PHP5 - OOP - Polymorphism - Help me to rewrite this simple switch
Assuming i have this classic switch, i know that when we are building classes is not a good practice use the switch method, so, how i can rebuild this into a class without using switch but Polymorphism and i would like to understand the approach.
/**
* globals below are holding unique id
* $Franklin['Franklin_id'] ,
* $Granny_Smith['Granny_Smith_id'] ,
* etc etc...
*/
global $Fuji, $Gala, $Franklin, $Granny_Smith;
switch($Apple) {
case 'Fuji':
$Color = 'Yellowish green';
$Size = 'medium';
$Origin = 'Japan';
$Season = 'October - January';
$AppleId = $Fuji['Fuji_id'];
break;
case 'Gala':
$Color = 'yellow';
$Size = 'medium';
$Origin = 'New Zealand';
$Season = 'October - January';
$AppleId = $Gala['Gala_id'];
break;
case 'Franklin':
$Color = 'Well-colored';
$Size = 'medium';
$Origin = 'Ohio';
$Season = 'October';
$AppleId = $Franklin['Franklin_id'];
break;
case 'Granny_Smith':
$Color = 'Green';
$Size = 'medium';
$Origin = 'Australia';
$Season = 'October - December';
$AppleId = $Granny_Smith['Granny_Smith_id'];
break;
}
then i would like to be able to use it something like this
$AppleProps = new getApple('Granny_Smith'); // $AppleProps->Color, etc etc
Thank you in advance and hope this can help someone else.
Kind Regards
Luca
- thank's to http://w开发者_开发百科ww.allaboutapples.com/ for Apples Informations ;)
If you really want to use OO for this, then what you should do is create an appleFactory class, then have separate classes for each kind of apple...
class appleFactory
{
public static function getApple( $name )
{
$className = $name.'_apple';
return new $className( );
}
}
class fuji_apple
{
public function __construct( )
{
$this->color = 'Yellowish green';
$this->size = 'medium';
$this->origin = 'Japan';
$this->season = 'October - January';
$this->appleId = $Fuji['Fuji_id'];
}
}
class gala_apple
{
public function __construct( )
{
$this->color = 'Yellow';
$this->size = 'medium';
$this->origin = 'New Zealand';
$this->season = 'October - January';
$this->appleId = $Gala['Gala_id'];
}
}
Then use it like so...
$fuji = appleFactory::get( 'fuji' );
$gala = appleFactory::get( 'gala' );
I'm not complete sure what your IDs mean, but this code gives you an AppleFactory that will "stamp" each new apple with a unique ID.
class AppleFactory {
static $id = 0;
static public function getApple($className) {
$apple = new $className();
$apple->id = self::$id++;
return $apple;
}
}
class Apple {
public $id;
public $color;
public $size;
public $origin;
public $season;
}
class GrannySmith extends Apple {
public function __construct() {
$this->color = 'Green';
$this->size = 'medium';
$this->origin = 'Australia';
$this->season = 'October - Desember';
}
}
$a = AppleFactory::getApple('GrannySmith');
print_r($a);
There's no need for object-orientation here. But the switch
can be replaced by a much simpler construct. If you use a data array, you can even skip the function:
$apple_data = array(
'Fuji' => array(
'Color' => 'Yellowish green';
'Size' => 'medium';
'Origin' => 'Japan';
'Season' => 'October - January';
'AppleId' = 1234567890,
),
'Gala' => array(
'Color' => 'yellow';
'Size' => 'medium';
'Origin' => 'New Zealand';
'Season' => 'October - January';
'AppleId' => 1234598760,
),
...
);
To access the attributes just use:
$id = $apple_data["Granny_Smith"]["AppleId"]
Or if you really want all those local variables:
extract($apple_data["Granny_Smith"]);
// creates $Color, $Size, $Origin, $Season, $AppleId in local scope
If you really want the object-syntax, then try:
$AppleProps = new ArrayObject($apple_data["Fuji"], 2);
print $AppleProps->Color;
But since the apples are not doing anything, you probably don't want to create a class or real objects for them. (Damn apples. Just sitting there and doing nothing.)
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