Coding conventions

• Use under_score naming instead of camelCalse $my_var = 0; //correct $myVar = 0; //incorrect

• Use tabs for intendation, no spaces.

• Opening brackets should be on the same line separated with exactly one space. Closing brackets should be on their own line
  

  foreach (...) {
  	//statements here
  }
  </pre>
  
  

• Every statement block should be on brackets, even if it's only one statement. Exception is if that statement breaks the execution of the surrounding block.
  

  	foreach ($arr as $itm) {
  		$sum += $itm;
  	}
  if ($x === TRUE) {
  	$y = FALSE;
  }
  
  if ($x === TRUE)
  	break;
  
  if ($x === TRUE)
  	return;
  
  if ($x === TRUE)
  	throw new Exception(...);
  
  if ($x === TRUE) { //incorrect, braces are not needed here
  	continue;
  }
  
  

• Don't put spaces before and after a condition, expect it begins with "!". In this case you should put a space before and after the "!".
  

  	if ($x === TRUE) { //correct
  		//...
  	}
  if ( $x === TRUE ) { //incorrect
  	//...
  }
  
  if ( ! $x) { //correct
  	// ...
  }
  
  while (!$x) { //incorrect
  	// ...
  }
  
  

• Use boolean and null constants in uppercase
  

  	$x = TRUE; //correct
  	$x = true; //incorrect
  	$x = NULL; //correct
  

• When comparing against a constant value, the constant should be the first operator
  

  	if (NULL == $x) { //correct
  		//...
  	}
  if ($x == NULL) { //incorrect
  	//...
  }
  
  

• always use class type hints where possible. Never use the array type hint since this forbids you to pass ArrayObject instances as arguments.
  

  	function fn(MyClass $obj) { //correct
  		//...
  	}
  function fn2(array $arr) { //incorrect
  	//...
  }
  
  

• Try not to write lines longer than 80 characters.

• prefer using isset() over array_key_exists() (note that they don't work exactly the same way)

• Every line of a multi-line expression should start with an operator or comma:
  

  	if ($expression_1
  		&& $expression_2) { //correct
        //...
     }
  if ($expression_1 && //incorrect
  $expression_2) {
  //...
  }
  $obj->method1() //correct
  ->method2();
  $obj->method1()-> //incorrect
  method2();
  $obj->method($arrrrrrrrrrg1 //correct
  , $arg2);
  $obj->method($arrrrrrrrrrg1, //incorrect
  $arg2);
  

• local variables which are used to temporaly store a function or method result value should be named $rval or $result.
  

     function sum($arr) {
        $rval = 0;
        foreach ($arr as $itm) {
           $rval += $itm;
        }
        return $rval;
     }
  

• Class attributes should be separated with an empty line. Always use public access modifier for public members.
  

     public $attr1; //correct
  var $attr2; //incorrect
  public $attr3;
  public $attr4; //incorrect, missing empty line
  public $attr5; //the empty line is needed here too
  /**
  * @var string $attr6
  */
  public $attr6;
  function mymethod() { //incorrect, missing public modifier
  //...
  }
  

• The name of private and protected attributes should start with an underscore. Public attribue names should never start with an underscore.
  

     protected $_attr1; //correct
  protected $attr2; //incorrect
  public $attr3; //correct
  public $_attr4; //incorrect
  

• Don't write empty brackets when calling parameterless constructors
  

     $o = new MyClass; //correct
     $o = new MyClass(); //incorrect
  

• class naming conventions:
  - all classes must be in a namespace
  - all namespaces should be in lowercase
  - all classes of a library must be in a separate namespace under the cyclone namespace. A library can have at most 1 class out of its own namespace, and this class must be in the cyclone namespace (example: all classes of the DB library are in the cyclone\db namespace, except the cyclone\DB class).
  - the name of a class is recommended to have a meaningful name on its own too, without its namespace name.