Introduction to Nginx Reverse Proxy: Easily Achieve Frontend-Backend Separation
In a web front-end and back-end separation architecture, Nginx reverse proxy can solve problems such as cross-origin issues, complex domain name management, and back-end exposure. The reverse proxy acts as an intermediary server, so users access the back-end real service by visiting Nginx, which is transparent to users. When front-end and back-end are separated, reverse proxy can unify domain names (users only need to remember one domain name), hide the back-end address (enhancing security), and distribute requests by path (e.g., `/` for the front-end and `/api` for the back-end). Nginx is simple to install (Ubuntu uses `apt install nginx`, CentOS uses `yum install nginx`). The core of configuration is the `location` block: the front-end static files use `root` and `index` to point to the front-end directory, while the back-end API uses `proxy_pass` to forward to the real address, with `proxy_set_header` to pass header information. In practice, place the front-end files in the Nginx directory. After the back-end service is started, use `location` to distinguish paths. Nginx intercepts requests and forwards them, allowing users to complete front-end and back-end interaction by accessing a single domain name. Reverse proxy also supports extended functions such as load balancing and caching, making it a key tool in front-end and back-end separation architectures.
Read More3 Minutes to Understand: Defining and Using Routes in Python Web Development
This article introduces the concept of "routing" in web development and its application under the Flask framework. Routing is analogous to a restaurant waiter, responsible for receiving user requests (such as accessing a URL) and matching the corresponding processing logic (such as returning a web page), serving as the core that connects user requests with backend logic. The article focuses on the key usages of routing in Flask: 1. **Basic Routing**: Defined using `@app.route('/path')`, corresponding to a view function returning a response, such as the homepage at the root path `/`. 2. **Dynamic Parameters**: Receive user input via `<parameter_name>` or `<type:parameter_name>` (e.g., `int:post_id`), with automatic type conversion. 3. **HTTP Methods**: Specify allowed request methods using `methods=['GET','POST']`, combined with the `request` object to determine the request type. 4. **Reverse Lookup**: Dynamically generate routing URLs using `url_for('function_name', parameters)` to avoid hardcoding. The core is to achieve request distribution, parameter processing, and page interaction through routing. Mastering these basics can support page jumps and data interaction in web applications.
Read MoreIntroduction to User Authentication: Implementing Simple Login and Permission Control with Flask Session
This article introduces implementing user authentication and permission control for web applications using the Flask framework and Session mechanism, suitable for beginners. It first clarifies the concepts of user authentication (verifying identity) and permission control (judging access rights), emphasizing that Session is used to store user status, and Flask's `session` object supports direct manipulation. For environment preparation, install Flask, create an application, and configure `secret_key` to encrypt sessions. To implement the login function: collect username and password through a form, verify them (simulating a user database), set `session['username']`, and redirect to the personal center upon successful login. For permission control, use the `@login_required` decorator to check the Session and protect pages requiring login (e.g., the personal center). Logout clears the user status by `session.pop('username')`. Core content includes: Session basics, login verification, permission decorators, and logout functionality. The article summarizes the learned knowledge points and expands on directions such as database connection, password encryption, and multi-role permissions. Flask Session provides a simple and secure solution that can be gradually used to build complex applications.
Read MoreFlask Form Handling: Complete Process from User Input to Data Display
This article introduces the complete process of implementing form handling using Flask and Flask-WTF, suitable for web development scenarios requiring user information collection. First, install the Flask and Flask-WTF extensions, then create form classes by inheriting the `FlaskForm` class, defining fields (e.g., username, password) and validation rules (required, length, email format, etc.). In Flask applications, view functions must handle GET (rendering the form) and POST (validating submitted data) requests. Use `form.validate_on_submit()` to check the request type and validate data. If validation fails, error messages are stored in `form.<field>.errors`, and templates display errors through loops. Templates must include `form.hidden_tag()` to enable CSRF protection and avoid form submission failures. Key details include: setting `SECRET_KEY` to ensure CSRF security, using redirects to prevent duplicate submissions, and encrypting stored data (e.g., passwords with bcrypt). The complete workflow is: user fills out form → frontend validation → backend validation → data processing → result display. Advanced features can extend to custom validators, multi-form handling, or file uploads. This article helps quickly master core skills of Flask form implementation from definition to data processing.
Read MoreJinja2 Template Engine: Dynamically Rendering Data in Web Pages with Flask (with Examples)
This article introduces the role of template engines in web development and the application of Jinja2 in Flask. Template engines solve the cumbersome problem of splicing backend data with frontend HTML, allowing developers to focus on separating data logic from page structure. Jinja2 is Flask's default template engine, with a concise syntax that supports variable substitution, conditional judgment, loops, filters, and other features. The basic process of using Jinja2 involves: first installing Flask, creating an application and defining routes, preparing backend data (such as user information and article lists), and rendering the template through render_template. Template files should be placed in the 'templates' folder, where data is embedded using {{ variables }}, conditional logic and loops are implemented with {% if %} and {% for %}, and filters are applied using the | operator to process data. Template inheritance, through base.html and child templates, promotes code reusability by reusing page structures. The core syntax of Jinja2 includes variable substitution, conditional judgment, loop traversal, and filters, while template inheritance further optimizes project structure. Mastering Jinja2 enables efficient implementation of dynamic page rendering and is a key tool for connecting data and interfaces in web development.
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