Module filter 

Document subscription filtering Document subscription filtering

This module provides primitives to express and evaluate subscription filters for document state transitions. The main entry point is DriveDocumentQueryFilter, which holds a contract reference, a document type name, and action-specific match clauses (DocumentActionMatchClauses).

Filtering in brief:

• Create: evaluates new_document_clauses on the transition’s data payload.
• Replace: evaluates original_document_clauses on the original document and new_document_clauses on the replacement data.
• Delete: evaluates original_document_clauses on the original document.
• Transfer: evaluates original_document_clauses and a new owner_clause against the recipient_owner_id.
• UpdatePrice: evaluates original_document_clauses and a price_clause against the new price in the transition.
• Purchase: evaluates original_document_clauses and an owner_clause against the batch owner (purchaser) ID.

Usage:

• First check: call matches_document_transition() per transition to evaluate applicable constraints before fetching the original document. Decide whether to fetch the original document (returns Pass/Fail/NeedsOriginal).
• Second check: only if the first check returned NeedsOriginal, fetch the original Document and call matches_original_document() to evaluate original-dependent clauses.

Validation:

• validate() performs structural checks: confirms the document type exists for the contract, enforces action-specific composition rules (e.g., at least one non-empty clause where required), and validates operator/value compatibility for scalar clauses like owner_clause and price_clause.

Structs

DriveDocumentQueryFilter

Filter used to match document transitions for subscriptions.

Enums

DocumentActionMatchClauses

Action-specific filter clauses for matching document transitions.

TransitionCheckResult

Result of evaluating constraints for a transition before potentially fetching the original document.