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PrestaShop uses it for various functionalities, like the Store Locator. It is also used by some modules, as well as the pearxmlparse library. The File information extension is used to find out the file type of uploaded files. Logging into PrestaShop administration panel (back office) can be problematic. Especially the first time. Some difficulty can be caused by PrestaShop, because log in link is not just your-shop.co/admin but url is modified due to safety reasons.
Table of content
Consistency is important, even more so when writing open-source code, since the code belongs to millions of eyeballs, and bug-fixing relies on these teeming millions to actually locate bugs and understand how to solve it.
This is why, when writing anything for PrestaShop, be it a theme, a module or a core patch, you should strive to follow the following guidelines. They are the ones that the PrestaShop developers adhere to, and following them is the surest way to have your code be elegantly integrated in PrestaShop.
In short, having code consistency helps keeping the code readable and maintainable.
If use an IDE, you can use the CodeSniffer code validator to help you write better code.
PHP
Variable names
Just like class, method and function names, variable names should be written in English so as to be readable to as many people as possible.
Use lowercase letters, and separate words using underscores. Do not ever use CamelCase.
- Corresponding to data from databases:
$my_var
. - Corresponding to algorithm:
$my_var
. - The visibility of a member variable does not affect its name:
private $my_var
.
Assignments
- There should be a space between variable and operators:
Operators
'
+
', '-
', '*
', '/
', '=
' and any combination of them (e.g. '/=
') need a space between their left and right members.'
.
' does not have a space between its left and right members.Recommendation
For performance reasons, please do not overuse concatenation.
'
.=
' needs a space between its left and right members.When testing a boolean variable, do not use a comparison operator, but directly use the value itself, or the value prefixed with an exclamation mark:
Statements
if
,elseif
,while
,for
: need a space between theif
keyword and the parentheses()
.When a combination of
if
andelse
is used and both can return a value, theelse
statement has to be omitted.Recommendation
We recommend to use only one
return
statement per method/function.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.Tests must be grouped by entity.
Visibility
- The visibility must be defined every time, even when it is a public method.
The order of the method properties should be:
visibility static function functionName()
.
Method / Function names
Method and function names always use CamelCase: begin with a lowercase character and each following words must begin with an uppercase character.
Braces introducing method code have to be preceded by a carriage return.
Method and function names must be explicit, so function names such as
b()
oref()
are completely forbidden.Exceptions
The only exceptions are the translation function (called
l()
) and the debug functions (namedp()
andd()
).
Enumeration
Commas have to be followed (and not preceded) by a space.
Objects / Classes
Object name must be singular.
Class name must follow the CamelCase practice, except that the first letter is uppercase.
Constants
- Constant names must be written in uppercase, except for 'true', 'false' and 'null' which must be lowercase:
ENT_NOQUOTE
,true
. Constant names have to be prefixed with '
PS_
' inside the core and module.- Constant names should only use alphabetical characters and '_'.
Keywords
All keywords have to be lowercase: as, case, if, echo, null
.
Configuration variables
Configuration variables follow the same rules as defined above.
Strings
Strings have to be surrounded by simple quotes, never double ones.
Comments
- Inside functions and methods, only the '
//
' comment tag is allowed. After the '
//
' comment marker, a space is required:The '
//
' comment marker is tolerated at the end of a code line.Outside of functions and methods, only the '
/*
' and '*/
' comment markers are allowed.A phpDoc comment block is required before the declaration of the method.
For more informations
For more information about the PHP Doc syntax: http://manual.phpdoc.org/HTMLSmartyConverter/HandS/phpDocumentor/tutorial_tags.pkg.html.
Return values
The
return
statement does not need brackets, except when it deals with a composed expression.The
return
statement can be used to break out of a function.
Call
Performing a function call preceded by a '@
' is forbidden, but beware of function/method call with login/password or path arguments.
Tags
There must be an empty line after the PHP opening tag.
- The PHP closing tag is forbidden at the end of a file.
Indentation
- The tabulation character ('
t
') is the only indentation character allowed. Each indentation level must be represented by a single tabulation character.
Array
The
array
keyword must not be followed by a space.When too much data is inside an array, the indentation has to be as follows:
Block
Braces are prohibited when they only define one instruction or a combination of statements.
Security
All users' data (data entered by users) has to be cast.
getValue()
does not protect your code from hacking attempts (SQL injections, XSS flaws and CRSF breaches). You still have to secure your data yourself.
One PrestaShop-specific securization method ispSQL($value)
: it helps protect your database against SQL injections.All method/function's parameters must be typed (when
Array
orObject
) when received.For all other parameters, they have to be cast each time they are used, except when they are sent to other methods/functions.
Limitations
- Source code lines are limited to 150 characters wide.
- 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!
