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Runtime Relation Mapping

HasDynamicRelations lets you register model relations at runtime.
It is ideal for reusable packages where consumers need project-specific relations without modifying package source code.

What Problem It Solves​

In package-first architecture, package models should not hardcode every relation needed by every host project.
This trait allows relation injection from the app layer.

Basic Setup​

use JobMetric\PackageCore\Models\HasDynamicRelations;

class Tag extends Model
{
    use HasDynamicRelations;
}

Register Dynamic Relations​

Tag::addDynamicRelation('posts', function ($model) {
    return $model
        ? $model->morphedByMany(Post::class, 'taggable')
        : (new Post)->morphedByMany(Tag::class, 'taggable');
});
Tag::addDynamicRelation('products', function ($model) {
    return $model
        ? $model->morphedByMany(Product::class, 'taggable')
        : (new Product)->morphedByMany(Tag::class, 'taggable');
});

Real project pattern (application layer):

Member::addDynamicRelation('orders', function ($model) {
    return $model
        ? $model->morphedByMany(Order::class, 'memberable')
        : (new Order)->morphedByMany(Member::class, 'memberable');
});

Usage​

$tags = Tag::with(['posts', 'products'])->get();

Best Practices​

  • Register dynamic relations in model boot() or a service provider
  • Use clear relation names (orders, products, etc.)
  • Keep relation closures idempotent and deterministic
  • Plan eager loading for heavy polymorphic relation graphs

Common Pitfalls​

  • Re-registering the same relation name unintentionally
  • Registering dynamic relations from multiple scattered places
  • Ignoring performance implications for polymorphic relations