Stop: Architecture Reference#

Purpose#

The Stop action provides a clean exit point from the rule execution loop. It is designed to be minimal and leverage standard Frappe exception handling for its Error mode.

Class Structure#

StopHandler(ActionHandler)#

• Location: flexirule/ruleflow/core/action_handlers/simple_actions.py
• Responsibility: Terminates the execution flow.
• Methods:
  • execute(action, context, engine): Implementation of the terminal logic.

Execution Pipeline#

1. Operation Check: mode = (getattr(action, "operation", None) or "Success").strip()
2. Success Path: Returns (None, None), which signals the RuleEngine to terminate the loop.
3. Error Path:
   • Retrieves value_template.
   • Builds a template context containing doc, vars, and frappe.
   • Calls frappe.render_template.
   • Appends a source_link HTML snippet to the message for administrative traceability.
   • Calls frappe.throw(message, title=_("Rule Error")).

Context Mutation Model#

The Stop action is Read-Only. It never modifies the context. However, in Error mode, it causes a system-wide mutation by rolling back the current database transaction.

Dependencies#

• frappe.throw: Used to raise ValidationError and stop the request.
• frappe.render_template: Used for generating dynamic error messages.

Source Files#

• Handler: flexirule/ruleflow/core/action_handlers/simple_actions.py
• Contract: flexirule/ruleflow/core/contracts.py

Related Topics#

• Action Documentation
• Execution Semantics