Service locator

Features register replaceable service classes on app.splent_services. Routes look up the current implementation at request time — after all features (including refiners) have loaded.

Table of contents

• Base feature registers
• Routes consume via proxy
• Refiner overrides
• See also

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Base feature registers

# splent_feature_notes/__init__.py
from splent_framework.services.service_locator import register_service
from .services import NotesService

def init_feature(app):
    register_service(app, "NotesService", NotesService)

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Routes consume via proxy

# splent_feature_notes/routes.py
from splent_framework.services.service_locator import service_proxy

notes_service = service_proxy("NotesService")

@notes_bp.route("/notes/", methods=["GET"])
@login_required
def index():
    notes = notes_service.get_by_user(current_user.id)
    ...

service_proxy resolves the registered class at request time. Same pattern Flask uses with current_app.

Never import the service class directly in routes (from .services import NotesService). Direct imports create the instance at module load, before refiners have registered overrides. Use service_proxy() instead.

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Refiner overrides

# splent_feature_notes_tags/__init__.py
from splent_framework.refinement import refine_service
from .services import NotesServiceWithTags

def init_feature(app):
    refine_service(app, "NotesService", NotesServiceWithTags)

refine_service builds a merged class inheriting from both NotesServiceWithTags and NotesService, so super() works correctly. Routes using service_proxy("NotesService") automatically get the merged class.

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See also

• Services — the service layer architecture
• Refinement — the full override mechanism