Metadata Editor

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Technical specifications ​

Architecture ​

The application follows a three-tier architecture:

  • Frontend: Built using Vue.js, providing a responsive and interactive user interface for metadata editing.
  • Backend (Metadata Editor): PHP / CodeIgniter — application logic, authentication, sessions, job queue orchestration, and requests to the FastAPI service.
  • FastAPI service: Implemented using FastAPI (Python) (Metadata Editor FastAPI), offering high-performance endpoints for reading, validating, and converting statistical data (SPSS, Stata, CSV), and for indicator timeseries import, queries, charts, and export.

A separate background worker (metadata-editor-worker service) optionally processes long-running tasks from the Metadata Editor job queue (publish to NADA, PDF generation, API-driven imports). The application runs without it; the worker is recommended for batch, heavy, and automated workflows. See Jobs and background workers.

Frontend (Vue.js) ​

  • Framework: Vue.js
  • Key Libraries:
    • Vuetify
    • Vuex (state management)
    • Axios (API communication)
    • Vue Router

Backend (PHP) ​

  • Framework: CodeIgniter
  • Responsibilities:
    • Routing and user session management
    • Authentication and role-based access control
    • Background job queue (job_queue table) and background worker CLI
    • Request dispatch to the FastAPI service for data operations
    • Logging and error handling

FastAPI service (Python) ​

  • Framework: FastAPI
  • Dependencies (include among others):
    • pandas: Data manipulation and structure transformation
    • pyreadstat: Import/export of statistical file formats (SPSS, Stata, SAS)
    • Indicator timeseries: CSV import, validation, paging, charts, and export
  • Note: The FastAPI service runs its own internal jobs for some operations (e.g. large indicator CSV import). That is separate from the Metadata Editor background worker.

Background worker (optional) ​

  • Service name: metadata-editor-worker
  • Command: php index.php cli/worker/run (PHP CLI)
  • Purpose: Process job queue entries (publish, PDF, API imports, metadata assessment)
  • Required? No — the Metadata Editor functions without it; recommended for batch, heavy processing, and API automation
  • Deployment: systemd (Linux), NSSM (Windows), or worker.sh for manual/development use
  • Documentation: Jobs and background workers

Deployment ​

  • Server requirements:
    • PHP 8.2+
    • Apache/Nginx or IIS
    • Python 3.11+ (FastAPI service)
    • MySQL 8.x or MariaDB 10.x+