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This document describes the programming style and best practices used in Blesta. Programmers wishing to certify their plugin, module, or gateway, with the Marketplace must conform to these guidelines regardless of whether or not their source code is made available to end users.

Table of Contents

PHP File Formatting

Tags

PHP code must always begin with the long form opening tag. If a file contains only PHP code, the end tag may optionally be omitted from the end of the file.

<?php

?>

Indentation

Tabs should always be used for indentation. Spaces should never be used for indentation. We live in a world where IDEs can be configured to display tabs at variable lengths, so configure your tab width to what you feel comfortable with. This author prefers tabs to be represented as 4 spaces.

Line Length

Lines should be designed such that a reader can avoid horizontal scrolling, except in cases where scrolling offers improved readability over word-wrapping. As the resolution and width of monitors has increased the standard width of 80 characters (previously the width of a punch card) no longer holds any relevance. Use your best judgement to determine where lines should wrap.

EOL

Every line should terminate with a Unix-style line-feed (LF) character only. That is '\n', also known as hex value 0x0A. Do not use CRLF (Windows systems) or CR (Mac systems).

Character Encoding

All PHP files should be encoded using UTF-8, with no byte-order-mark (BOM).

 

Programming Style

Variables

Use logical and descriptive names for your variables. Variables used in iterating loops, such as $i, $j, $k, etc., are exceptions to this rule. Variables should contain only lowercase letters, underscores, and numbers, and should start with a letter. Values true, false, and null should always be lowercase.

Incorrect

$foo = 365; // not descriptive
$days_in_non_leap_year = 365; // too long
$_year_days = 365; // starts with an underscore

Correct

$year_days = 365;
$leap_year_days = 366;

Strings

Literals

Strings consisting of more than one character should be surrounded with double-quotes ("). Strings consisting of only a single character may be surrounded with single-quotes (').

$str = "This is a long string";
$chr = 'a';

Concatenation

Run-on Strings

A string whose length requires it to wrap multiple lines should be concatenated with the concatenation character (.) appended at the end of the line, with the carry-over line indented below it.

$str = "This is a string that needs to " .
    "wrap onto another line.";
Variable Substitution

When a variable needs to be added to a string the string should be broken open and concatenated together to improve readability.

$name = "Hefo Quent Esbit";
$str = "Hello " . $name . "! How are you?"

Arrays

Numerically Index Arrays

Each array element should be separated by a comma and a space character. If wrapping an array across multiple lines, subsequent lines should be indented.

Correct

$shapes = array("circle", "square", "triangle", "hexagon");
$colors = array(
    "red", "pink",
    "green", "purple"
);

Associative Arrays

Associative arrays should have a space before and after the => assignment. Array indexes should be quoted using single quotes ('). Short arrays can contain all elements on a single line, but it's recommend to set each index on its own line.

Correct

$blocks = array(
    'circle' => "red",
    'square' => "pink",
    'triangle' => "green",
    'hexagon' => "purple"
);

Multidimensional Arrays

Each array depth should be indented one level. The ending parenthesis of the array should be indented such that it aligns with the indent level of its defining index.

Correct

$polygons = array(
    'triangles' => array(
        "obtuse",
        "acute",
        "right"
    ),
    'quadrilaterals' => array(
        "square",
        "rhombus",
        "rectangle"
    )
);

Constants

Constants should always be capitalized.

Incorrect

define("myConstant", "some value");

Correct

define("MY_CONSTANT", "some value");

Statements

Blesta uses Compact Control Readability style. Each statement should begin on its own line. The exception to this rule is do-while.

Incorrect

if ($foo > $bar)
{
     echo "foo is greater";
} else 
{
    echo "bar is greater";
}

Correct

if ($foo > $bar) {
    echo "foo is greater";
}
else {
    echo "bar is greater";
}

$i = 5;
do {
    echo $i--;
} while ($i > 0);

Classes

Declaration

Class names should be CamelCased. Only a single class should appear in a file. Class file names should correlate to the class name, be lowercase, and use underscores to separate words. Class constructors should be named using the __construct() magic method.

Incorrect

my_class.php
<?php
// Class name starts with a lower case letter
class myClass {
    // Constructor should be named __construct()
    public function myClass() {
    }
}
?>

Correct

my_class.php
<?php 
class MyClass {
    public function __construct() {
    }
}
?>

Member Variables

All member variables should be declared at the top of the class, before any methods are declared. Variables must always declare their visibility using public, private, or protected.

Incorrect

<?php
class MyClass {
    // Can not use var, must use public, private, or protected
    var $foo;

    public function __construct() {
    }
    
    // Must be declared at the top of the class
    private $bar = "baz";
}
?>

Correct

<?php
class MyClass {
    public $foo;
    private $bar = "baz";

    public function __construct() {
    }
}
?>

Methods

Method names should begin with a lowercase letter and be camelCased. Type hinting should be used whenever possible, but must conform to PHP 5.1 syntax (i.e. only objects and arrays may be defined using type hints).

Incorrect

public function CalcDistance($time, $velocity) {
    return $time*$velocity;
}

Correct

public function calcDistance($time, $velocity) {
    return $time*$velocity;
}

Comments

There are three types of comments that may be used in PHP. They are block comments (/* */), inline comments (//), and shell comments (#).

Block Comments

Block comments are used for doc commenting and commenting out large sections of code. Blesta uses PHPDoc syntax for all doc comments. Block comments may not be used as a substitute for inline comments.

Incorrect

/*
This is a comment.
*/
if ($foo > $bar) {
    return $bar
}

Correct

/**
 * This is a doc block comment 
 */ 
function foo() {

}

Inline Comments

Inline comments should be used to clarify code. You are discouraged from using inline comments at the end of a line as this creates run-on lines and your comment is unlikely to be read.

Incorrect

/*
Calculate the circumference
*/
$c = 2*pi()*$r;

Correct, but discouraged

$c = 2*pi()*$r; // Calculate the circumference

Correct

// Calculate the circumference
$c = 2*pi()*$r;

Shell Comments

These comments should only be used to identify TODO comments.

Incorrect

# Calculate the circumference
$c = 2*pi()*$r;

Correct

<?php
class MyClass {
    #
    # TODO: Finish this class.
    #
}
?>
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