Flask and Frontend Interaction: AJAX Requests and JSON Responses

This article introduces the method of implementing front-end and back-end data interaction in Flask using AJAX and JSON. In a front-end and back-end separated architecture, the front-end is responsible for interface interaction, while the back-end handles business logic. AJAX enables asynchronous requests, and JSON serves as the data exchange format. The core process is: front-end initiates an asynchronous request → back-end processes and returns JSON → front-end parses and renders the data. Practical example: Create `app.py` in Flask, where the `/` route renders the front-end page, and the `/api/get_data` route returns simulated JSON data (including status, message, and a list). The front-end uses `fetch` to asynchronously request `/api/get_data`, and updates the page after obtaining the data. Key knowledge points include: using `jsonify` on the back-end to return JSON, using `async/await` on the front-end to simplify asynchronous code, supporting GET/POST requests and data transfer (e.g., `request.get_json()` to receive front-end data). The core steps are clear, and it can be extended to scenarios such as form submission and database interaction.