Link Collector
Prevent duplicate page links

How It Works

The LinkCollector scans your page content before Twig/Markdown processing and collects all internal link slugs. These slugs are then available to filter out from your page listings.

Raw Content:
  "Check out [our Alps tours](/alps/hiking) and..."

  ↓ LinkCollector scans content
  → Finds: "/alps/hiking"
  → Registers slug in collector

  ↓ Twig executes (pages_list, custom functions)
  → Can now exclude "alps/hiking" from results

  ↓ Final output
  → No duplicate links

Supported Link Formats

The collector detects internal links in these formats:

Not collected:

• External links (https://example.com)
• Relative links (relative-page without leading /)
• Anchor-only links (#section)

Usage with pages_list

The simplest way to use this feature is with the excludeAlreadyLinked parameter:

{{ pages_list('children', 6, excludeAlreadyLinked: true) }}

This automatically excludes any pages that are already linked in your content.

Full Example

{# Your page content contains links like [See our hiking tours](/hiking) #}
<h2>Related Products</h2>
{{ pages_list('taxonomy:outdoor', 4, excludeAlreadyLinked: true) }}
{# hiking page won't appear here since it's already linked above #}

Usage with pages() Function

For more control, use the exclude_linked() function with pages():

{% set allPages = pages(host, 'taxonomy:travel') %}
{% set uniquePages = exclude_linked(allPages) %}
<ul>
{% for page in uniquePages %}
  <li><a href="{{ pw_path(page) }}">{{ page.title }}</a></li>
{% endfor %}
</ul>

Available Twig Functions

Checking Individual Slugs

{% for page in pages(host, 'related') %}
  {% if not is_slug_linked(page.slug) %}
    <a href="{{ pw_path(page) }}">{{ page.title }}</a>
  {% endif %}
{% endfor %}

Debugging Collected Links

{# See what links were collected from your content #}
{{ dump(linked_slugs()) }}
{# Output: ['alps/hiking', 'beach-trips', 'contact'] #}

Usage in Custom Twig Functions (PHP)

If you create custom Twig functions that return page lists, inject the LinkCollectorService:

use Pushword\Core\Service\LinkCollectorService;

final class MyExtension
{
    public function __construct(
        private readonly LinkCollectorService $linkCollector,
    ) {
    }

    #[AsTwigFunction('my_product_list', isSafe: ['html'])]
    public function renderProductList(): string
    {
        $pages = $this->getProductPages();

        // Exclude pages already linked in content
        $pages = $this->linkCollector->excludeRegistered($pages);

        // Render...
    }
}

LinkCollectorService API

// Register a slug manually
$linkCollector->registerSlug('my-page');

// Register from a Page entity
$linkCollector->register($page);

// Check if a slug is registered
$linkCollector->isSlugRegistered('my-page'); // true/false

// Filter an array of pages
$uniquePages = $linkCollector->excludeRegistered($pages);

// Get all registered slugs
$slugs = $linkCollector->getRegisteredSlugs(); // ['slug' => true, ...]

Real-World Examples

Travel Agency Site

{# Page content mentions specific destinations #}
Discover our [Paris tours](/destinations/paris) and
[Rome adventures](/destinations/rome).

{# Sidebar shows other destinations, excluding mentioned ones #}
<aside>
  <h3>Other Destinations</h3>
  {{ pages_list('taxonomy:destination', 5, excludeAlreadyLinked: true) }}
</aside>

Blog with Related Posts

{# Article references other posts inline #}
As mentioned in [Getting Started](/blog/getting-started)...

{# Related posts section excludes referenced articles #}
<section class="related">
  <h2>You might also like</h2>
  {{ pages_list('sisters', 3, excludeAlreadyLinked: true) }}
</section>

E-commerce Product Page

{# Product description links to related products #}
This pairs well with our [Premium Case](/accessories/premium-case).

{# Recommended products excludes already-mentioned items #}
<div class="recommendations">
  {% set recommendations = exclude_linked(pages(host, 'taxonomy:accessory')) %}
  {% for product in recommendations|slice(0, 4) %}
    {% include '/component/product_card.html.twig' with {page: product} %}
  {% endfor %}
</div>

Performance Notes

• The LinkCollector filter runs once per page render, before Twig processing
• Link detection uses optimized regex patterns with minimal overhead
• The collector is automatically reset on each HTTP request
• No database queries are made for link collection

Backward Compatibility

This feature is enabled by default but has zero impact on existing sites:

• The filter always runs but only collects links passively
• No content is modified
• Filtering only happens when you explicitly use excludeAlreadyLinked: true or exclude_linked()