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  • Flask Blueprint

    Blueprint简介

    Blueprint它是Flask项目的一种组件式开发,可以在一个应用内或跨越 多个项目共用蓝图。使用蓝图可以极大地简化大型应用的开发难度,也为Flask扩展 提供了一种在应用中注册服务的集中式机制。 模块化管理程序路由是它的特色,它使程序结构清晰、简单易懂。但是一个Blueprint并不是一个完整的应用,它不能独立于应用运行,而必须要注册到某一个应用中。

    由于只是演示蓝图的基本用法,所以这里以展示用户表,登陆认证,编辑用户,删除用户,新增用户来模拟多个模块作为演示。

    环境搭建:

    1、创建项目damo_2,在该项目下创建static(存放图片,css样式,js脚本等)、templates(HTML文件)两个目录。

    2、新建一个settings.py的配置文件,配置文件中存放用户表

    USER_INFO = [{'aaa':'111'},{'bbb':'222'},{'ccc':'333'}]  # 模拟数据库中的用户表

    一、函数的方式(FBV):

    1、展示用户表

    1.1创建show.py

    from flask import Blueprint,render_template
    from settings import USER_INFO
    
    show_app = Blueprint('show_app',__name__)
    @show_app.route('/show_page')
    def show_page():
        return render_template('show_page.html',user_info=USER_INFO)

     1.2在templates目录下创建show_page.html

    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <h3 style="margin-left: 320px">用户详情表</h3>
    <form action="">
        <table border="1px">
            <thead>
            <tr>
                <th style=" 150px;">序号</th>
                <th style=" 150px;">用户</th>
                <th style=" 150px;">密码</th>
                <th style=" 150px;">操作</th>
            </tr>
            </thead>
            <tbody>
            {% for user_dict in user_info %}
    
                <tr>
                    <td style="text-align: center">{{ loop.index0 }}</td>
                    {% for user in user_dict %}
                        <td style="text-align: center">{{ user }}</td>
                        <td style="text-align: center">{{ user_dict.get(user) }}</td>
                    {% endfor %}
                    <td style="text-align: center">
                        <a href="/edit_user?id={{ loop.index0 }}">编辑</a>
                        |
                        <a href="/del_user?id={{ loop.index0 }}">删除</a>
                    </td>
                </tr>
            {% endfor %}
            </tbody>
        </table>
        <br>
        <a href="/add_user">新增</a>
    </form>
    </body>
    </html>
    show_page

    2、新增用户

    2.1创建add_user.py

    from flask import Blueprint, request, render_template, redirect
    from settings import USER_INFO
    
    add_user_app = Blueprint('add_user', '__name__')
    
    @add_user_app.route('/add_user', methods=['GET', 'POST'])
    def add_user():
        if request.method == 'POST':
            user = request.form.get('username')
            pwd = request.form.get('password')
            USER_INFO.append({user: pwd})
            return redirect('/show_page')
        else:
            return render_template('add_user.html')

     2.2在templates目录下创建add_user.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <form action="" method="post">
        <h3>新增用户界面</h3>
        用户名:<input type="text" name="username">
        密码:<input type="password" name="password">
        <button>新增</button>
    </form>
    </body>
    </html>
    add_user

    3、编辑用户

    3.1创建edit_user.py文件 

    from flask import Blueprint, render_template, request, redirect
    from settings import USER_INFO
    
    edit_user_app = Blueprint('edit_user', '__name__')
    
    @edit_user_app.route('/edit_user', methods=['GET', 'POST'])
    def edit_user():
        uid = int(request.args.get('id'))
        if request.method == 'POST':
            user = request.form.get('username')
            pwd = request.form.get('password')
            nlen = len(USER_INFO)
            if 0 > uid or uid >= nlen:
                return f'索引不存在,索引范围是:0-{nlen - 1}'
            else:
                USER_INFO[uid] = {user: pwd}
            return redirect('/show_page')
        else:
            user_info = USER_INFO[uid]
            return render_template('edit_user.html', user_info=user_info)

      3.2在templates目录下创建edit_user.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <form action="" method="post">
    <h3>编辑用户界面</h3>
        {% for user in user_info %}
        用户名:<input type="text" name="username" value="{{ user }}">
        密码:<input type="password" name="password" value="{{ user_info[user] }}">
        {% endfor %}
    
