Starting with a simple module

First, download the project file, and place the module you will find inside the “start” folder in the modules/ folder of your prestashop installation.

Open up displaybocategorytut.php, it’s just a very basic module structure.

if (!defined('_PS_VERSION_'))
	exit;

class displayBoCategoryTut extends Module
{

	protected $_errors = array();
	protected $_html = '';


	public function __construct()
	{
		$this->name = 'displaybocategorytut';
		$this->tab = 'front_office_features';
		$this->version = '1.0';
		$this->author = 'Nemo';
		$this->need_instance = 0;
		
		$this->bootstrap = true;

	 	parent::__construct();

		$this->displayName = $this->l('Display BO Category Tutorial');
		$this->description = $this->l('Displays an additional field in the category back office');
	}
	
	public function install()
	{
		if (!parent::install())
			return false;
		return true;
	}

	public function uninstall()
	{
		if (!parent::uninstall())
			return false;
		return true;
	}

}

The first thing we need is of course some additional data we want to save and retrieve. For this reason, we need an extra method to modify the database, and add a further column to the category table:

	public function alterTable($method = 'add')
	{
		if($method == 'add')
			$sql = 'ALTER TABLE ' . _DB_PREFIX_ . 'category ADD `myowninput` VARCHAR (255) NOT NULL';
		else 
			$sql = 'ALTER TABLE ' . _DB_PREFIX_ . 'category DROP COLUMN `myowninput`';

		if(!Db::getInstance()->Execute($sql))
			return false;
		return true;
	}

Explanation: since we need the extra column, we are using a single method to add and remove it. We are passing in a “method” parameter, so that we can switch between actions depending on our needs.

As mentioned, we need this column to be added when installing, and removed when uninstalling, so let’s amend the install and uninstall methods as well:

	public function install()
	{
		if (!parent::install() OR
			!$this->alterTable() OR
			!$this->registerHook('displayBackOfficeCategory') OR
			!$this->registerHook('categoryAddition') OR
			!$this->registerHook('categoryUpdate')
			)
			return false;
		return true;
	}

	public function uninstall()
	{
		if (!parent::uninstall() OR
			!$this->alterTable('remove'))
			return false;
		return true;
	}

Additionally, I am registering two hooks to update the field’s value. This would not be necessary if we had a Category class override to take care of the extra field (see more on Extending PrestaShop Objects).

Next, we will need some way to retrieve our custom field from the database

	public function getMyOwnInput($id_category)
	{
		return Db::getInstance()->getValue('SELECT myowninput FROM '._DB_PREFIX_.'category WHERE id_category = '. (int)$id_category);
	}

Then, it’s time to display something in the category back office. Let’s create the hooking method:

	public function hookDisplayBackOfficeCategory($params)
	{

		// we need an actual id, otherwise if we are just adding the category this field can be left empty
		if(Tools::getValue('id_category'))
			$myowninput = $this->getMyOwnInput(Tools::getValue('id_category'));
		else $myowninput = '';

		$this->context->smarty->assign(array(
			'myowninput'=> $myowninput
		));


		return $this->display(__FILE__, 'backoffice.tpl');
	}

Explanation: First off, we make sure we have a category ID that we can use to retrieve the value from the database. We use a switch to prevent the script from causing trouble in case there is none (that is, we are just creating a new category). Then, we assign the input value to the template, and return it. We don’t have it yet, so let’s create a new file inside views\templates\hook, naming it backoffice.tpl

Let’s add some simple markup:

<div class="form-group">
	<label class="control-label col-lg-3">
		<span class="label-tooltip">
			{l s='Custom Input' mod='displaybocategorytut'}
		</span>
	</label>
	<div class="col-lg-4">
		<input type="text" name="myowninput" value="{$myowninput}">
	</div>
	<div class="col-lg-6 col-lg-offset-3">
	</div>
</div>

We are ready to install the module! Go ahead and do it from the modules page. If everything goes smoothly as it should, reach a category and click edit (or add one). It should display our new field:

It won’t do much at the time being, since we are not saving the value on submit. For this, we need another couple of methods that will take advantage of the hooks we registered upon install:

	public function hookCategoryAddition($params)
	{
		Db::getInstance()->update('category', array('myowninput' => pSQL(Tools::getValue('myowninput'))), 'id_category = ' . $params['category']->id);
	}

	public function hookCategoryUpdate($params)
	{
		$this->hookCategoryAddition($params);
	}

Explanation: here we are using some standard code to update the database: the myowninput value is sent over via POST when submitting the page, and the $params variable passed to the method contains a useful Category object, from which we are taking the ID.

Now write something in the field and save, it should be stored in the database! To make sure everything runs smoothly, create a new category as well, adding content to our field before submitting the page.

Once everything works, you can try to expand the module with hooks, in the front office as well, and take full advantage of the new value.

Additional Resources

• Learn how to develop PrestaShop Modules with my PrestaShop Modules Course

The post Hooking modules to the Category Back Office in Prestashop appeared first on NemoPS.

