README

A reusable and robust behavior for managing many-to-many (M2M) relationships in Yii2 ActiveRecord using virtual attributes.

🧩 Inspired by the archived yii2tech/ar-linkmany package by Paul Klimov, now extended with modern improvements, full test coverage, and long-term support.

📦 Installation

composer require jonatas-sas/yii2-m2m-behavior

📚 Documentation

📘 English Docs
🇧🇷 Documentação em Português

🚀 Overview

Yii2 Many to Many Behavior helps you:

Manage M2M relations using virtual attributes (e.g. tagIds).
Automatically sync relations on insert, update, and delete.
Control deletion of junction table rows (deleteOnUnlink).
Add extra columns to junction records (e.g. timestamps or metadata).
Integrate smoothly into ActiveForm, GridView, and DetailView.

🛠 Example Usage (PHP 8.1+)

use yii\db\ActiveRecord;
use yii\db\ActiveQuery;
use odara\yii\behaviors\LinkManyToManyBehavior;

/**
 * @property int        $id
 * @property string     $name
 *
 * @property-read Tag[] $tags
 * @property int[]      $tagIds
 */
class Item extends ActiveRecord
{
    /**
     * @inheritdoc
     */
    public function behaviors()
    {
        return [
            'tags' => [
                'class' => LinkManyToManyBehavior::class,
                'relation' => 'tags',
                'referenceAttribute' => 'tagIds',
                'deleteOnUnlink' => true,
                'extraColumns' => [
                    'source' => 'admin',
                    'created_at' => static fn (): int => time(),
                ],
            ],
        ];
    }

    /**
     * Returns the relation between Item and Tag models.
     *
     * @return ActiveQuery
     */
    public function getTags(): ActiveQuery
    {
        return $this->hasMany(Tag::class, ['id' => 'tag_id'])
            ->viaTable('item_tag', ['item_id' => 'id']);
    }
}

Example Form Field

echo $form->field($model, 'tagIds')->checkboxList(
    Tag::find()
        ->select(['name', 'id'])
        ->indexBy('id')
        ->column()
);

🤝 Contributing

Found a bug or want to suggest an improvement?

Read the Contributing Guide
Follow PSR-12 and Yii2 coding practices

🛡 License

Yii2 Many to Many Behavior is released under the MIT License.

💙 Credits

Maintained by the Yii2 community.
Inspired by the Yii2Tech package and rebuilt with care for modern development.

jonatas-sas / yii2-m2m-behavior

Maintainers

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