Lifecycle Hooks

Lifecycle hooks let you add domain behavior around the generated CRUD routes without rewriting the whole endpoint.

Create and Update Flow

For POST, PUT, and PATCH, Ronin calls:

1. validate_data(data)
2. self.state.validated_data = data
3. obj.update_from_dict(data.model_dump(exclude_unset=True))
4. before_save(obj)
5. perform_create(obj) or perform_update(obj)
6. perform_save(obj)
7. after_save(obj)
8. serialize with read_schema

Available Hooks

Hook	Purpose
validate_data(data)	Normalize or reject request data before it is applied.
before_save(obj)	Run checks or enrich the object before saving.
perform_save(obj)	Central save operation used by create and update.
perform_create(obj)	Customize create persistence.
perform_update(obj)	Customize update persistence.
after_save(obj)	Run side effects after persistence.
perform_destroy(obj)	Customize delete behavior.

Validation Example

from fastapi import HTTPException


@viewset(router)
class CompanyViewSet(ModelViewSet[Company]):
    model = Company
    read_schema = CompanySchema
    create_schema = CompanyCreateSchema

    async def validate_data(self, data: CompanyCreateSchema):
        if data.name.strip() == '':
            raise HTTPException(status_code=400, detail='Company name is required')
        return data

Save Hooks

@viewset(router)
class TaskViewSet(ModelViewSet[Task]):
    model = Task
    read_schema = TaskSchema
    create_schema = TaskCreateSchema

    async def before_save(self, obj: Task):
        await obj.fetch_related('project')
        if not obj.project.active:
            raise HTTPException(status_code=400, detail='Project is not active')

    async def after_save(self, obj: Task):
        await cache.delete(f'project:{obj.project_id}:stats')

Soft Delete

@viewset(router)
class ProjectViewSet(ModelViewSet[Project]):
    model = Project
    read_schema = ProjectSchema
    create_schema = ProjectCreateSchema

    def get_queryset(self):
        return Project.filter(active=True)

    async def perform_destroy(self, obj: Project):
        obj.active = False
        await obj.save()

Access Validated Data

During create and update, Ronin stores the request model on state:

async def before_save(self, obj: Company):
    data = self.state.validated_data
    if data.status == 'inactive':
        obj.deactivated_by = self.user['id']

Guidance

• Use validate_data() for request-level checks.
• Use before_save() for object-level checks before persistence.
• Use after_save() for cache invalidation and other side effects.
• Use perform_destroy() for soft delete.
• Keep hooks focused; move larger domain workflows into service functions.