NestedSetsTreeBehavior this is the connector between https://github.com/creocoder/yii2-nested-sets and https://github.com/wbraganca/yii2-fancytree-widget
The preferred way to install this extension is through composer.
Either run
php composer.phar require --prefer-dist wokster/yii2-nested-sets-tree-behavior "*"
or add
"wokster/yii2-nested-sets-tree-behavior": "*"
to the require section of your composer.json file.
Once the extension is installed, simply use it in your model :
'htmlTree'=>[
'class' => \wokster\treebehavior\NestedSetsTreeBehavior::className()
]use
SomeModel::findOne($id)->tree()to get array for fancytree-widget