{"id":"observer-designed-for-pattern-composition","text":"Observer's design includes features that facilitate pattern composition: Template Method can enforce self-consistency before notification (supporting reliable state for composed patterns that depend on Observer updates), while ChangeManager demonstrates Observer composing with Mediator to handle complex multi-subject update scenarios by centralizing distributed notifications — suggesting Observer accommodates integration with other patterns.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["observer-consistency-via-template-method","changemanager-mediator-observer-composition"],"outlist":[],"label":"Template Method integration (reliability) + ChangeManager (composition exemplar) show Observer is composition-ready by design"}],"dependents":["observer-principled-composition-architecture","observer-principled-composition-reliably-applicable"],"metadata":{"source_type":"derived","review_result":"pass","repair_action":"softened"},"created_at":"2026-06-17T23:12:23+00:00","updated_at":"2026-06-18T06:15:08+00:00","reviewed_at":"2026-06-18T06:15:08+00:00","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"observer-designed-for-pattern-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["observer-consistency-via-template-method","changemanager-mediator-observer-composition"],"label":"Template Method integration (reliability) + ChangeManager (composition exemplar) show Observer is composition-ready by design"},{"node":"observer-consistency-via-template-method","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-observer-notify-after-consistent-state","gof-template-method-hollywood-principle"],"label":"Observer's consistency requirement and Template Method's inverted control connect as enforcement mechanism to correctness constraint"},{"node":"gof-observer-notify-after-consistent-state","truth_value":"IN","reason":"premise"},{"node":"gof-template-method-hollywood-principle","truth_value":"IN","reason":"premise"},{"node":"changemanager-mediator-observer-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-changemanager-mediator-singleton","observer-mediator-distribution-centralization-tradeoff"],"label":"ChangeManager is a concrete case where the abstract Observer-Mediator tradeoff is resolved by composition rather than selection — depth-2 from base + depth-1"},{"node":"gof-changemanager-mediator-singleton","truth_value":"IN","reason":"premise"},{"node":"observer-mediator-distribution-centralization-tradeoff","truth_value":"IN","reason":"SL justification valid","antecedents":["mediator-centralizes-observer-distributes","observers-more-reusable-than-mediators","gof-observer-unexpected-updates-liability","gof-mediator-centralizes-control-tradeoff"],"label":"Two base beliefs on the relationship + one liability each combine into a unified architectural tradeoff"},{"node":"mediator-centralizes-observer-distributes","truth_value":"IN","reason":"premise"},{"node":"observers-more-reusable-than-mediators","truth_value":"IN","reason":"premise"},{"node":"gof-observer-unexpected-updates-liability","truth_value":"IN","reason":"premise"},{"node":"gof-mediator-centralizes-control-tradeoff","truth_value":"IN","reason":"premise"}]}}