Falsk web 数据传递--flash

小灰灰 2021-12-10 04:43 183阅读 0赞

# 消息闪现 #

好的应用和用户界面的重点是回馈。如果用户没有得到足够的反馈，他们可能最终会对您的应用产生不好的评价。Flask 提供了一个非常简单的方法来使用闪现系统向用户反馈信息。闪现系统使得在一个请求结束的时候记录一个信息，然后在且仅仅在下一个请求中访问这个数据。这通常配合一个布局模板实现。

from flask import Flask, flash, redirect, render_template, \
         request, url_for
    
    app = Flask(__name__)
    app.secret_key = 'some_secret'
    
    @app.route('/')
    def index():
        return render_template('index.html')
    
    @app.route('/login', methods=['GET', 'POST'])
    def login():
        error = None
        if request.method == 'POST':
            if request.form['username'] != 'admin' or \
                    request.form['password'] != 'secret':
                error = 'Invalid credentials'
            else:
                flash('You were successfully logged in')
                return redirect(url_for('index'))
        return render_template('login.html', error=error)
    
    if __name__ == "__main__":
        app.run()

layout.html

<!doctype html>
    <title>My Application</title>
    {% with messages = get_flashed_messages() %}
      {% if messages %}
        <ul class=flashes>
        {% for message in messages %}
          <li>{
       { message }}</li>
        {% endfor %}
        </ul>
      {% endif %}
    {% endwith %}
    {% block body %}{% endblock %}

index.html 模板:

{% extends "layout.html" %}
    {% block body %}
      <h1>Overview</h1>
      <p>Do you want to <a href="{
       { url_for('login') }}">log in?</a>
    {% endblock %}

{% extends "layout.html" %}
    {% block body %}
      <h1>Login</h1>
      {% if error %}
        <p class=error><strong>Error:</strong> {
       { error }}
      {% endif %}
      <form action="" method=post>
        <dl>
          <dt>Username:
          <dd><input type=text name=username value="{
       {
              request.form.username }}">
          <dt>Password:
          <dd><input type=password name=password>
        </dl>
        <p><input type=submit value=Login>
      </form>
    {% endblock %}

参照：[http://docs.jinkan.org/docs/flask/patterns/flashing.html][http_docs.jinkan.org_docs_flask_patterns_flashing.html]

[http_docs.jinkan.org_docs_flask_patterns_flashing.html]: http://docs.jinkan.org/docs/flask/patterns/flashing.html