Creating a custom hook for CMS pages

The first step is to create a new, custom hook and add it to the cms.tpl file. We will be using the new way to add hooks introduced in Prestashop 1.5.

Locate your cms.tpl inside the theme’s folder, and open it up in any code editor. Please notice yours might look different from mine, as I am using Prestashop 1.6.0.8

{if isset($cms) && !isset($cms_category)}
	{if !$cms->active}
		<br />
		<div id="admin-action-cms">
			<p>
				<span>{l s='This CMS page is not visible to your customers.'}</span>
				<input type="hidden" id="admin-action-cms-id" value="{$cms->id}" />
				<input type="submit" value="{l s='Publish'}" name="publish_button" class="button btn btn-default"/>
				<input type="submit" value="{l s='Back'}" name="lnk_view" class="button btn btn-default"/>
			</p>
			<div class="clear" ></div>
			<p id="admin-action-result"></p>
			</p>
		</div>
	{/if}
	<div class="rte{if $content_only} content_only{/if}">
		{$cms->content}
	</div>
{elseif isset($cms_category)}
	<div class="block-cms">
		<h1><a href="{if $cms_category->id eq 1}{$base_dir}{else}{$link->getCMSCategoryLink($cms_category->id, $cms_category->link_rewrite)}{/if}">{$cms_category->name|escape:'html':'UTF-8'}</a></h1>
		{if $cms_category->description}
			<p>{$cms_category->description|escape:'html':'UTF-8'}</p>
		{/if}
		{if isset($sub_category) && !empty($sub_category)}	
			<p class="title_block">{l s='List of sub categories in %s:' sprintf=$cms_category->name}</p>
			<ul class="bullet list-group">
				{foreach from=$sub_category item=subcategory}
					<li>
						<a class="list-group-item" href="{$link->getCMSCategoryLink($subcategory.id_cms_category, $subcategory.link_rewrite)|escape:'html':'UTF-8'}">{$subcategory.name|escape:'html':'UTF-8'}</a>
					</li>
				{/foreach}
			</ul>
		{/if}
		{if isset($cms_pages) && !empty($cms_pages)}
		<p class="title_block">{l s='List of pages in %s:' sprintf=$cms_category->name}</p>
			<ul class="bullet list-group">
				{foreach from=$cms_pages item=cmspages}
					<li>
						<a class="list-group-item" href="{$link->getCMSLink($cmspages.id_cms, $cmspages.link_rewrite)|escape:'html':'UTF-8'}">{$cmspages.meta_title|escape:'html':'UTF-8'}</a>
					</li>
				{/foreach}
			</ul>
		{/if}
	</div>
{else}
	<div class="alert alert-danger">
		{l s='This page does not exist.'}
	</div>
{/if}
<br />
{strip}
{if isset($smarty.get.ad) && $smarty.get.ad}
{addJsDefL name=ad}{$base_dir|cat:$smarty.get.ad|escape:'html':'UTF-8'}{/addJsDefL}
{/if}
{if isset($smarty.get.adtoken) && $smarty.get.adtoken}
{addJsDefL name=adtoken}{$smarty.get.adtoken|escape:'html':'UTF-8'}{/addJsDefL}
{/if}
{/strip}

We first need to decide where to put our module, if before the cms content, or after it. Whichever position you choose (you might also add two hooks, one before, one after), the important section of the page is the following:

<div class="rte{if $content_only} content_only{/if}">
	{$cms->content}
</div>

I strongly advice to insert new hooks right outside the rte container block, to avoid cms styles to override the ones of any eventual module. At this point, let’s add the hook.

{hook h='customCMS'}

<div class="rte{if $content_only} content_only{/if}">
	{$cms->content}
</div>

As you can see, I decided to add mine right before the cms content block. It is important to notice the $content_only variable. If you prefer the hook not to be executed when viewing the cms page in a lighbox, you need to wrap it inside an if statement:

{if !$content_only} 
{hook h='customCMS'}
{/if}

<div class="rte{if $content_only} content_only{/if}">
	{$cms->content}
</div>

This way, if you hooked something to your terms and conditions, this hook will not be executed when displaying the specific cms page in the checkout popup.

How to hook Modules to CMS pages

We have our custom hook. It’s time to decide which module we want to plug to a cms page.

Given that it cannot be done without modifying core module files (and by editing a native module we are not given the chance to upgrade it without losing modifications), to make our lives easier it’s generally a good idea to simply clone/call an existing hooking method.

