Laravel

Quick Reference

Topic	File
N+1 queries, eager loading, accessors, observers	eloquent.md
Validation, middleware order, dependency injection	controllers.md
Job serialization, retries, failed jobs	queues.md
Guards, policies, gates, Sanctum tokens	auth.md
XSS escaping, components, slots	blade.md
Commands, scheduling, tinker	artisan.md

Critical Rules

• Eager load relationships — with('posts') not lazy ->posts in loop (N+1)
• preventLazyLoading() in dev AppServiceProvider — crashes on N+1, catches early
• env() only in config files — returns null after config:cache
• $fillable whitelist fields — $guarded = [] allows mass assignment attacks
• find() returns null — use findOrFail() to avoid null checks
• Job properties serialize models as ID — re-fetched on process, may be stale/deleted
• route:cache requires controller routes — closures break cached routes
• DB::transaction() doesn't catch exit/timeout — only exceptions roll back
• RefreshDatabase uses transactions — faster than DatabaseMigrations
• {!! $html !!} skips escaping — XSS vector, use {{ }} by default
• Middleware order matters — earlier middleware wraps later execution
• required validation passes empty string — use required|filled for content
• firstOrCreate persists immediately — firstOrNew returns unsaved model
• Route model binding uses id — override getRouteKeyName() for slug