Other
- It is forbidden to use a ternary into another ternary, such as
echo ((true ? 'true' : false) ? 't' : 'f');
. - We recommend the use of
&&
and||
into your conditions instead ofAND
andOR
:echo ('X' 0 && 'X' true)
. Please refrain from using reference parameters, such as:
SQL
Table names
Table names must begin with the PrestaShop '
_DB_PREFIX_
' prefix.- Table names must have the same name as the object they reflect: '
ps_cart
'. - Table names have to stay singular: '
ps_order
'. - 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
Keywords must be written in uppercase.
Back quotes ('
`
') must be used around SQL field names and table names.Table aliases have to be named by taking the first letter of each word, and must be lowercase.
When conflicts between table aliases occur, the second character has to be also used in the name.
A new line has to be created for each clause.
- It is forbidden to make a
JOIN
in aWHERE
clause.
Installing the code validator (PHP CodeSniffer)
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 (http://pear.php.net/package/PHP_CodeSniffer/). 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: https://github.com/PrestaShop/PrestaShop-norm-validator (you must perform this step before going any further with this tutorial).
/
Standards
folderPhpStorm integration
If you use PhpStorm (http://www.jetbrains.com/phpstorm/), follow these steps:
- Go to Settings -> Inspection -> PHP -> PHP Code Sniffer.
- Set the path to the
phpcs
executable. - Set the coding standard as 'PrestaShop' (which is only available if you did put in CodeSniffer's
/Standards
folder).
Integration to vim
Several plugins are available online. For instance, you can use this one: https://github.com/bpearson/vim-phpcs/blob/master/plugin/phpcs.vim
Put in your ~/.vim/plugin
folder.
Phpstorm Prestashop Plugin
You can add two shortcuts (for instance, F9 to display everything and Ctrl+F9 to hide warnings) in your .vimrc
file in normal and insert mode :
Command line (Linux)
You do not have to use PhpStorm to use PHP CodeSniffer, you can also install it so that it can be called from the command line.
- Install PEAR: http://pear.php.net/
$> apt-get install php-pear
- Install PHP CodeSniffer in PEAR: http://pear.php.net/package/PHP_CodeSniffer
$> pear install PHP_CodeSniffer
- Add the PrestaShop standard that you downloaded from SVN earlier, and place it in PHP CodeSniffer's 'Standards' folder.
$> git clone https://github.com/PrestaShop/PrestaShop-norm-validator
/usr/share/php/PHP/CodeSniffer/Standards/Prestashop
- Set the Prestashop standard as the default one
$> phpcs --config-set default_standard Prestashop
The various options for this command are well explained in its documentation. For now, here is the easy way to launch it:
In order to only display errors, not warnings:
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):
As a serious developer, you need to use versioning (or “revision control”) for your projects, in order to track changes to your files… and be able to travel back in time when a disaster happens. There are many CVS (Concurrent Versions System) available out there today, but Git is by far the most popular in 2015, and one of the most used in the Open Source world, right behind Subversion (svn).
PrestaShop moved from Subversion to Git more than 2 years ago, and made the switch from our own SVN server to GitHub, in order to make contribution easier for everyone. While doing so, we created a PrestaShop-specific .gitignore
file. A gitignore file is a must-have for any Git-versioned project, as it specifies intentionally untracked files that Git should ignore.
We created that file to help you better version your PrestaShop project. Let’s dive into that!
What to ignore
Generally, you shouldn’t version the following types of files:
- Temporary files (such as cache)
- Generated files (such as minified CSS or retrieved XMLs)
- Files with credentials or personal information (such as
settings.inc.php
)
Versioning core files
The first thing you need to decide is whether you want to keep track of the PrestaShop core files changes or not. If you’re using PrestaShop correctly, you shouldn’t modify core files to suit your needs – you should override the core classes in order to modify PrestaShop’s behavior.
If you don’t want to version the core files, you have to clone your repo then drop the PrestaShop files (from a stable release) into the folder.
But in my opinion, it is better to version core files.
Indeed, even if you don’t intend to modify the core files, you might have to apply specific patches. It’s always better to make sure that all your environments are exactly the same. This way, it’s much easier to deploy a new environment.
Even better: if you create a branch which tracks PrestaShop/PrestaShop (1.6 branch), you will be able to cherry-pick the patches you need.
With core files
If you host your project on GitHub, you can choose to initialize your project with a .gitignore
file.
We recently updated it, as a result you’ll get the file below (direct link):
Without core files
Debug Prestashop Phpstorm
If you don’t want to version the core files, PrestaShop contributor Adonis Karavokyros (also known as prestarocket) wrote this file instead:
Generate your own .gitignore
file with gitignore.io
gitignore.io is a great tool, based on the official GitHub/gitignore repo. You can generate a perfect .gitignore
file simply by listing the technologies you use in your project.
The website offers an easy-to-use interface, but if (like me) you want to show off, you can use the following Git alias in your configuration:
Next, the following command will generate a .gitignore
file inside the current directory containing these lines.
There you go! All of this should give a cleaner Git repository for your PrestaShop projects.
Do you have ideas on how to improve this? Do you use alternate files? Tell us your story in the comments!