README

ActiveRecord Collection Extension for Yii 2

This extension provides a generic data collection as well as a collection for the ActiveRecord DB layer of Yii 2.

Development is currently in experimental state. It is not ready for production use and may change significantly.

For license information check the LICENSE-file.

Documentation is at docs/guide/README.md.

Installation

The preferred way to install this extension is through composer.

Either run

php composer.phar require --prefer-dist laxity7/yii2-collection

or add

"laxity7/yii2-collection": "~1.0.0"

to the require section of your composer.json.

##Basic usage

Collection is a container for a set of items.

It provides methods for transforming and filtering the items as well as sorting methods, which can be applied using a chained interface. All these operations will return a new collection containing the modified data keeping the original collection as it was as long as containing objects state is not changed.

$collection = new Collection([1, 2, 3]);
echo $collection->map(function($i) { // [2, 3, 4]
    return $i + 1;
})->filter(function($i) { // [2, 3]
    return $i < 4;
})->sum(); // 5

The collection implements [[ArrayAccess]], [[Iterator]], and [[Countable]], so you can access it in the same way you use a PHP array. A collection however is read-only, you can not manipulate single items.

$collection = new Collection([1, 2, 3]);
echo $collection[1]; // 2
foreach($collection as $item) {
    echo $item . ' ';
} // will print 1 2 3

Configuration for ActiveRecord

To use this extension, you have to attach the yii\collection\CollectionBehavior to the ActiveQuery instance of your ActiveRecord classes by overriding the find() method:

/**
 * {@inheritdoc}
 * @return \yii\db\ActiveQuery|\yii\collection\CollectionBehavior
 */
public static function find()
{
    $query = parent::find();
    $query->attachBehavior('collection', \yii\collection\CollectionBehavior::class);
    return $query;
}