Python Flask-表单提交方式

这篇文章讲两种表单提交方式,先说一下目录树,下图左侧

这里写图片描述

templates文件夹放置html文件,
static文件夹放置css,js文件.

1.请求上下文

首先在templates文件夹新建一个login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div align="center">
<h2>User Management</h2>
    {% if message %} {{message}} {% endif %}
    <form method="POST">

        <input type="text" name="username" placeholder="username">
        <br>
        <input type="password" name="password" placeholder="password">
        <br>
        <input type="submit" value="Submit">
        <input type="reset" value="reset">
    </form>
</div>

</body>
</html>

这里写图片描述

{% if message %} {{message}} {% endif %}用于输出登录失败时的错误信息,在form标签中添加提交方式<form method="POST">

然后新建一个login.py

from flask import Flask,request,render_template,redirect

app = Flask(__name__)
//绑定访问地址127.0.0.1:5000/user
@app.route("/user",methods=['GET','POST'])
def login():
    if request.method =='POST':
        username = request.form['username']
        password = request.form['password']
        if username =="user" and password=="password":
            return redirect("http://www.baidu.com")
        else:
            message = "Failed Login"
            return render_template('login1.html',message=message)
    return render_template('login1.html')

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

2.WTForm

这里对上面login1.html和login.py修改

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div align="center">
<h2>User Management</h2>
    {% if message %} {{message}} {% endif %}
    <form method="POST">
        username:{{form.username}}
        <br>
        password:{{form.password}}
        <br>
        <input type="submit" value="Submit">
        <input type="reset" value="reset">
    </form>
</div>

</body>
</html>

这里直接去掉了输入的input标签,换成了
username:{{form.username}},
password:{{form.password}} (jinja2模板)

from flask import Flask,request,render_template,redirect

app = Flask(__name__)

from wtforms import Form,TextField,PasswordField,validators

class LoginForm(Form):
    username = TextField("username",[validators.Required()])
    password = PasswordField("password",[validators.Required()])

@app.route("/user",methods=['GET','POST'])
def login():
    myForm = LoginForm(request.form)
    if request.method =='POST':
        if myForm.username.data =="user" and myForm.password.data=="password" and myForm.validate():
            return redirect("http://www.baidu.com")
        else:
            message = "Failed Login"
            return render_template('login1.html',message=message,form=myForm)
    return render_template('login1.html',form=myForm)

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

(1)from wtforms import Form,TextField,PasswordField,validators
从wtforms 导入Form类,所有自定义的表单都需要继承这个类,比如

class LoginForm(Form):

(2)一系列的Field对应html的input标签控件,validators是验证器,用于验证用户输入的数据.

myForm.password.data

以上代码用于获取用户输入的密码,这里验证中多了myForm.validate():

(3)创建一个对象,[validators.Required()]表明这个值必须要输入

username = TextField("username",[validators.Required()])

(4)在最后还需将myForm传入form
return render_template('login1.html',form=myForm)