invoiceninja/app/models/EntityModel.php

<?php

class EntityModel extends Eloquent
{
	protected $softDelete = true;
	protected $hidden = ['id', 'created_at', 'deleted_at', 'updated_at'];

	public static function createNew($parent = false)
	{		
		$className = get_called_class();
		$entity = new $className();
		
		if (Auth::check()) {
			$entity->user_id = Auth::user()->id;
			$entity->account_id = Auth::user()->account_id;
		} else if ($parent) {
			$entity->user_id = $parent->user_id;
			$entity->account_id = $parent->account_id;
		} else {
			Utils::fatalError();
		}

		$lastEntity = $className::withTrashed()->scope(false, $entity->account_id)->orderBy('public_id', 'DESC')->first();

		if ($lastEntity)
		{
			$entity->public_id = $lastEntity->public_id + 1;
		}
		else
		{
			$entity->public_id = 1;
		}
		
		return $entity;
	}

	public static function getPrivateId($publicId)
	{
		$className = get_called_class();
		return $className::scope($publicId)->pluck('id');
	}

	public function getNmae()
	{
		return '';
	}

	public function scopeScope($query, $publicId = false, $accountId = false)
	{
		if (!$accountId) 
		{
			$accountId = Auth::user()->account_id;
		}
		
		$query->whereAccountId($accountId);

		if ($publicId)
		{
			if (is_array($publicId))
			{
				$query->whereIn('public_id', $publicId);
			}
			else
			{
				$query->wherePublicId($publicId);
			}
		}
		
		return $query;
	}
}