README.md

Collection

Collection is a set of useful wrapper classes for arrays, similar to Java Collection.

The current version comes with the ArrayList class, which can be used as wrapper for arrays. Furthermore you can implement the Comparable interface for elements of the ArrayList and the abstract class Comparator to sort the Elements in the ArrayList.

Installing Collection

The recommended way to install Collection is through Composer.

# Install Composer
curl -sS https://getcomposer.org/installer | php

Next, run the Composer command to install the latest stable version of Collection:

php composer.phar require seboettg/collection

After installing, you need to require Composer's autoloader:

require 'vendor/autoload.php';

You can then later update Collection using composer:

composer.phar update

Examples

Simple Usage

Initialize ArrayList

<?php
use Seboettg\Collection\ArrayList;
$list = new ArrayList(["a", "c", "h", "k", "j"]);
$map = new ArrayList([
    "c" => "cc",
    "b" => "bb",
    "a" => "aa"
]);

Get elements

for ($i = 0; $i < $list->count(); ++$i) {
    echo $list->get($i)." ";
}

This will output:

a c h k j 

ArrayList implements the ArrayAccess interface, so you can also access elements in an instance of ArrayList in exactly the same way as you access an element in arrays:

for ($i = 0; $i < $list->count(); ++$i) {
    echo $list[$i]." ";
}

Iterate ArrayList using foreach

foreach ($map as $key => $value) {
    echo "[".$key."] => ".$value."\n";
}

Output:

c => cc
b => bb
a => aa

Set, add or append Elements

//set element
$map->set("d", "dd");
//or
$map["d"] = "dd";
 
//add element
$map->add("d", "ddd")
print_r($map[$d]);
/*
output:
Array(
  0 => "dd",
  1 => "ddd"
)
*/

$list->append("z"); //append to the end of $list

remove, replace, clear

$map->remove("d"); //removes d from $map

$list->replace(["z", "y", "x"]); //replaces all elements by the specified

$list->clear(); //removes all elements of the list

Advanced Usage

Sorting an ArrayList

Implement the Comparable interface

<?php
namespace Vendor\App\Model;
use Seboettg\Collection\Comparable;
class Element implements Comparable
{
    private $attribute1;
    private $attribute2;
    
    //contructor
    public function __construct($attribute1, $attribute2)
    {
        $this->attribute1 = $attribute1;
        $this->attribute2 = $attribute2;
    }
    
    // getter
    public function getAttribute1() { return $this->attribute1; }
    public function getAttribute2() { return $this->attribute2; }
    
    //compareTo function
    public function compareTo(Comparable $b)
    {
        return strcmp($this->attribute1, $b->getAttribute1());
    }
}

Create a comparator class

<?php
namespace Vendor\App\Util;

use Seboettg\Collection\Comparator;
use Seboettg\Collection\Comparable;

class Attribute1Comparator extends Comparator
{
    public function compare(Comparable $a, Comparable $b)
    {
        if ($this->sortingOrder === Comparator::ORDER_ASC) {
            return $a->compareTo($b);
        }
        return $b->compareTo($a);
    }
}

Sort your list

<?php
use Seboettg\Collection\ArrayList;
use Seboettg\Collection\Collections;
use Seboettg\Collection\Comparator;
use Vendor\App\Util\Attribute1Comparator;
use Vendor\App\Model\Element;


$list = new ArrayList([
    new Element("b","bar"),
    new Element("a","foo"),
    new Element("c","foobar")
]);

Collections::sort($list, new Attribute1Comparator(Comparator::ORDER_ASC));

sort your list using a custom order

<?php
use Seboettg\Collection\Comparator;
use Seboettg\Collection\Comparable;
use Seboettg\Collection\ArrayList;
use Seboettg\Collection\Collections;
use Vendor\App\Model\Element;

//Define a custom Comparator
class MyCustomOrderComparator extends Comparator
{
    public function compare(Comparable $a, Comparable $b)
    {
        return (array_search($a->getAttribute1(), $this->customOrder) >= array_search($b->getAttribute1(), $this->customOrder)) ? 1 : -1;
    }
}

$list = new ArrayList([
    new Element("a", "aa"),
    new Element("b", "bb"),
    new Element("c", "cc"),
    new Element("k", "kk"),
    new Element("d", "dd"),
]);

Collections::sort(
    $list, new MyCustomOrderComparator(Comparator::ORDER_CUSTOM, ["d", "k", "a", "b", "c"])
);

filter your list

$list = new ArrayList([
    new Element("a", "aa"),
    new Element("b", "bb"),
    new Element("c", "cc"),
    new Element("k", "kk"),
    new Element("d", "dd"),
]);

$newList = $list->filterByKeys([0, 2]); //returns new list containing 1st and 3rd element of $list

custom filter

$list = new ArrayList([
    new Element("a", "aa"),
    new Element("b", "bb"),
    new Element("c", "cc"),
    new Element("k", "kk"),
    new Element("d", "dd"),
]);

$arrayList = $list->filter(function (Element $elem) {
    return $elem->getAttribute2() === 'bb' || $elem->getAttribute2() === 'kk';
});

// $arrayList contains just the 2nd and the 4th element of $list

Contribution

Fork this Repo and feel free to contribute your ideas using pull requests.