Building an array from unknown object properties - php

Question

i'm trying to build an array from an Object in PHP. I only want certain properties from the object but I don;t know what they will be each time. The names of the properties I need are stored in an array. Here is how my code works currently:
// Hard-coded attributes 'colour' and 'size'
while ($objVariants->next())
{
$arrVariants[] = array
(
'pid' => $objVariants->pid,
'size' => $objVariants->size,
'colour' => $objVariants->colour,
'price' => $objVariants->price
);
}
Instead of hard coding the attributes (colour and size) I want to use variables, this is because it may not always be colour and size depending on what the user has set in the CMS. For example:
$arrVariantAttr = $this->getVariantAttr(); // Get the names of the custom variants and put them in an array e.g colour, size
while ($objVariants->next())
{
$arrVariants[] = array
(
'pid' => $objVariants->pid,
foreach($arrVariantAttr as $attr)
{
$attr['name'] => $objVariants-> . $attr['name']; // Get each variant out of the object and put into an array
}
'price' => $objVariants->price
);
}
The above code doesn't work, but hopefully it illustrates what i'm trying to do. Any help would be appreciated, thank you!

Answer 1

You could use get_object_vars() to get all variables of an object:
$arrVariants[] = get_object_vars($objVariants);
In order to exclude specific properties from the object you could do like this:
$arrVariants = get_object_vars($objVariants);
// array containing object properties to exclude
$exclude = array('name');
// walk over array and unset keys located in the exclude array
array_walk($arrVariants, function($val,$key) use(&$arrVariants, $exclude) {
if(in_array($key, $exclude)) {
unset($arrVariants[$key]);
}
});

Answer 2

You could create an array in the object containing the attributes:
$objVariants->attr['pid']
You can also use magic methods to make you object array like.

Answer 3

It sounds like what you really want is sub-classes or a Factory pattern.
For instance you could have a basic product object
class Product {
protected $_id;
protected $_sku;
protected $_name;
...
etc.
//getters and setters
etc.
}
... and then use sub-classes to extend that product
final class Book extends Product {
private $_isbn;
private $_language;
private $_numPages;
...
etc.
public function __construct() {
parent::__construct();
}
//getters and setters
etc.
}
That way your product types have all the attributes they need and you don't need to try and run around with an "attributes" array - though your CMS needs to be able to support product types (so that if someone wants to add a new book, the fields relevant to books appear in the CMS)... it's just a slightly more OO approach to the problem.
You could then factory pattern it; something like (a really basic example):
class ProductFactory {
const TYPE_BOOK = 'Book';
const TYPE_CD = 'CD';
const TYPE_DVD = 'DVD';
...
etc.
public static function createProduct($sProductType) {
if(class_exists($sProductType)) {
return new $sProductType();
}
else {
//throw an exception
}
}
}
You can then generate new products with something like:
$oWarAndPeace = ProductFactory::createProduct('Book')
or better yet:
$oWarAndPeace = ProductFactory::createProduct(ProductFactory::TYPE_BOOK)

Answer 4

Try something like this:
$arrVariants[] = Array(
'pid' => $objVariants->pid,
'price' => $objVariants->price
);
while( $objVariants->next() )
{
foreach( $arrVariantAttr as $attr )
{
end($arrVariants)[$attr['name']] = $objVariants->$attr['name'];
}
}