ocracy.registry#

Backend discovery, registration, and lazy loading.

An implemented backend is a subpackage of ocracy.backends that ships two things:

  • config.py defining a BACKEND_CONFIG dict (id, pip_install, capabilities, param_map, …), and

  • adapter.py defining an Adapter class whose read(image, **kwargs) returns an ocracy.base.OcrResult.

This registry scans for those at first use, loads each adapter lazily (so importing ocracy never imports heavy engine SDKs), and raises a friendly pip install error if a backend’s dependency is missing. Third parties can register their own backends at runtime via register_backend().

The design mirrors the sibling denote facade, adapted for OCR: the primary capability is "read" (image -> text+layout), with optional extra capabilities ("tables", "math", …) declared per backend.

Module Attributes

PRIMARY_CAPABILITY

The capability every general OCR backend provides.

Functions

clear_registry()

Clear all registered backends (useful for tests).

get_backend(backend_id)

Config + lazily-loaded adapter for a backend (raises on missing deps).

get_config(backend_id)

A backend's BACKEND_CONFIG without loading its adapter.

get_default_backend([capability, ...])

Pick a sensible default backend id for a capability.

list_backends([capability])

Sorted ids of implemented backends, optionally filtered by capability.

register_backend(backend_id, config[, adapter])

Register a backend at runtime (for third-party plugins).
ocracy.registry.PRIMARY_CAPABILITY = 'read'#

The capability every general OCR backend provides.

ocracy.registry.clear_registry()[source]#

Clear all registered backends (useful for tests).

Return type:

None

ocracy.registry.get_backend(backend_id)[source]#

Config + lazily-loaded adapter for a backend (raises on missing deps).

Return type:

dict

ocracy.registry.get_config(backend_id)[source]#

A backend’s BACKEND_CONFIG without loading its adapter.

Return type:

dict

ocracy.registry.get_default_backend(capability='read', *, require_available=True)[source]#

Pick a sensible default backend id for a capability.

Strategy (OCR-tuned): prefer a backend explicitly flagged default_for the capability and whose dependency is importable; then any importable backend for the capability; then — if require_available is False or nothing is installed — the first registered candidate (using it will raise a helpful install error).

Return type:

str

ocracy.registry.list_backends(capability=None)[source]#

Sorted ids of implemented backends, optionally filtered by capability.

A backend matches capability if it appears in the backend’s capabilities list (the primary "read" is implied for all).

Return type:

List[str]

ocracy.registry.register_backend(backend_id, config, adapter=None)[source]#

Register a backend at runtime (for third-party plugins).

Parameters:

  • backend_id (str) – Unique identifier.

  • config (dict) – BACKEND_CONFIG-shaped dict (needs at least name).

  • adapter (Any) – Optional pre-instantiated adapter; else loaded lazily from config['module_path'] when first used.

Return type:

None