marketplaces/docs/Category-Domain-Report.md

Category Domain Report

Scope

Sprint 4 added a complete Category Domain on top of the existing backend API contract. Backend endpoints and payload names were not changed.

Existing backend category fields remain isolated as DTO input:

• categoryID
• parentID
• name
• icon
• priority
• visible
• categoriesCount
• itemCount
• names[]

The UI now consumes category domain models rather than backend-shaped category responses.

Implemented Files

DTO

• src/app/core/categories/dto/category.dto.ts

Defines CategoryDto and CategoryNameDto for existing backend category payloads. Compatibility fields for current mock/API variants are accepted only at the DTO boundary.

Domain Model

• src/app/core/categories/models/category-domain.model.ts

Frontend category model exposes:

• id
• parentId
• title
• icon
• priority
• visible
• itemCount
• children[]
• translations

No backend category naming is required by category UI consumers.

Mapper

• src/app/core/categories/mappers/category.mapper.ts

Maps backend DTOs into domain categories, including:

• backend id normalization
• parent id normalization
• title fallback selection
• names[] to translations
• nested DTO flattening
• visible-category filtering
• priority sorting
• duplicate id de-duplication

Tree Utilities

• src/app/core/categories/utils/category-tree.utils.ts

Supports:

• flat list to tree
• unlimited nesting
• parent lookup
• children lookup
• breadcrumb generation
• leaf detection
• tree flattening for future lazy-loading compatibility

Repository Abstraction

• src/app/core/categories/repositories/category.repository.ts
• src/app/core/categories/repositories/api-category.repository.ts
• src/app/core/categories/category-repository.token.ts

CategoryRepository returns DTOs from the existing GET /category API. The injection token uses the existing runtime provider strategy and remains compatible with both mock and API modes. Mock mode continues to work through the existing mock-data interceptor.

Category Service

• src/app/core/categories/category.service.ts

Converts repository DTOs through the mapper and exposes domain methods:

• all categories
• category tree
• root categories
• category by id
• children
• parent
• breadcrumb
• leaf detection

Category Facade

• src/app/facades/platform/category.facade.ts

Exposes observable streams and state for:

• all categories
• category tree
• root categories
• category by id
• selected category
• breadcrumb
• children

Product Compatibility

• src/app/core/products/models/product-domain.model.ts
• src/app/core/products/providers/api-product-data.provider.ts

ProductFacade.getCategories() now resolves through CategoryService, so compatibility category access also returns the new category domain model.

UI Migration

Updated category-facing UI consumers:

• src/app/pages/home/home.component.ts
• src/app/pages/home/home.component.html
• src/app/pages/category/subcategories.component.ts
• src/app/pages/category/subcategories.component.html
• src/app/pages/category/category.component.ts

The home page and subcategory page now consume CategoryFacade and Category domain models. Category route item loading still uses the existing product facade for product lists, without changing product/payment/auth contracts.

Validation

Completed checks:

• DTOs are isolated under core/categories/dto.
• Category mapper exists and is the only category DTO-to-domain conversion point.
• Category UI uses CategoryFacade and category domain models.
• Category backend field names are contained to the category DTO/mapper boundary and compatibility internals.
• Components do not use HttpClient for category data.
• No authentication changes were made.
• No payment changes were made.
• No bootstrap contract changes were made.
• No backend API contract changes were made.
• Mock/API compatibility is preserved through the repository token and existing mock interceptor.

Build validation passed:

npm run build

Stop Point

Category Domain implementation is complete for Sprint 4. Stop here for approval before starting the next domain or any Builder/Backoffice work.