Laravel: A Trait for friendship.

Friendship.php

<?php

namespace App\Traits;

use App\User;

trait Friendship
{
    public function solicitationsOfMine()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'user_id', 'friend_id')
            ->wherePivot('accepted', false)
            ->withTimestamps();
    }

    public function solicitationsOf()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'friend_id', 'user_id')
            ->wherePivot('accepted', false)
            ->withTimestamps();
    }

    public function friendsOfMine()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'user_id', 'friend_id')
            ->wherePivot('accepted', true)
            ->withTimestamps();
    }

    public function friendsOf()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'friend_id', 'user_id')
            ->wherePivot('accepted', true)
            ->withTimestamps();
    }

    public function getFriendsAttribute()
    {
        if ( ! array_key_exists('friends', $this->relations)) $this->loadFriends();

        return $this->getRelation('friends');
    }

    protected function loadFriends()
    {
        if ( ! array_key_exists('friends', $this->relations))
        {
            $friends = $this->mergeFriends();

            $this->setRelation('friends', $friends);
        }
    }

    protected function mergeFriends()
    {
        return $this->friendsOfMine->merge($this->friendsOf);
    }

    public function closeFriendsOfMine()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'user_id', 'friend_id')
            ->wherePivot('accepted', true)
            ->wherePivot('user_close', true)
            ->withTimestamps();
    }

    public function closeFriendsOf()
    {
        return $this->belongsToMany(User::class, 'friend_user', 'friend_id', 'user_id')
            ->wherePivot('accepted', true)
            ->wherePivot('friend_close', true)
            ->withTimestamps();
    }

    public function getCloseFriendsAttribute()
    {
        if ( ! array_key_exists('closeFriends', $this->relations)) $this->loadCloseFriends();

        return $this->getRelation('closeFriends');
    }

    protected function loadCloseFriends()
    {
        if ( ! array_key_exists('closeFriends', $this->relations))
        {
            $closeFriends = $this->mergeCloseFriends();

            $this->setRelation('closeFriends', $closeFriends);
        }
    }

    protected function mergeCloseFriends()
    {
        return $this->closeFriendsOfMine->merge($this->closeFriendsOf);
    }
}