Table of contents
Table of Contents |
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Using the Context Object
What is the Context object?
The Context is a technical feature introduced with version 1.5 of PrestaShop. Its two goals are:
- preventing developers from using global variables.
- enabling them to change the context of some methods.
The Context is a registry for PHP variables that were previously accessed as globals. It aims to standardize the way these variables are accessed, and to make the code more robust by getting rid of global vars.
It is a light implementation of the Registry design pattern: it is a class that stores the main PrestaShop information, such as the current cookie, the customer, the employee, the cart, Smarty, etc.
Before version 1.5, you had to rely on the cookie in order to access this data:
Code Block | ||||
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$cookie->id_lang; |
Now that the Context is available, the same data can be accessed more cleanly:
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$this->context->language->id; |
What is stored by the Context?
...
A few common replacements:
Static shortcuts in
FrontController
subclasses are deprecated:Code Block $id_cart = self::cart->id;
...is to be replaced with...
Code Block $id_cart = $this->context->cart->id;
Do not recreate an object that already exists:
Code Block $language = new Language($cookie->id_lang); $iso_code = $language->iso_code;
...is to be replaced with...
Code Block $iso_code = $this->context->language->iso_code;
More examples of Context use
...
Old way | New way |
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$cookie->id_lang; | $this->context->language->id; |
if ($cookie->isLogged()) | if ($this->context->customer->isLogged()) |
if ($cookie->isLoggedBack()) | if ($this->context->employee->isLoggedBack(); |
$cart->getProducts(); | $this->context->cart->getProducts(); |
$language = new Language($cookie->id_lang); | $this->context->language->iso_code; |
new Currency($cookie->id_lang); | $this->context->currency; |
$defaultCountry->id_zone; | $this->context->country->id_zone; |
new Link(); | $this->context->link; |
$smarty->assign(...); | $this->context->smarty->assign(...); |