Flask构建微电影视频网站(六)：后台管理模块

1.管理员登录

步骤：

• app/__ init __.py中创建db对象
• app/models.py中导入db对象
• app/admin/forms.py中定义表单验证
• app/templates/admin/login.html中使用表单字段、信息验证、消息闪现
• app/admin/views.py中出来登录请求、保存会话
• app/admin/views.py定义登录装饰器、访问控制

实际操作：

1.app/admin/forms.py中定义登录表单验证

# 安装Flask-WTF模块
# app/admin/forms.py
from flask_wtf import FlaskForm  
from wtforms import StringField, PasswordField, SubmitField
from wtforms.validators import DataRequired



class LoginForm(FlaskForm):
    """管理员登录表单"""
    account = StringField(
        label="账号",  # 字段名称
        # 账号不能为空
        validators=[
            DataRequired("请输入账号！")
        ],
        # 描述
        description="账号",
        # 附加选项，前端页面上除了name和type，其它属性都要加上
        render_kw={
            "class": "form-control",
            "placeholder": "请输入账号",
            # "required": "required",
        }
    )
    
    pwd = PasswordField(
        label="密码",
        validators=[
            DataRequired("请输入密码！")
        ],
        description="密码",
        render_kw={
            "class": "form-control",
            "placeholder": "请输入密码",
            # "required": "required",
        }
    )
    
    submit = SubmitField(
        '登录',
        render_kw = {
            "class": "btn btn-primary btn-block btn-flat",
        }
    )

2.替换html页面上的表单

# app/admin/views.py
@admin.route('/login')
def login():
    login_form = LoginForm()
    return render_template('admin/login.html', form=login_form)

# app/templates/admin/login.html
{{ form.account }} 替换 <input name="user" type="text" class="form-control" placeholder="请输入账号！">
    {{ from.pwd }} 替换<input name="pwd" type="password" class="form-control" placeholder="请输入密码！">
 {{ form.submit }} 替换<a id="btn-sub" type="submit" class="btn btn-primary btn-block btn-flat">登录</a>
 在{{ form.submit }}下面加个{{ form.csrf_token }}

# app/__init__.py
<!--令牌 -->
<!-->>> import uuid-->
<!-->>> uuid.uuid4().hex-->
<!--'ec0eba98fb9d472b95ce240b7ee8f4e2'-->
app.config['SECRET_KEY'] = 'ec0eba98fb9d472b95ce240b7ee8f4e2'

3.页面错误信息显示

# app/admin/views.py
@admin.route('/login', methods=["GET", "POST"])
def login():
    login_form = LoginForm()
    # 提交时验证
    if login_form .validate_on_submit():
        # 获取表单数据
        data = login_form .data
        
    return render_template('admin/login.html', form=login_form)

<!-- 页面显示错误信息 -->
<!--app/templates/admin/login.html-->
{% for err in form.account.errors %}
<div class="col-md-12" id="input_user">
    <font style="color:red">{{ err }}</font>
</div>
{% endfor %}


{% for err in form.pwd.errors %}
<div class="col-md-12" id="input_user">
    <font style="color:red">{{ err }}</font>
</div>
{% endfor %}

<!-- form表单不需要action -->

4.校验账号和密码

# app/admin/forms.py
from app.models import Admin
from wtforms.validators import ValidationError
# validate_字段名称
def validate_account(self, field):
    account = field.data
    # 统计admin条数
    admin = Admin.query.filter_by(name=account).count()
    # 判断是否有条数
    if admin == 0:
        raise ValidationError("账号不存在")

# app/admin/models.py
# 检测密码
def check_password(self, pwd):
    from werkzeug.security import check_password_hash
    return check_password_hash(self.pwd, pwd)

5.前端页面上显示登录错误信息，flash闪出

<!--app/admin/views.py-->
from app.models import Admin
from flask import flash, session, request
@admin.route('/login', methods=["GET", "POST"])
def login():
    login_form = LoginForm()
    # 提交时验证
    if login_form.validate_on_submit():
        # 获取表单数据
        data = form.data
        admin = Admin.query.filter_by(name=data["account"]).first()
        # 密码不正确
        if not admin.check_pwd(data["pwd"]):
            flash("密码错误！")
            return redirect(url_for("admin.login"))
        # 密码正确
        session["admin"] = data["account"]
        return redirect(request.args.get("next") or url_for("admin.index"))
    return render_template('admin/login.html', form=login_form)

<!--app/templates/admin/login.html-->
{% for msg in get_flashed_messages() %}
<p class="login-box-msg" style="color:red;">{{ msg }}</p>
{% endfor %}

6.退出系统

<!--app/admin/views.py-->
 @admin.route("/logout")
 def logout():
    session.pop("account", None)
    return redirect(url_for("admin.login")

7.装饰器限制访问

<!--app/admin/views.py-->
from functools import wraps

def admin_login_req(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
          if not session['admin'] is None:
                return redirect(url_for("admin.login", next=request.url))
          return f(*args, **kwargs)
    return decorated_function
# 装饰器写完之后，在后台的每个函数都要加上这个装饰器

8.依然能登录，解决bug

<!--app/admin/views.py-->
from funtools import wraps

def admin_login_req(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
          if "admin" not in session:
                return redirect(url_for("admin.login", next=request.url))
          return f(*args, **kwargs)
    return decorated_function

这样管理员的登录就完成了