When you build an expansion you can create some different parts:

- The expansion part relative to the panels;
- The expansion part relative to the pages;
- The expansion part relative to the administrators area;
- The expansion part relative to the users area;
- The expansion part relative to the kernel stage.

Each part have the rules to execute the expansion in the different area of your website. You can also create a multilanguages expansion.

To create an expansion you must create a new folder in "core/expansion", in this new folder you must create:

- A "config.php" file;
- An executable (.php) file for administrator stage;
- An executable (.php) file for user stage;
- An executable (.php) file for kernel stage;
- An executable (.php) file used in expansion pages;
- An executable (.php) file used in expansion panels;
- An "icon.png" file (a 48x48 png icon file for administrator/user menu);
- A folder with languages files.

1) Expansion config file:
The "config.php" file contains all the expansion configuration parameters and have the following structure:

All parameters are within the array $_EXPANSION[]. The parameters that can be used are as follows:

2) Expansion executable files:
An executable file its a php file that will contain the expansion code, you can create a different executable file for each expansion part.
Executable file must have the following structure:

In the executable file you can use all the api of Webmatic (see APIs references).
In an executable file you can use also a global variable called "$w3", this variable is a global instance of "webmatic3" class. You can use the $w3 global variable to call all the public and non static methods of webmatic3 class, for example you can write:

to retrive the current home page language ID.

3) Expansion languages files:
To create a multilanguage expansion you need to create a language file for each language you want to support in the expansion.
According with $_EXPANSION['language_path'] parameter, you must create in the folder specified in $_EXPANSION['language_path'] parameter all the language files you need (in this folder you must create at least the "language_en.php" file because english is the default expansions language).
All the language file you need to create must have this name "language_xx.php" where "xx" is the standard language code (for example "language_it.php", "language_de.php", ...).
A language file must have the following structure:

When you build an expansion you may need to pass it some custom parameters.
To give the parameters and the respective values to an expansion page or panel, you must insert them in the "Expansion parameters" field when you create an expansion panel or an expansion page (see user manual and picture 1).
You must insert in a first line the parameter names in brackets and the values must follow the parameter names in a second line (you can use only a single line for the value). As shown in picture 1 there are 2 parameters (name and age) with 2 values ("Peter" for the "name" parameter and "32" for the "age" parameter).

(1)

You can use the expansion parameters with some simple functions, you can use those functions in an executable (.php) file.