Welcome to this Gallery2 Module Development tutorial.

The reason why i'll make this tutorial is because i personaly had trouble learning how to make custom modules.
I hope to make things more clear to you, so we'll find more tutorials online. :)

You will most likeley find some wrong phrases or grammer in this text, for english is not my native language.

Lets cut the talk, and i will explain some basics about modules, and how gallery2 works. (note that i will use G2 as a abbreviation for Gallery2)

How dous Gallery2 work?

- How the code lookes like
The thing what is very striking, is that G2 is Object Orientated. This basicly means you will be trown in quite some classes and methods.
You dont need to understand OOP (Object Orientated Programming) to make G2 Modules. It may be more easy to understand the code when you have some experience in OOP though.

- Storing data
Data can be stored in various ways.. Parameters, Maps and Entities. We'll start with parameters, for they are quite handy for storing a few values. With this, think about some text for a module, that you want to edit easily. Or maybe an email adress for a contact module?
But be carefull to not to store to much in your Parameter Map. When you'll build something like a guestbook, you dont want to use the Parameters. The parameter table is just one table, that contacts a few values of all modules. You dont want to fill the table with hundereds of entries of just one module.
When you will create something as big as a guestbook, you will choose for a map or entitie.

- How to controll the look of your module
G2 works with a Template Parser (Smarty). This means that you seperate your code from the layout. This is much cleaner, you will understand more about these templates when we'll start making a page.

- How your module is connected to G2
All of your actions are controlled via the API, this a sort of link between your module, and the core.


Make the base of the module!

Ok lets start with building our base. I will first show you the code, and after that we'll break the code, and handle each line.

CODE


- Eplained
First we need to define we're writing PHP code with
Followed by a block which contains Copyrights, license etc.

Now, you'll see a comment block with some info of your module. Just fill the lines with your own names, description etc.

After this is done, you will see the real deal. Starting some real code! "class JimsModule extends GalleryModule {" defines the name of the module. And also let G2 this is a module. You may only change the second word, and fill in your own. Dont change the GalleryModule name or something.

Ok, we have ourselves a start, now define the function of the class (OOP stuff, dont need to understand why..). WARNING: The function name, must be 100% the same as your class name! So when your classname is in this case JimsModule, your function also needs to be named JimsModule.

"global $gallery" grabs a variable from the system. We'll go further in this later.

Okay, now you'll see a few lines. These lines defines the name, description, version, etc etc.

Lets start with: $this->setId('jimsmodule');
Just fill in a clean name like above, no uppercase.

$this->setName($gallery->i18n('Jims Module'));
Defines a clean name, this is the name you will read in G2.

$this->setDescription($gallery->i18n('Description? Well, this shows you the base.'));
Description of your module.. No explenation needed right? :)

$this->setVersion('0.0.1');
The version of your script. Update this when you make a change on your module, this can be very handy, en ofcourse.. It is needed. :)

$this->setGroup('newgroup', $gallery->i18n('New Group'));
This defines the group. The group is where you will find your module listed in the admin panel. I used New Group to be more clear, but recommend to use an existing group. (just grab a group from the module page, which you think suits your module best.)

$this->setCallbacks('');
We'll come back to this line, it is not needed to fill in. But it comes with very nice feathures.

$this->setRequiredCoreApi(array(7, 10));
$this->setRequiredModuleApi(array(3, 2));
These are vesions of API's. This exists so you wont get problems when you import an old or new module, that dousn't work with your current G2 install. If you dont know what version you have, just grab a module from the galler2/modules/ directory. And open that module.inc file to check what the have.

And to end this, close your function and class with a }. And ofcourse we close the PHP script with ?>.

Save this file as module.inc

Now make a folder that contains the name of the module. ($this->setId('jimsmodule'); < this name)

Copy module.inc into the folder, and upload the folder to your gallery2/modules/ directory.

Now simply open your admin panel, go to the modules page. And you can activate your module. Next time we'll make a static page that uses a template.

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