    
        <button>保存</button>
    </form>
    </body>
    </html>
    edit_user

    4、删除用户

    4.1创建del_user.py

    from flask import Blueprint,request,render_template,redirect
    from settings import USER_INFO
    
    del_user_app = Blueprint('del_user','__name__')
    
    @del_user_app.route('/del_user')
    def del_user():
        uid = int(request.args.get('id'))
        USER_INFO.pop(uid)
        return redirect('/show_page')

    5、创建damo_2.py主文件

    from flask import Flask, session, request, redirect, render_template
    from flask import session
    from show import show_app
    from index import index_app
    from add_user import add_user_app
    from del_user import del_user_app
    from edit_user import edit_user_app
    from login import login_app
    
    user_app = Flask('__name__')
    user_app.secret_key = '~!@#$%^&*'
    user_app.config['DEBUG'] = True
    
    @user_app.before_request
    def session_check():  # 中间件用户登陆认证,用户必须登录后才能访问展示页面
        if session.get('user') or request.path == '/login':
            return None
        else:
            return redirect('/login')
    @user_app.after_request
    def response_after(response):
        return response
    user_app.register_blueprint(index_app)     # 注册公共展示页面
    user_app.register_blueprint(show_app)      # 注册用户详情页面
    user_app.register_blueprint(add_user_app)  # 注册新增用户页面
    user_app.register_blueprint(del_user_app)  # 注册删除用户页面
    user_app.register_blueprint(edit_user_app) # 注册编辑用户页面
    user_app.register_blueprint(login_app)     # 注册用户登陆页面
    @user_app.errorhandler(404)                # 404错误页面
    def error404(error_msg):
        return render_template('error404.html')
    
    user_app.run()

     二、使用类的方式(CBV)

    1、修改展示页面show.py

    from flask import Blueprint, render_template
    from settings import USER_INFO
    from flask import views
    
    show_app = Blueprint('show_app',__name__)
    
    class ShowPage(views.MethodView):
        def get(self):
            return render_template('show_page.html', user_info=USER_INFO)
    
    show_app.add_url_rule('/show_page', view_func=ShowPage.as_view(name='show_page'))

    2、修改新增用户add_user.py

    from flask import Blueprint, request, render_template, redirect
    from settings import USER_INFO
    from flask import views
    
    add_user_app = Blueprint('add_user', '__name__')
    
    class AddUser(views.MethodView):
        def get(self):
            return render_template('add_user.html')
    
        def post(self):
            user = request.form.get('username')
            pwd = request.form.get('password')
            USER_INFO.append({user: pwd})
            return redirect('/show_page')
    add_user_app.add_url_rule('/add_user',view_func=AddUser.as_view(name='add_user'))

    3、修改编辑用户edit_user.py

    from flask import Blueprint, render_template, request, redirect
    from settings import USER_INFO
    from flask import views
    
    edit_user_app = Blueprint('edit_user', '__name__')
    
    class EditUser(views.MethodView):
        def get(self):
            uid = int(request.args.get('id'))
            user_info = USER_INFO[uid]
            return render_template('edit_user.html', user_info=user_info)
    
        def post(self):
            uid = int(request.args.get('id'))
            user = request.form.get('username')
            pwd = request.form.get('password')
            nlen = len(USER_INFO)
            if 0 > uid or uid >= nlen:
                return f'索引不存在,索引范围是:0-{nlen - 1}'
            else:
                USER_INFO[uid] = {user: pwd}
            return redirect('/show_page')
    edit_user_app.add_url_rule('/edit_user',view_func=EditUser.as_view(name='edit_view'))

     4、修改删除用户del_user.py

    from flask import Blueprint,request,render_template,redirect
    from settings import USER_INFO
    from flask import views
    del_user_app = Blueprint('del_user','__name__')
    
    class DelUser(views.MethodView):
        def get(self):
            uid = int(request.args.get('id'))
            USER_INFO.pop(uid)
            return redirect('/show_page')
    del_user_app.add_url_rule('/del_user',view_func=DelUser.as_view(name='del_user'))

     页面展示如下:

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  • 原文地址:https://www.cnblogs.com/caesar-id/p/10976613.html
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