Developing add-ons¶

Add-ons are a way to customize localization workflow in Weblate.

class weblate.addons.base.BaseAddon(storage)¶

Base class for Weblate add-ons.

classmethod can_install(*, component=None, category=None, project=None) → bool¶: Check whether add-on is compatible with given component.

change_event(change, activity_log_id: int | None = None) → dict | None¶: Event handler for change event.

check_change_action(change) → bool¶: Early filtering of Change actions before triggering change_event callback.

component_update(component, activity_log_id: int | None = None) → dict | None¶: Event handler for component update.

configure(configuration) → None¶: Save configuration.

daily(component=None, category=None, project=None, activity_log_id: int | None = None) → dict | None¶

Scope-aware daily entry point.

Override this for project-level logic, or override daily_component() for per-component logic.

daily_component(component, activity_log_id: int | None = None) → dict | None¶: Per-component daily processing. Override this for component-level logic.

classmethod get_add_form(user, *, component=None, category=None, project=None, **kwargs)¶: Return configuration form for adding new add-on.

get_settings_form(user, **kwargs)¶: Return configuration form for this add-on.

manual(component=None, category=None, project=None, activity_log_id: int | None = None) → dict | None¶

Scope-aware manual entry point.

By default this mirrors the daily handler and lets add-ons opt in explicitly by subscribing to the manual event.

manual_component(component, activity_log_id: int | None = None) → dict | None¶: Per-component manual processing.

post_add(translation, activity_log_id: int | None = None) → dict | None¶: Event handler after new translation is added.

post_commit(component, store_hash: bool, activity_log_id: int | None = None) → dict | None¶: Event handler after changes are committed to the repository.

post_install(component, store_hash: bool, activity_log_id: int | None = None) → dict | None¶: Event handler after add-on is installed.

post_push(component, activity_log_id: int | None = None) → dict | None¶: Event handler after repository is pushed upstream.

post_remove(translation, activity_log_id: int | None = None) → dict | None¶: Event handler after a translation is removed.

post_update(component, previous_head: str, skip_push: bool, activity_log_id: int | None = None) → dict | None¶

Event handler after repository is updated from upstream.

Parameters:

previous_head (str) – HEAD of the repository prior to update, can be blank on initial clone.
skip_push (bool) – Whether the add-on operation should skip pushing changes upstream. Usually you can pass this to underlying methods as commit_and_push or commit_pending.

pre_commit(translation, author: str, store_hash: bool, activity_log_id: int | None = None) → dict | None¶: Event handler before changes are committed to the repository.

pre_push(component, activity_log_id: int | None = None) → dict | None¶: Event handler before repository is pushed upstream.

pre_update(component, activity_log_id: int | None = None) → dict | None¶: Event handler before repository is updated from upstream.

resolve_components(*, component=None, category=None, project=None)¶: Resolve scope to components iterator.

save_state() → None¶: Save add-on state information.

unit_pre_create(unit, activity_log_id: int | None = None) → dict | None¶: Event handler before new unit is created.

update_component_state(component, updater: Callable[[dict[str, object]], None]) → None¶: Atomically merge component-scoped add-on state into the shared JSON field.

user()¶: Weblate user used to track changes by this add-on.

Add-on hooks receive ORM objects from the weblate.*.models modules, including Addon, Component, Translation, Category, Project, Unit, Change, and User. Add-on configuration forms should subclass weblate.addons.forms.BaseAddonForm.

Here is an example add-on:

# Copyright © Michal Čihař <michal@weblate.org>
#
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations

from typing import TYPE_CHECKING, ClassVar

from django.utils.translation import gettext_lazy

from weblate.addons.base import BaseAddon
from weblate.addons.events import AddonEvent

if TYPE_CHECKING:
    from weblate.addons.base import CompatDict


class ExampleAddon(BaseAddon):
    # Filter for compatible components, every key is
    # matched against property of component
    compat: ClassVar[CompatDict] = {
        "file_format": {"po", "po-mono"},
    }
    # List of events add-on should receive
    events: ClassVar[set[AddonEvent]] = {
        AddonEvent.EVENT_PRE_COMMIT,
    }
    # Add-on unique identifier
    name = "weblate.example.example"
    # Verbose name shown in the user interface
    verbose = gettext_lazy("Example add-on")
    # Detailed add-on description
    description = gettext_lazy("This add-on does nothing it is just an example.")

    # Callback to implement custom behavior
    def pre_commit(
        self,
        translation,
        author: str,
        store_hash: bool,
        activity_log_id: int | None = None,
    ) -> None:
        return

Typing add-on configuration¶

Add-on configuration is stored in the Addon.configuration JSON field, so the model keeps the persisted data as raw JSON. Add-on implementations can type their own configuration by parameterizing BaseAddon and BaseAddonForm.

Use two TypedDict classes when the stored JSON can differ from the runtime shape: a permissive, usually total=False, stored configuration for legacy or missing values, and a total runtime configuration returned by normalize_configuration(). Runtime add-on code should read self.configuration or self.get_configuration() so it sees normalized defaults instead of raw persisted JSON.

For simple add-ons where the stored and runtime shapes are identical, define a single TypedDict and use it for both BaseAddon type parameters. Keep the form’s serialize_form() return type aligned with the stored configuration type.