Layer 5: Blade Fragment Caching (@atomicCache)

Cache expensive HTML blocks, navigation bars, and widgets directly inside your Blade views.

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5.1 Usage & Tagging

Wrap HTML blocks using @atomicCache and close with @endAtomicCache:

{{-- Caches rendered HTML for 3600 seconds, tagged with 'categories' and 'sub_categories' --}}
@atomicCache('sidebar_categories', 3600, ['categories', 'sub_categories'])
    <div class="sidebar">
        @foreach(\App\Models\Category::with('subcategories')->get() as $category)
            <h3>{{ $category->name }}</h3>
            @foreach($category->subcategories as $sub)
                <p>{{ $sub->title }}</p>
            @endforeach
        @endforeach
    </div>
@endAtomicCache

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5.2 Critical Rules & What Breaks Blade Caching

Never Cache Forms or CSRF Tokens

CSRF tokens are unique to each user session. If you cache a form containing @csrf, the first user's CSRF token is stored. When subsequent users submit the form, they will receive a 419 Page Expired error!

Never Cache User-Specific Data Without User Scoping

If you cache a block containing @atomicCache('user_header') with the user's name or cart count, User A's personal information will be cached and shown to User B (a major data leak).

Solution: Append the user ID to the key:

@atomicCache('user_header_' . auth()->id(), 3600)

• Multi-table dependencies: If your cached Blade fragment renders data from multiple models/tables (such as categories and subcategories), specify all relevant tags: @atomicCache('sidebar', 3600, ['categories', 'sub_categories']). If you only pass 'categories', updates to subcategories will not invalidate the cached HTML.
• Never cache session flash messages or @error directives: session('status') or @error('email') cached inside a fragment will either never display or remain permanently visible to all subsequent visitors.
• Unclosed @atomicCache blocks: Omitting @endAtomicCache leaves an active PHP output buffer open, which can break page rendering.