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Coding Standards

CakePHP developers will use the following coding standards.

It is recommended that others developing CakeIngredients follow the same standards.

You can use the CakePHP Code Sniffer to check that your code follows required standards.

Adding New Features

No new features should be added, without having their own tests – which should be passed before committing them to the repository.

Indentation

One tab will be used for indentation.

So, indentation should look like this:

// base level
    // level 1
        // level 2
    // level 1
// base level

Or:

$booleanVariable = true;
$stringVariable = 'moose';
if ($booleanVariable) {
    echo 'Boolean value is true';
    if ($stringVariable === 'moose') {
        echo 'We have encountered a moose';
    }
}

Line Length

It is recommended to keep lines at approximately 100 characters long for better code readability. Lines must not be longer than 120 characters.

In short:

  • 100 characters is the soft limit.
  • 120 characters is the hard limit.

Control Structures

Control structures are for example “if”, “for”, “foreach”, “while”, “switch” etc. Below, an example with “if”:

if ((expr_1) || (expr_2)) {
    // action_1;
} elseif (!(expr_3) && (expr_4)) {
    // action_2;
} else {
    // default_action;
}
  • In the control structures there should be 1 (one) space before the first parenthesis and 1 (one) space between the last parenthesis and the opening bracket.
  • Always use curly brackets in control structures, even if they are not needed. They increase the readability of the code, and they give you fewer logical errors.
  • Opening curly brackets should be placed on the same line as the control structure. Closing curly brackets should be placed on new lines, and they should have same indentation level as the control structure. The statement included in curly brackets should begin on a new line, and code contained within it should gain a new level of indentation.
  • Inline assignments should not be used inside of the control structures.
// wrong = no brackets, badly placed statement
if (expr) statement;

// wrong = no brackets
if (expr)
    statement;

// good
if (expr) {
    statement;
}

// wrong = inline assignment
if ($variable = Class::function()) {
    statement;
}

// good
$variable = Class::function();
if ($variable) {
    statement;
}

Ternary Operator

Ternary operators are permissible when the entire ternary operation fits on one line. Longer ternaries should be split into if else statements. Ternary operators should not ever be nested. Optionally parentheses can be used around the condition check of the ternary for clarity:

// Good, simple and readable
$variable = isset($options['variable']) ? $options['variable'] : true;

// Nested ternaries are bad
$variable = isset($options['variable']) ? isset($options['othervar']) ? true : false : false;

View Files

In view files (.ctp files) developers should use keyword control structures. Keyword control structures are easier to read in complex view files. Control structures can either be contained in a larger PHP block, or in separate PHP tags:

<?php
if ($isAdmin):
    echo '<p>You are the admin user.</p>';
endif;
?>
<p>The following is also acceptable:</p>
<?php if ($isAdmin): ?>
    <p>You are the admin user.</p>
<?php endif; ?>

Comparison

Always try to be as strict as possible. If a none strict test is deliberate it might be wise to comment it as such to avoid confusing it for a mistake.

For testing if a variable is null, it is recommended to use a strict check:

if ($value === null) {
      // ...
}

The value to check against should be placed on the right side:

// not recommended
if (null === $this->foo()) {
    // ...
}

// recommended
if ($this->foo() === null) {
    // ...
}

Function Calls

Functions should be called without space between function’s name and starting bracket. There should be one space between every parameter of a function call:

$var = foo($bar, $bar2, $bar3);

As you can see above there should be one space on both sides of equals sign (=).

Method Definition

Example of a method definition:

public function someFunction($arg1, $arg2 = '') {
    if (expr) {
        statement;
    }
    return $var;
}

Parameters with a default value, should be placed last in function definition. Try to make your functions return something, at least true or false, so it can be determined whether the function call was successful:

public function connection($dns, $persistent = false) {
    if (is_array($dns)) {
        $dnsInfo = $dns;
    } else {
        $dnsInfo = BD::parseDNS($dns);
    }

    if (!($dnsInfo) || !($dnsInfo['phpType'])) {
        return $this->addError();
    }
    return true;
}

There are spaces on both side of the equals sign.

Typehinting

Arguments that expect objects or arrays can be typehinted:

/**
 * Some method description.
 *
 * @param Model $Model The model to use.
 * @param array $array Some array value.
 * @param bool $boolean Some boolean value.
 */
public function foo(Model $Model, array $array, $boolean) {
}

Here $Model must be an instance of Model and $array must be an array.

