PHP Base Class Implementation with Iterator

This is a class definition for a base class which can be extended.

Features

  • Attributes are defined dynamically
  • Iteration is implemented, to allow the use of foreach
  • Attribute validation is included
  • Uses array_fill_keys if it is available, otherwise gracefully degrades to use a foreach loop
  • Allows attribute assignment with an associative array

Base Class Definition

PHP:

require_once 'include/common.php';
 
class Base Implements Iterator
{
        /**      Location for overloaded data.  */
        protected $data = array();
 
        public function __construct($attribute_names=null,$attribute_values=null)
        {
                if ($attribute_names!==null)
                {
                        if (function_exists(array_fill_keys))
                                $this->data=array_fill_keys($attribute_names,'');
                        else
                                foreach ($attribute_names as $v)
                                        $this->data[$v]='';
                        if ($attribute_values!==null)
                                foreach ($attribute_values as $k => $v)
                                        $this->$k=$v;
                }
                else
                        if (get_class($this)!=='Base')
                                halt(FAIL_CLASS_HAS_NO_ATTRIBUTES,get_class($this).' class has no attributes');
        }
 
        public function __set($name,$value)
        {
                if (array_key_exists($name,$this->data))
                        $this->data[$name]=$value;
                else
                        halt(FAIL_INVALID_ATTRIBUTE,get_class($this).' invalid attribute '.$name);
        }
 
        public function __get($name)
        {
                if (array_key_exists($name,$this->data))
                        return($this->data[$name]);
                else
                        return null;
        }
 
        public function __isset($name)
        {
                return isset($this->data[$name]);
        }
        public function rewind()
        {
                return reset($this->data);
        }
 
        public function current()
        {
                return current($this->data);
        }
 
        public function key()
        {
                return key($this->data);
        }
 
        public function next()
        {
                return next($this->data);
        }
 
        public function valid()
        {
                return current($this->data)!==false;
        }
 
 
        public function __destruct()
        {
        }
}

Extension Class

PHP:

class User extends Base
{
        public function __construct($aArgs=null)
        {
                bsBase::__construct(array(
                        'userID','roleName','userName',
                        'firstName','middleName','lastName','loginName',
                        'password','email','contactPhone'),$aArgs);
        }
 
        function __destruct()
        {
        }
}

Object Instantiation

PHP:

/* Create a new user, with the userID set to 1 */
$oUser=new User(array('userID'=>1));
$oUser->firstName='John';
foreach ($oUser as $k => $v)
  echo $k.' -> '.$v.PHP_EOL;

This post courtesy of Lyrix, Inc. / Mobiso

Categories: PHP
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