flask组件 --- wtforms

1. 简介

　　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。

2. 安装

　　pip install wtforms

3. 使用----用户注册

　　注册页面需要让用户输入：用户名、密码、确认密码、性别、爱好、居住城市等.

form类: 

from flask import Flask,render_template,request,redirect
from wtforms import Form, widgets, validators
from wtforms.fields import simple   # 放比较简单的字段类型
from wtforms.fields import html5    # 放html相关的
from wtforms.fields import core     # 放比较核心的


class RegisterForm(Form):
    name = simple.StringField(
        label="用户名: ",
        render_kw={"class":"form-control"},
        default="默认的用户名",
        validators=[validators.DataRequired(message="姓名不能为空!"),]
    )

    passwd = simple.PasswordField(
        label="密码: ",
        validators=[validators.DataRequired(message="密码不能为空!"),]
    )

    re_passwd = simple.PasswordField(
        label="确认密码: ",
        validators=[
            validators.DataRequired(message="密码不能为空!"),
            validators.EqualTo("passwd",message="两次输入的密码不一致!")
        ]
    )

    email = html5.EmailField(
        label="邮箱: ",
        validators=[
            validators.Email(message="邮箱格式不正确!"),
            validators.DataRequired(message="邮箱不能为空!")
        ]
    )

    gender = core.RadioField(
        label="性别",
        choices=(
            (1,"男"),
            (2,"女")
        ),
        default=1,
        coerce=int
    )

    city = core.SelectField(
        label="居住城市",
        choices=(
            ("bj","北京"),
            ("ty","太原"),
        )
    )

    hobby = core.SelectMultipleField(
        label="爱好",
        choices=(
            (1,"game"),
            (2,"sport"),
            (3,"run")
        ),
        coerce=int,
        default=[1,2],
        widget=widgets.ListWidget(prefix_label=False),      # 整句表示将多选下拉框转为多选框, false表示框在文字前边
        option_widget=widgets.CheckboxInput()               # 表示将多选框转为可供点击选择的多选框
    )



class TestForm(Form):
    name = simple.StringField(
        label="姓名: "
    )
    level = core.SelectField(
        label="级别: ",
        choices=(),
        coerce=int
    )

    def __init__(self):
        super(TestForm, self).__init__()
        self.level.choices = fetch_all(sql="select id,lv_name from level",cursor_style=None)

视图函数:

@app.route("/register",methods=["get","post"])
def register():
    if request.method == "GET":
        myform = RegisterForm()
        return render_template("register.html",myform=myform)
    myform = RegisterForm(formdata=request.form)
    if myform.validate():
        print(myform.data)
        return redirect("/index")
    return render_template("register.html",myform=myform)

html模板:

<form action="" method="post" novalidate>
    {% for field in myform %}
    <p>{{ field.label }}{{ field }}{{ field.errors.0 }}</p>
    {% endfor %}
    <input type="submit" value="提交">
</form>

4. forms页面显示默认值

在视图函数中:

@app.route("/tt")
def test():
    if request.method == "GET":
        testform = TestForm(data={"level":"3","name":"eva"})    # 加入data参数, 即将data里面信息在页面上以默认值的形式显示出来
        return render_template("test.html",testform=testform)

显示效果:

5. 数据库更新同步到页面