.

How your Plug-in or Block Interacts with Geeklog:

The program lib-common.php is the key to all interaction with Geeklog. It includes Geeklog's config.php and the rest of the Geeklog code libraries.

• At the top of lib-common.php is an include of lib-custom.php. This is where you place all your block functions. They are then included when the site index.php is called.
• At the very end of lib-common.php 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 pi_enabled is true. For all registered and enabled plugins, the code in lib-common.php will include the functions.inc 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 functions.inc. Since the plugins config.php is now also included this way - via the include in functions.inc - the variables in your plugin config.php 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.

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.

Function Name
   Description 
COM_siteHeader
Display the main site header and optionally if 'none' is passed do not display the left blocks 
COM_siteFooter
Display the main site footer and optionally if 'true' is passed display the right blocks 
COM_startBlock
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 
COM_endBlock
Formats the block footer using the selected theme or the optional block theme if you do not want to use default 
COM_errorLOG Use to format an error message or use for debugging - view output in <geeklog_dir>/logs/error.log 
DB_query
Execute a formatted SQL query and return the record set to an array of records (which is also an array) 
DB_fetchArray
Retrieve a record as an array from the returned record set - which DB_query returned. 
DB_numROWS
Returns the number of records retrieved by the DB_query result 
DB_getItem Retrieve one record as an array. Pass a formatted SQL stmt with WHERE clause to retrieve one record 
COM_checkHTML Use to strip out $, <, > , [code] and replace with the HTML codes 
COM_checkWords Use to check passed text for any HTML tags that are not allowed as per the site config.php setting 
SEC_inGroup Used to check if user has passed group rights. Example: SEC_inGroup('Root') - returns true if user is 
SEC_hasRights Used to check if user has access right (feature). Example: SEC_hasRights('myplugin.edit')