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Zhang_derek(选择比努力更重要)

Flask信号和wtforms

一、信号

1.1.所有内置信号

request_started = _signals.signal('request-started')                # 请求到来前执行
request_finished = _signals.signal('request-finished')              # 请求结束后执行
 
before_render_template = _signals.signal('before-render-template')  # 模板渲染前执行
template_rendered = _signals.signal('template-rendered')            # 模板渲染后执行
 
got_request_exception = _signals.signal('got-request-exception')    # 请求执行出现异常时执行
 
request_tearing_down = _signals.signal('request-tearing-down')      # 请求执行完毕后自动执行(无论成功与否)
appcontext_tearing_down = _signals.signal('appcontext-tearing-down')# 请求上下文执行完毕后自动执行(无论成功与否)
 
appcontext_pushed = _signals.signal('appcontext-pushed')            # 请求上下文push时执行
appcontext_popped = _signals.signal('appcontext-popped')            # 请求上下文pop时执行
message_flashed = _signals.signal('message-flashed')                # 调用flask在其中添加数据时,自动触发

 

1.2.信号简单实例

Flask框架中的信号基于blinker,其主要就是让开发者可是在flask请求过程中定制一些用户行为。首先要安装blinker

pip install blinker
from flask import Flask,signals

app = Flask(__name__)
app.debug = True
app.secret_key = 'abcdef'

def func(*args,**kwargs):
    print('触发信号',args,kwargs)
signals.request_started.connect(func)

@app.route('/')
def index():
    print('hello')
    return 'hello world'

if __name__ == '__main__':
    app.run()

运行结果:

 

二、wtforms组件使用

2.1.安装

WTForms是一个支持多个web框架的form组件,主要用于对用户请求数据进行验证。安装方法

pip install wtforms

2.2.用户登录

 用户登录时,对用户名和密码进行验证

(1)app.py

from flask import Flask, render_template, request, redirect
from wtforms import Form
from wtforms.fields import simple
from wtforms import validators
from wtforms import widgets

app = Flask(__name__, template_folder='templates')
app.debug = True


class LoginForm(Form):
    name = simple.StringField(
        label='用户名',
        #自定义的验证规则
        validators=[
            validators.DataRequired(message='用户名不能为空.'),
            validators.Length(min=6, max=18, message='用户名长度必须大于%(min)d且小于%(max)d')
        ],
        #页面显示的插件
        widget=widgets.TextInput(),
        #加属性
        render_kw={'class': 'form-control'}
    )

    pwd = simple.PasswordField(
        label='密码',
        validators=[
            validators.DataRequired(message='密码不能为空.'),
            validators.Length(min=8, message='用户名长度必须大于%(min)d'),
            #正则表达式
            validators.Regexp(regex="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$@$!%*?&])[A-Za-z\d$@$!%*?&]{8,}",
                              message='密码至少8个字符,至少1个大写字母,1个小写字母,1个数字和1个特殊字符')

        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'GET':
        form = LoginForm()
        return render_template('login.html', form=form)
    else:
        form = LoginForm(formdata=request.form)
        if form.validate():
            print('用户提交数据通过格式验证,提交的值为:', form.data)
        else:
            print(form.errors)
        return render_template('login.html', form=form)

if __name__ == '__main__':
    app.run()

(2)login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>登录</h1>
<form method="post">

    <p>{{form.name.label}} {{form.name}} {{form.name.errors[0] }}</p>

    <p>{{form.pwd.label}} {{form.pwd}} {{form.pwd.errors[0] }}</p>
    <input type="submit" value="提交">
    
</form>
</body>
</html>

 

用户名和密码格式不对

 

2.3.用户注册

(1)app.py

from flask import Flask, render_template, request, redirect
from wtforms import Form
from wtforms.fields import core
from wtforms.fields import html5
from wtforms.fields import simple
from wtforms import validators
from wtforms import widgets

app = Flask(__name__, template_folder='templates')
app.debug = True



class RegisterForm(Form):
    name = simple.StringField(
        label='用户名',
        validators=[
            validators.DataRequired()
        ],
        widget=widgets.TextInput(),
        render_kw={'class': 'form-control'},
        default='derek'
    )

    pwd = simple.PasswordField(
        label='密码',
        validators=[
            validators.DataRequired(message='密码不能为空.')
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    pwd_confirm = simple.PasswordField(
        label='重复密码',
        validators=[
            validators.DataRequired(message='重复密码不能为空.'),
            #EqualTo:要跟那个字段一样
            validators.EqualTo('pwd', message="两次密码输入不一致")
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    email = html5.EmailField(
        label='邮箱',
        validators=[
            validators.DataRequired(message='邮箱不能为空.'),
            validators.Email(message='邮箱格式错误')
        ],
        widget=widgets.TextInput(input_type='email'),
        render_kw={'class': 'form-control'}
    )

    #RadiField单选
    gender = core.RadioField(
        label='性别',
        choices=(
            (1, ''),
            (2, ''),
        ),
        coerce=int      #因为前段提交过来的数据都是str格式,比如“1”,“2”,这里转换成int
    )
    #单选的下拉框
    city = core.SelectField(
        label='城市',
        choices=(
            ('bj', '北京'),
            ('sh', '上海'),
        )
    )
    #多选的下拉框
    hobby = core.SelectMultipleField(
        label='爱好',
        choices=(
            (1, '篮球'),
            (2, '足球'),
        ),
        coerce=int
    )

    favor = core.SelectMultipleField(
        label='喜好',
        choices=(
            (1, '篮球'),
            (2, '足球'),
        ),
        widget=widgets.ListWidget(prefix_label=False),
        option_widget=widgets.CheckboxInput(),   #多选
        coerce=int,
        default=[1, 2]
    )

    def __init__(self, *args, **kwargs):
        super(RegisterForm, self).__init__(*args, **kwargs)
        #重写默认的方法
        self.favor.choices = ((1, '篮球'), (2, '足球'), (3, '羽毛球'))

    #钩子函数
    def validate_pwd_confirm(self, field):
        """
        自定义pwd_confirm字段规则,例:与pwd字段是否一致
        :param field:
        :return:
        """
        # 最开始初始化时,self.data中已经有所有的值

        if field.data != self.data['pwd']:
            # raise validators.ValidationError("密码不一致") # 继续后续验证
            raise validators.StopValidation("密码不一致")  # 不再继续后续验证


@app.route('/register', methods=['GET', 'POST'])
def register():
    if request.method == 'GET':
        #data={'gender': 1 }  传到前端页面显示的默认值,这里只设置了gender,其它字段也可以通过这种方式设置
        form = RegisterForm(data={'gender': 1})
        return render_template('register.html', form=form)
    else:
        form = RegisterForm(formdata=request.form)
        if form.validate():
            print('用户提交数据通过格式验证,提交的值为:', form.data)
        else:
            print(form.errors)
        return render_template('register.html', form=form)



if __name__ == '__main__':
    app.run()

(2).register.html

可以直接循环取出所有字段

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>


<h1>用户注册</h1>
<form method="post" novalidate style="padding:0  50px">
    {% for item in form %}
    <p>{{item.label}}: {{item}} {{item.errors[0] }}</p>
    {% endfor %}
    <input type="submit" value="提交">

    
</form>
</body>
</html>

 

注册页面显示:

 

posted on 2018-05-13 14:06 zhang_derek 阅读(...) 评论(...) 编辑 收藏

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