Note that if you want to allow $array to be also an instance of ArrayObject you should not typehint as array accepts only the primitive type:

/**
 * Some method description.
 *
 * @param array|ArrayObject $array Some array value.
 */
public function foo($array) {
}

Method Chaining

Method chaining should have multiple methods spread across separate lines, and indented with one tab:

$email->from('foo@example.com')
    ->to('bar@example.com')
    ->subject('A great message')
    ->send();

Commenting Code

All comments should be written in English, and should in a clear way describe the commented block of code.

Comments can include the following phpDocumentor tags:

PhpDoc tags are very much like JavaDoc tags in Java. Tags are only processed if they are the first thing in a DocBlock line, for example:

/**
 * Tag example.
 *
 * @author this tag is parsed, but this @version is ignored
 * @version 1.0 this tag is also parsed
 */
/**
 * Example of inline phpDoc tags.
 *
 * This function works hard with foo() to rule the world.
 *
 * @return void
 */
function bar() {
}

/**
 * Foo function.
 *
 * @return void
 */
function foo() {
}

Comment blocks, with the exception of the first block in a file, should always be preceded by a newline.

Variable Types

Variable types for use in DocBlocks:

Type
Description
mixed
A variable with undefined (or multiple) type.
int
Integer type variable (whole number).
float
Float type (point number).
bool
Logical type (true or false).
string
String type (any value in ” ” or ‘ ‘).
null
Null type. Usually used in conjunction with another type.
array
Array type.
object
Object type. A specific class name should be used if possible.
resource
Resource type (returned by for example mysql_connect()). Remember that when you specify the type as mixed, you should indicate whether it is unknown, or what the possible types are.
callable
Callable function.

You can also combine types using the pipe char:

int|bool

For more than two types it is usually best to just use mixed.

When returning the object itself, e.g. for chaining, one should use $this instead:

/**
 * Foo function.
 *
 * @return $this
 */
public function foo() {
    return $this;
}

Including Files

include, require, include_once and require_once do not have parentheses:

// wrong = parentheses
require_once('ClassFileName.php');
require_once ($class);

// good = no parentheses
require_once 'ClassFileName.php';
require_once $class;

When including files with classes or libraries, use only and always the require_once function.

PHP Tags

Always use long tags (<?php ?>) Instead of short tags (<? ?>).

Naming Convention

Functions

Write all functions in camelBack:

function longFunctionName() {
}

Classes

Class names should be written in CamelCase, for example:

class ExampleClass {
}

Variables

Variable names should be as descriptive as possible, but also as short as possible. Normal variables should start with a lowercase letter, and should be written in camelBack in case of multiple words. Variables referencing objects should start with a capital letter, and in some way associate to the class the variable is an object of. Example:

$user = 'John';
$users = array('John', 'Hans', 'Arne');

$Dispatcher = new Dispatcher();

Member Visibility

Use PHP5’s private and protected keywords for methods and variables. Additionally, protected method or variable names start with a single underscore (_). Example:

class A {
    protected $_iAmAProtectedVariable;

    protected function _iAmAProtectedMethod() {
       /* ... */
    }
}

Private methods or variable names start with double underscore (__). Example:

class A {
    private $__iAmAPrivateVariable;

    private function __iAmAPrivateMethod() {
        /* ... */
    }
}

Try to avoid private methods or variables, though, in favor of protected ones. The latter can be accessed or modified by subclasses, whereas private ones prevent extension or re-use. Private visibility also makes testing much more difficult.

Example Addresses

For all example URL and mail addresses use “example.com”, “example.org” and “example.net”, for example:

The “example.com” domain name has been reserved for this (see RFC 2606) and is recommended for use in documentation or as examples.

Files

File names which do not contain classes should be lowercased and underscored, for example:

long_file_name.php

Casting

For casting we use:

Type
Description
(bool)
Cast to boolean.
(int)
Cast to integer.
(float)
Cast to float.
(string)
Cast to string.
(array)
Cast to array.
(object)
Cast to object.

Please use (int)$var instead of intval($var) and (float)$var instead of floatval($var) when applicable.

Constants

Constants should be defined in capital letters:

define('CONSTANT', 1);

If a constant name consists of multiple words, they should be separated by an underscore character, for example:

define('LONG_NAMED_CONSTANT', 2);