datatable.directory/app/Models/Proposal.php

<?php

namespace App\Models;

use App\Models\Concerns\NotificationContext;
use App\Models\Concerns\Reportable;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Database\Eloquent\Model;

/**
 * Change proposal
 *
 * @property Row[]|Collection $addedRows
 * @property Row[]|Collection $removedRows
 */
class Proposal extends Model
{
    use Reportable;
    use NotificationContext;

    protected static function boot()
    {
        parent::boot();

        static::deleting(function(Proposal $self) {
            // update refcounts
            $self->addedRows()->decrement('refs');
            $self->removedRows()->decrement('refs');
        });
    }

    /** Added rows */
    public function addedRows()
    {
        return $this->belongsToMany(Row::class, 'proposal_add_row_pivot');
    }

    /** Removed rows */
    public function removedRows()
    {
        return $this->belongsToMany(Row::class, 'proposal_remove_row_pivot');
    }

    /** Authoring user */
    public function author()
    {
        return $this->belongsTo(User::class, 'author_id');
    }

    /** Target revision */
    public function revision()
    {
        return $this->belongsTo(Revision::class);
    }

    /** Target table (that this was submitted to) */
    public function table()
    {
        return $this->belongsTo(Table::class);
    }
}