031-flash-card/docs/uc-001/sd.md

Sequence Diagrams: Study Flash Cards

Metadata

Key	Value
ID	SD-001
CrossReference	OC-001, DCD-001, DICT-001

Version History

Date	Status	Author	Reviewer	Change	Commit
2026-10-14	Accepted	Jens Tirsvad Nielsen	AI as stand-in for S01	Initial version	c3fbcbc

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Sequence: startStudySession

Realizes: startStudySession in OC-001

Diagram

@startuml
participant "main : app" as M
participant ":CsvVocabularyRepository" as VR
participant ":CsvProgressRepository" as PR
participant ":StudySession" as S
participant ":Deck" as D
participant ":SpeechPort" as SP
M -> PR : load()
PR --> M : deck | None
alt deck is None
  M -> VR : load()
  VR --> M : vocabulary
  create D
  M -> D : from_vocabulary(vocabulary)
  D --> M : deck
end
create S
M -> S : create(deck, progress, speech, choose)
M -> S : next_card()
activate S
opt deck is not empty
  S -> D : draw(choose, exclude)
  D --> S : card
  S -> SP : speak(card.front, front_code)
end
S --> M : CardDto | None
deactivate S
@enduml

Pattern Annotations

Pattern (GRASP / GoF)	Applied to	Rationale
Creator	app.main creates StudySession	It holds the adapters the session needs
Information Expert	Deck draws and removes its own cards	It owns the list of cards
Null Object	NullSpeech as SpeechPort	The session never tests for speech

Postcondition Coverage

Postcondition (from contract)	Satisfied by message
A StudySession instance was created	create(deck, progress, speech, choose)
A Deck was created from the progress file or a copy of the Vocabulary	PR.load(), alt fragment, from_vocabulary
current_card set and a CardDto returned, or None	next_card() with the opt fragment

Responsibility Check

The session coordinates, the deck holds the cards, the repositories hold the file format; no object receives all messages.

Sequence: markKnown

Realizes: markKnown in OC-001

Diagram

@startuml
participant ":FlashCardView" as V
participant ":FlashCardViewModel" as VM
participant ":StudySession" as S
participant ":Deck" as D
participant ":CsvProgressRepository" as PR
V -> VM : is_known()
activate VM
VM -> S : mark_known()
activate S
opt current_card is not None
  S -> D : remove(card)
  S -> PR : save(deck)
end
deactivate S
VM -> S : next_card()
S --> VM : CardDto | None
VM --> V : side, language name, text
deactivate VM
@enduml

Pattern Annotations

Pattern (GRASP / GoF)	Applied to	Rationale
MVVM	FlashCardView, FlashCardViewModel	The view raises the event and shows the result; the rule is behind the view model
Repository	CsvProgressRepository	The session stores the deck through a port

Postcondition Coverage

Postcondition (from contract)	Satisfied by message
The card was removed from the Deck	remove(card)
The Deck was stored	save(deck)
current_card was set to None	mark_known() ends with no current card; next_card() then draws the next

Responsibility Check

The view model only sequences two session calls and maps the result for the view.

Sequence: markUnknown

Realizes: markUnknown in OC-001

Diagram

@startuml
participant ":FlashCardView" as V
participant ":FlashCardViewModel" as VM
participant ":StudySession" as S
participant ":Deck" as D
participant ":SpeechPort" as SP
V -> VM : next_card()
VM -> S : next_card()
activate S
opt deck is not empty
  S -> D : draw(choose, exclude=current)
  D --> S : card
  S -> SP : speak(card.front, front_code)
end
S --> VM : CardDto | None
deactivate S
VM --> V : side, language name, text
@enduml

Pattern Annotations

Pattern (GRASP / GoF)	Applied to	Rationale
Information Expert	Deck.draw	The deck knows its cards

Postcondition Coverage

Postcondition (from contract)	Satisfied by message
A different card was chosen when two or more exist	draw(choose, exclude=current)
Deck and file unchanged	no remove or save message
The Malay word was passed to the SpeechPort	speak(card.front, front_code)

Responsibility Check

Same as markKnown; the session is the only object that speaks and draws.

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