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PrestaShop development standard



Variable names

  1. Corresponding to data from databases: $my_var.
  2. Corresponding to algorithm: $my_var.
  3. The visibility of a member variable does not affect its name: private $my_var.


  1. There should be a space between variable and operators:
$my_var = 17;
$a = $b;


  1. "+", "-", "*", "/", "=" and any combination of them (e.g. "/=") need a space between their left and right members.

    $a + 17;
    $result = $b / 2;
    $i += 34;
  2. "." does not have a space between its left and right members.

    echo $a.$b;
    $c = $d.$this->foo();


    For performance reasons, please do not overuse concatenation.

  3. ".=" needs a space between its left and right members.

    $a .= 'Debug';


  1. if, elseif, while, for: need a space between the if keyword and the bracket ().

    if (<condition>)
    while (<condition>)
  2. When a combination of if and else is used and both can return a value, the else has to be avoided.

    if (<condition>)
    	return false;
    return true;


    We recommend one return per method / function

  3. When a method/function returns a boolean and the current method/function's returned value depends on it, the if statement has to be avoided

    public aFirstMethod()
    	return $this->aSecondMethod();
  4. Tests must be grouped by "entity"

    if ($price AND !empty($price))
    if (!Validate::$myObject OR $myObject->id === NULL)


  1. The visibility must be defined every time, even when it is a public method.
  2. The order of the method properties should be: visibility static function functionName().

    private static function foo()

Method / Function names

  1. Method and function names always use CamelCase: begin with a lowercase character and each following words must begin with an uppercase character.

    public function myExampleMethodWithALotOfWordsInItsName()
  2. Braces introducing method code have to be preceded by a carriage return.

    public function myMethod($arg1, $arg2)
  3. Method and function names must be explicit, so function names such as b() or ef()are completely forbidden.


    The only exceptions are the translation function (called l()) and debug the functions (named p() and d()).


Commas have to be followed (and not preceded) by a space.

protected function myProtectedMethod($arg1, $arg2, $arg3 = null)

Objects / Classes

  1. Object name must be singular.

    class Customer
  2. Class name must follow the CamelCase practice, except that the first letter is uppercase.

    class MyBeautifulClass


  1. Define names must be written in uppercase
  2. Define names have to be prefixed by "PS_" inside the core and module

    define('PS_DEBUG', 1);
    define('PS_MODULE_NAME_DEBUG', 1);
  3. Define names does not allow none alphabetical characters. Except "_".


All keywords have to be lowercase: as, case, if, echo, null.


Constants must be uppercase, except for "true", "false" and "null" which must be lowercase: ENT_NOQUOTE, true.

Configuration variables

Configuration variables follow the same rules as defined above.


Strings have to be surrounded by simple quotes, never double ones.

echo 'Debug';
$myObj->name = 'Hello '.$name;


  1. Inside functions and methods, only the "//" comment tag is allowed.
  2. After the "//" comment marker, a space is required: // Comment.

    // My great comment
  3. The "//" comment marker is tolerated at the end of a code line.

    $a = 17 + 23; // A comment inside my example function
  4. Outside of functions and methods, only the "/" and "/" comment markers are allowed.

    /* This method is required for compatibility issues */
    public function foo()
    	// Some code explanation right here
  5. PHP Doc comment block is required before the declaration of the method.

     * Return field value if possible (both classical and multilingual fields)
     * Case 1: Return value if present in $_POST / $_GET
     * Case 2: Return object value
     * @param object $obj Object
     * @param string $key Field name
     * @param integer $id_lang Language id (optional)
     * @return string
    protected function getFieldValue($obj, $key, $id_lang = NULL)

    For more informations

Return values

  1. The return statement does not need brackets, except when it deals with a composed expression.

    return $result;
    return ($a + $b);
    return (a() - b());
    return true;
  2. The return statement can be used to break out of a function.



Function call preceded by a "@" is forbidden but beware with function / method call with login / password or path arguments.

// In the following example, we put a @ for security reasons


  1. There must be an empty line after the PHP opening tag.

  2. The PHP ending tag is forbidden


  1. The tabulation character ("
    t") is the only indentation character allowed.
  2. Each indentation level must be represented by a single tabulation character.

    function foo($a)
    	if ($a == null)
    		return false;


  1. The arraykeyword must not be followed by a space.

    array(17, 23, 42);
  2. When too much data is inside an array, the indentation has to follow the following.

    $a = array(
    	36 => $b,
    	$c => 'foo',
    	$d => array(17, 23, 42),
    	$e => array(
    		0 => 'zero',
    		1 => $one


Braces are prohibited when they only define one instruction or a combination of statements.

if (!$result)
	return false;

for ($i = 0; $i < 17; $i++)
	if ($myArray[$i] == $value)
		$result[] = $myArray[$i];


  1. All user's data (data entered by users) has to be cast.

    $data = Tools::getValue('name');
    $myObject->street_number = (int)Tools::getValue('street_number');
  2. All method/function's parameters must be typed (when Array or Object) when received.

    public myMethod(Array $var1, $var2, Object $var3)
  3. For all other parameters, they have to be cast each time they are used, except when they are sent to other methods/functions.

    protected myProtectedMethod($id, $text, $price)
    	$this->id = (int)$id;
    	$this->price = (float)$price;
    	$this->callMethod($id, $price);


  1. Source code lines are limited to 150 characters.
  2. Functions and methods lines are limited to 80 characters. Functions must have a good reason to have an overly long name: keep it to the essential!


