php 48 lines · 8 steps

Auto-generating unique slugs in Laravel

An Eloquent model that keeps a URL-friendly slug in sync with its title and guarantees it's unique.

Explained by highlit

Laravel Intermediate eloquent model-events slugs route-model-binding uniqueness

1<?php
2 
3namespace App\Models;
4 
5use Illuminate\Database\Eloquent\Model;
6use Illuminate\Support\Str;
7 
8class Article extends Model
9{
10    protected $fillable = ['title', 'body', 'slug'];
11 
12    protected static function booted(): void
13    {
14        static::saving(function (Article $article) {
15            if ($article->slug && ! $article->isDirty('title')) {
16                return;
17            }
18 
19            $article->slug = $article->generateUniqueSlug($article->title);
20        });
21    }
22 
23    protected function generateUniqueSlug(string $source): string
24    {
25        $base = Str::slug($source);
26        $slug = $base;
27        $suffix = 1;
28 
29        while ($this->slugExists($slug)) {
30            $slug = "{$base}-" . $suffix++;
31        }
32 
33        return $slug;
34    }
35 
36    protected function slugExists(string $slug): bool
37    {
38        return static::query()
39            ->where('slug', $slug)
40            ->when($this->exists, fn ($query) => $query->whereKeyNot($this->getKey()))
41            ->exists();
42    }
43 
44    public function getRouteKeyName(): string
45    {
46        return 'slug';
47    }
48}

01 / 01

STEP 01

Walkthrough

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Three takeaways

1Model lifecycle hooks let you enforce derived data at the exact moment a record is persisted.
2Suffixing and re-querying is a simple, reliable way to resolve collisions in a unique column.
3Overriding the route key lets you expose meaningful URLs instead of raw numeric IDs.

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