n11t/abstract-collection

Abstract collection to handle object lists

1.2.0 2018-03-28 14:21 UTC

Requires (Dev)

• phpunit/phpunit: >=6.5 <7.0.0

MIT

• Nils Leonhardt

README

AbstractCollection

The AbstractCollection can be used to created typed lists.

Why?

With php7 the language improved a lot. But it's still not possible to use generics or typed arrays as parameter or return value. So we have to use a workaround.

With this abstract class you are able to build your own typed collection.

Usage

Extend from the AbstractCollection class and override the constructor.

class ProductCollection extends \N11t\AbstractCollection\AbstractCollection {

    public function __construct(Product ...$products)
    {
        $this->values = $products;
    }
}

Now you can type hint a collection of products everywhere in your code and be sure you get one.

Sampe Code

<?php
declare(strict_types=1);

require_once __DIR__ . '/vendor/autoload.php';

// Extend from AbstractCollection
class IntCollection extends \N11t\AbstractCollection\AbstractCollection {

    public function __construct(int ...$values)
    {
        $this->values = $values;
    }
}

// Type hint for collections instead of array
function write_ln(string $context, IntCollection $collection) {
    echo $context . PHP_EOL;

    // Iterate over
    foreach ($collection as $item) {
        echo $item . PHP_EOL;
    }
}

// Initialize typed collection.
$integer = [1,2,3,4,5];
$collection = new IntCollection(...$integer);

// Count collection
echo 'Collection count: ' . \count($collection) . PHP_EOL;

// Sort collection
write_ln('pre sort', $collection);
$collection->usort(function (int $a, int $b) {
    return $b <=> $a;
});
write_ln('post sort', $collection);

// Filter collection
$filteredCollection = $collection->filter(function(int $value, $key) {
   return $value % 2 === 0 || $key === 0;
}, \ARRAY_FILTER_USE_BOTH);

// Use toArray to get values
var_dump($collection->toArray());

Output

Collection count: 5
pre sort
1 2 3 4 5 
post sort
5 4 3 2 1 
array(3) {
  [0]=>
  int(5)
  [1]=>
  int(4)
  [3]=>
  int(2)
}