OptimisticAction

OptimisticAction is a button preset for optimistic UI flows where the UI updates immediately, then either commits or rolls back based on the server response.

Import

from faststrap.presets import OptimisticAction

Basic Usage

OptimisticAction(
    "Archive",
    endpoint="/items/42/archive",
    target="#item-42",
    action_id="archive-42",
    payload={"item_id": 42},
    variant="warning",
)

Event Contract

OptimisticAction dispatches bubbling CustomEvents from the button:

• faststrap:optimistic:apply before request starts
• faststrap:optimistic:commit after successful response
• faststrap:optimistic:rollback when request fails

Event detail includes:

• actionId
• endpoint
• method
• target
• payload
• reason

Server Contract Recommendation

Use idempotent endpoints and return consistent error status codes for failed writes. Client listeners should:

1. Apply temporary UI state on apply
2. Finalize UI state on commit
3. Restore previous UI state on rollback

Notes

• Supported methods: get, post, put, patch, delete
• Unsupported methods raise ValueError
• Designed as an interaction preset; no Faststrap core API changes required