leezard/app/Models/SmsTemplate.php

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class SmsTemplate extends Model
{
    use HasFactory;

    protected $fillable = [
        'name',
        'content',
        'created_by'
    ];

    protected $casts = [
        'created_at' => 'datetime',
        'updated_at' => 'datetime',
    ];

    public function creator()
    {
        return $this->belongsTo(User::class, 'created_by');
    }

    public function getCharacterCountAttribute()
    {
        return strlen($this->content);
    }
}