SimpleDecision

An example full-stack application that follows a decision graph question-by-question.

Backend: Spring Boot (Java 17) with H2 database and JPA. Frontend: Vue 3 + Vite (Element Plus for styling).

Features

• Pet recommendation flow using 3–5 narrowing questions
• Questions and answers stored in a local H2 database
• Each question has related answers; each answer can point to the next question (or end)
• Frontend displays the current question and related answers; selecting an answer moves to the next question
• User’s chosen answers are persisted per-session in the database and can be viewed at any point

Running

1. Build frontend into backend resources

   • From frontend/: npm install then npm run build

2. Run backend

   • From backend/: mvn spring-boot:run
   • App will be available at http://localhost:8080

The frontend is served by Spring Boot (prebuilt into backend/src/main/resources/public).

Configuring the backend base address (frontend)

The frontend uses a configurable base URL for API requests.

• Default: http://localhost:8080/
• Override: set VITE_API_BASE in a Vite env file (for example: frontend/.env, frontend/.env.development, or frontend/.env.production).

Example frontend/.env:

VITE_API_BASE=http://api.example.com/

The app’s API paths (like api/graph/...) are automatically resolved against this base URL.

H2 console is available at: http://localhost:8080/h2-console

• JDBC URL: jdbc:h2:file:./data/decisiondb (as configured)
• Username: sa
• Password: empty

API documentation (OpenAPI / Swagger)

• Swagger UI: http://localhost:8080/swagger-ui.html (or http://localhost:8080/swagger-ui/index.html)
• OpenAPI JSON: http://localhost:8080/v3/api-docs
• OpenAPI YAML: http://localhost:8080/v3/api-docs.yaml

API (used by the frontend)

• GET /api/graph/processes → list of available processes to start (each item: { id, name })
• POST /api/graph/process/{processId}/start → start the selected process; returns its starting questions as an array
• GET /api/graph/current → array of current active questions with answers; returns null if multiple processes exist and none selected; auto-starts if only one process exists
• POST /api/graph/answer/{answerId} → select an answer; returns updated array of current questions (empty array means process finished)
• GET /api/graph/history → list of selected answers for the current session (persisted)
• POST /api/graph/reset → reset current session (clears persisted answers for this session)

Admin CRUD API

Endpoints to manage all models. All under /api/admin:

• Questions

  • GET /questions → list questions
  • GET /questions/{id} → get question
  • POST /questions → create question { text, root }
  • PUT /questions/{id} → update question { text, root }
  • DELETE /questions/{id} → delete question (cascades answers)

• Answers

  • GET /answers → list answers
  • GET /answers/{id} → get answer
  • POST /answers → create { text, questionId, nextQuestionId? }
  • PUT /answers/{id} → update { text, questionId, nextQuestionId? }
  • DELETE /answers/{id} → delete answer

• Processes

  • GET /processes → list processes
  • GET /processes/{id} → get process
  • POST /processes → create { name, startingQuestionIds?[] }
  • PUT /processes/{id} → update { name, startingQuestionIds?[] }
  • DELETE /processes/{id} → delete process

• Answer Records

  • GET /answer-records → list answer records
  • GET /answer-records/{id} → get answer record
  • DELETE /answer-records/{id} → delete answer record