In the example, I will use the Featured Products block module, to display the featured products list in a cms page (for no reason!). Therefore, open up homefeatured.php, located at modules/homefeatured, and then locate the install method:

	public function install()
	{
		$this->_clearCache('*');
		Configuration::updateValue('HOME_FEATURED_NBR', 8);

		if (!parent::install()
			|| !$this->registerHook('header')
			|| !$this->registerHook('addproduct')
			|| !$this->registerHook('updateproduct')
			|| !$this->registerHook('deleteproduct')
			|| !$this->registerHook('categoryUpdate')
			|| !$this->registerHook('displayHomeTab')
			|| !$this->registerHook('displayHomeTabContent')
		)
			return false;

		return true;
	}

We called our hook customCMS, so we need to register this during the module’s install:

	public function install()
	{
		$this->_clearCache('*');
		Configuration::updateValue('HOME_FEATURED_NBR', 8);

		if (!parent::install()
			|| !$this->registerHook('header')
			|| !$this->registerHook('addproduct')
			|| !$this->registerHook('updateproduct')
			|| !$this->registerHook('deleteproduct')
			|| !$this->registerHook('categoryUpdate')
			|| !$this->registerHook('displayHomeTab')
			|| !$this->registerHook('displayHomeTabContent')
			|| !$this->registerHook('customCMS')
		)
			return false;

		return true;
	}

Then, we need to add the hooking method at the end of the file, before the closing bracket

	public function hookcustomCMS($params)
	{
		return $this->hookDisplayHome($params);
	}

This way, we are simply calling the default method used (not in 1.6, as that’s the tab one) to show the block in the homepage. We could as well clone the same method and change it as we prefer, of course (for example if we need to use another template), but this is the quickest way.

Save and reset the module, then navigate to any cms page:

It’s displaying, and that’s fine. However, it’s being shown in every CMS page! How to deal with it?

Target specific cms page in the hooking method

We obviously don’t want to display a module in every cms page, so we have to find a way to target each specific one. How? The quickest way is to use the CMS page ID, which is the number highlighted in the following screen.

If you use friendly urls, the ID will precede the page’s slug, like 1-delivery, where 1 is the ID. If not, the id is the number following id_cms= in the url.

Alternatively, it’s also displayed at the far left or the table listing all available cms pages, in the back office:

Once we have this information, let’s use it in our new, custom hooking method:

	public function hookcustomCMS($params)
	{

		if (Tools::getValue('id_cms') != 1)
			return;
		return $this->hookDisplayHome($params);
	}

And we are done! Try to navigate to other pages. In my case, I will only see the block if I view the Delivery Information CMS.

The post How to add hooks to Prestashop CMS pages appeared first on NemoPS.

Watch the screencast

Text version

The old VS the new hooks syntax

If you were used to adding hooks to Prestashop 1.4, you might remember having to write something like this

INSERT INTO `ps_hook` (`name`, `title`, `description`) 
VALUES ('category', 'Category', 'Hooks before the product list in a category');	

Into your database to add the hook, and then override one of the controllers to register its execution, like this:

Class FrontController extends FrontControllerCore
{
 
    public function displayHeader()
    {
        if (!self::$initialized)
             $this->init();
 
            self::$smarty->assign('HOOK_CATEGORY', Module::hookExec('category'));
 
        parent::displayHeader();        
    }
 
}

And this was SO bad, forcing us to use overrides for almost every place which didn’t have its own hook already.

Luckily, but “secretly” for some reason, a new and simpler way has been introduced, and that is, substantially, adding this to a template file:

	{hook h='nameOfTheHook'}

I discovered it by chance actually, scrabbing throughout the forums, from a post of one the Prestashop Core’s developers: Fabien Serny (reference)

Example: adding a new hook for the first time

For the sake of this example, we’ll just be writing some piece of text above the footer. Therefore, open up themes/default/footer.tpl, and right before {$HOOK_FOOTER}, add the following

	{hook h='beforeFooter'}	

The name is, of course, discretional. Nothing else has to be done actually, but registering the hook as any other existent hook. Open up any module you have installed, for example blocknewsletter.php. I’ll be using this for demonstrational purposes only, you can use any. At the end of the file, add a simple hooking function:

	
public function hookBeforeFooter($params)
{
	return 'hi there!';
}

The function is now there, but this module is not registered as being part of this hook. We won’t be able to position it to the new hook from the back office yet. The first time you create the hook, it has to be registered at least once, from a module. We can use a regular registerHook for this, as any other hook. In the install() function of the module, add the registration, so it looks like this:

	if (parent::install() == false || $this->registerHook('leftColumn') == false ||  $this->registerHook('beforeFooter') == false || $this->registerHook('header') == false)
		return false;	

Again, this is just an example, the important part is the following one (it will look familiar if you know how to create modules and register hooks; if it doesn’t, have a look at my previous tutorial about Prestashop Hooks, as the basic ideas are still valid):

	$this->registerHook('beforeFooter')

Go back to the modules panel and reset the module (or install it, if it wasn’t). Refresh the front office, and you’ll see the “Hi there!” text appear where it’s supposed to be.

Isn’t this a HUGE improvement? Yay, it is. But if you still use Prestashop 1.4, you can go the old way with my module EZ Hooks, and create new hooks in 1 click.

The post Quick Tip: Adding hooks to Prestashop 1.5 (the new way) appeared first on NemoPS.