  1. It is forbidden to use a ternary into another ternary (such as echo ((true ? 'true' : false) ? 't' : 'f');).
  2. We recommend the use of && and || into your conditions: echo ('X' == 0 && 'X' == true
  3. Please don't use reference parameters (such as {{function is_ref_to(&$a, &$b) { ... }}}).


Table names

  1. Table names must begin with the PrestaShop "DB_PREFIX" prefix.

    ... FROM `'. _DB_PREFIX_.'customer` ...
  2. Table names must have the same name as the object they reflect: "ps_cart".
  3. Table names have to stay singular: "ps_order".
  4. Language data have to be stored in a table named exactly like the object's table, and with the "_lang" suffix "ps_product_lang".

SQL query

  1. Keywords must be written in uppercase.

    SELECT `firstname`
    FROM `'. _DB_PREFIX_.'customer`
  2. Back quotes ("`") must be used around SQL field names and table names.

    SELECT p.`foo`, c.`bar`
    FROM `'. _DB_PREFIX_.'product` p, `'. _DB_PREFIX_.'customer` c
  3. Table aliases have to be named by taking the first letter of each word, and must be lowercase.

    SELECT p.`id_product`, pl.`name`
    FROM `'. _DB_PREFIX_.'product` p
    NATURAL JOIN `'. _DB_PREFIX_.'product_lang` pl
  4. When conflicts between table aliases occur, the second character has to be also used in the name.

    SELECT ca.`id_product`, cu.`firstname`
    FROM `'.DB_PREFIX.'cart` ca, `'. _DB_PREFIX_.'customer` cu
  5. Indentation has to be done for each clause

    $query = 'SELECT pl.`name`
    FROM `'.PS_DBP.'product_lang` pl
    WHERE pl.`id_product` = 17';
  6. It is forbidden to make a JOIN in a WHERE clause.

Installing the code validator

This is a brief tutorial on how to install a code validator on your PC and use it to validate your files. The code validator uses PHP CodeSniffer, which is a PEAR package ( The PrestaShop code standard was created specifically for CodeSniffer, using many rules taken from existing standards, with added customized rules in order to better fit our project.

You can download the PrestaShop code standard using Git: (you must perform this step before going any further with this tutorial).

Eclipse integration

Quick links:

If you use Eclipse, you can integrate code validation within the text editor using a plugin, which is very easy to install:

The configuration of the plugin is also very simple: In the list of available packages, only choose PHP CodeSniffer and PEAR if you do not yet have them.

You will then have to add the PrestaShop code standard to the Eclipse preferences: go to "PHP Tools" and choose the PS standard that you downloaded earlier (see link above).

If the file does not automatically validate, as it should, you can configure this in the "Preferences" menu, "Validation" option. Otherwise, just right-click on the folder/file in the file-tree, and choose "PHP Tools" in the contextual menu (which you can also be set as a shortcut).

Command line (Linux)

You do not have to use Eclipse to use PHP CodeSniffer, you can also install it so that it can be called from the command line.

  1. Install PEAR:
    $> apt-get install php-pear
  2. Install PHP CodeSniffer in PEAR:
    $> pear install PHP_CodeSniffer
  3. Add the PrestaShop standard that you downloaded from SVN earlier, and place it in PHP CodeSniffer's "Standards" folder.
    $> git clone /usr/share/php/PHP/CodeSniffer/Standards/Prestashop
  4. Launch PHP CodeSniffer
    $> phpcs --config-set default_standard Prestashop

Using the program

The various options for this command are well explained in its documentation. For now, here is the easy way to launch it:

$> phpcs --standard=/path/to/norm/Prestashop /folder/or/fileToCheck

In order to only display errors, not warnings:

$> phpcs --standard=/path/to/norm/Prestashop --warning-severity=99 /folder/or/fileToCheck

If you have already manually installed PHP CodeSniffer, the program should be in PEAR's "scripts" folder.

Windows users: although the phpcs.bat file should be in that "scripts" folder, you might have to edit it in order for it to work properly (replace the paths with yours):

path/to/php.exe -d auto_apprend_file="" -d auto_prepend_file -d include_path="path/to/PEAR/" path/to/pear/scripts/phpcs

Integrating the program to Eclipse's console (optional)

  1. Click on the "External tools" button in the icon bar (a green arrow pointing at a small red folder).
  2. Click on the "External tools configuration" tab.
  3. Double-click on "Program" in order to create a configuration:
    1. Location: path to the phpcs program (or phpcs.bat for Windows users).
    2. Arguments: the arguments for the command line, for instance --standard=Prestashop.
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