July 15 2009
How To Create A Simple Display Module For PrestaShop
Tagged Under : ecommerce, modules, PHP, PrestaShop
Presumably many of you have wondered how to unleash the full power of PrestaShop, a bright light in the dark area of e-commerce platforms. Let’s have a look at the modules subject for PrestaShop and try to create one almost from scratch. This tutorial is of medium difficulty (OOP).
The advantage that PrestaShop has over its competition is definitely a modular structure that allows developers to create their own modules and themes that are scalable and portable. Using SMARTY template system makes it easier to get access to certain variables that certainly are likely to become a ground for our imagination.
The only problem with PrestaShop is its lack of solid documentation. Forum is bursting with questions to which developers are very unlikely to give answers because they simply don’t have time. Recently they have been upgrading the shop, fixing all the bugs that have been reported so it’s not their fault entirely. I hope that one day somebody will release a good info on PrestaShop, but until then I would like you to get cracking with creating your own modules after this tutorial.
Warning! This tutorial requires not only basic knowledge of PHP but also Object Oriented Programming skills (OOP)!
The back-end module file in PrestaShop
Modules in PrestaShop are like extenders to a basic (or should I say complex) shop’s functionality. Each module is stored within “modules” directory in its own folder. In general PrestaShop requires you to create only two files to make the module work:
- back-end processing script (PHP class-file);
- front-end display template file (for front-end modules only);
The back-end script is nothing more than a simple class file that is being recognized by the core as a backbone and all the instructions here are processed automatically to certain point. Basically when PS encounters a module file (has to have the same name as folder which the class-file is stored in) it searches for two main functions within it:
- __construct();
- install();
__construct() defines all the information about the module that will be displayed in the admin panel like version number, a name or description, etc. install() function aims to register the basic hook the one of the parts of the page. In the front-end of PS it is possible to use these hooks:
- hookHeader (hooks content of the template file to heading of the page between <head></head> tags;
- hookTop (hooks content of the template file to the top of the page, above the main content;
- hookLeftColumn or hookRightColumn (hooks content of the template file to one of the side panels);
- hookHome (displays the content on the homepage only);
- hookFooter (hooks content of the file to the footer);
The structure of the module is very simple, it looks like a simple class file:
Class functionName extends Module {
Function __construct()
{
$this->name = 'SampleModule';
$this->tab = 'Blocks';
$this->version = '1.0';
Parent::__construct();
$this->displayName = $this-> l(‘displayName’);
$this->description = $this->l(‘description’);
}
Function install()
{
//registers the basic hook
}
Function (hookName)($params)
{
//hooks the mod
}
}
Below this code you can add your own functions (well, you have to), so the module would come to life. A sample of the hook function is just here:
function hookHome($params)
{
global $smarty;
$category = new Category(1);
$nb = intval(Configuration::get('HOME_FEATURED_NBR'));
$products = $category->getProducts(intval($params['cookie']->id_lang), 1, ($nb ? $nb : 10), 'date_add', 'DESC');
$smarty->assign(array(
'allow_buy_when_out_of_stock' => Configuration::get('PS_ORDER_OUT_OF_STOCK', false),
'max_quantity_to_allow_display' => Configuration::get('PS_LAST_QTIES'),
'category' => $category,
'products' => $products,
'currency' => new Currency(intval($params['cart']->id_currency)),
'lang' => Language::getIsoById(intval($params['cookie']->id_lang)),
'productNumber' => sizeof($products)
));
return $this->display(__FILE__, 'ourcontent.tpl');
}
As you can see we can call PS configuration variables and use them within smarty to define variables for HTML template file so we won’t have needs for using PHP directly. If you’d like to hook the content to different areas but there would be no change in the content just create a second function with different hook that refers to our main hook, like:
function hookRightColumn($params)
{
return $this->hookHome($params);
}
To display a configuration page within admin panel we need to use a different pre-defined function called displayform(). This is a function that should render our desired content on the config page for our module. It might look like this one:
public function displayForm()
{
$output = '
';
return $output;
}
In order to process the content of the config form we need to use another pre-defined function, that is getcontent(). It will make sure that the form will be processed:
public function getContent()
{
$output = '
'.$this->displayName.'
';
if (Tools::isSubmit('submitHomeFeatured'))
{
$nbr = intval(Tools::getValue('nbr'));
if (!$nbr OR $nbr <= 0 OR !Validate::isInt($nbr)) $errors[] = $this->l('Invalid number of product');
else
Configuration::updateValue('HOME_FEATURED_NBR', $nbr);
if (isset($errors) AND sizeof($errors))
$output .= $this->displayError(implode('
', $errors));
else
$output .= $this->displayConfirmation($this->l('Settings updated'));
}
return $output.$this->displayForm();
}
TPL template module display file in PrestaShop
To conclude this tutorial it will be wise to display the content of our back-end script on the website. Since we hooked the content to the homepage the only thing we need to do is create a file with content called “ourcontent.tpl“:
Content:
{if isset($products) AND $products}{$product.name|escape:'htmlall':'UTF-8'}
{$product.description_short|strip_tags} {/if}
Now it’s just a matter of saving the files, uploading the whole module to the server and testing it until it works. Later on I will try to come up with the tutorial about using smarty variables in your modules and themes, as this is a very important issue that needs to have some light shed on it.
Until then good luck with your modules!
Thank you for the informative tutorial. I was looking to start writing a module for PS and this is a great start!
Thank you again for taking the time to post this!
Is there downloadable version of this sample?
I am currently working on downloadable PDF version but it might take a little bit, so please be patient ;). Also, are you interested in any more PrestaShop tutorials?
I’m working on a module http://bit.ly/IExjZ so a tutorial on hooking into PS functions would help
I followed your display tutorial and uploaded. Clicking modules now comes up blank under tabs. my php file http://bit.ly/Mt5UU
This was just an informative tutorial with few examples, it wasn’t meant to be working without some adjustments. And in your code you forgot about preparing the install() function which determines whether the mod will be seen in the back-end (if there is no install function PS will can’t display the install button, etc.).
Very great, thank you for taking time to write it its very useful. I am interested to read a tutorial how to create an completely new table in database and retrieve the data.
Thank you again.
Thanks for your comments, of course I will be posting more and more articles about PrestaShop as there are still people struggling to get it to work as they want it to, so stay tuned. If it comes to the database table creation will you need it for storing some custom settings?
Hey that was a great tut ….. Really ps lacks docs… and this tut made it up for a start… Now atleast i can start cracking the code and learn it… thanks man..i am loking forward to see more from you… mail me if i can be of any help..im new in ps but im working in php smarty mysql for 1yr… hope i will be able to get into the core of this one….
Thanks for the tutorial. Would you mind sharing how to create Prestashop theme? I can only find tutorial which teach how to change color with css on internet :(
I will soon try to post a tutorial on full aspects of creating the PrestaShop theme and styling it up. Thanks for your comments :)
Thanks for the tutorial. I would like to know how to make a survey form in a module. Do you think if you can show us how?