4.2 表單類

from flask_wtf import Form
from wtforms import StringField, SubmitField
from wtforms.validators import Required, EqualTo
# 定義一個(gè)表單類
class NameForm(Form):
    name=StringField('what is you name', validators=[Required()])   # 創(chuàng)建一個(gè)type=text的input
    submit=SubmitField('Submit')                                    # 創(chuàng)建一個(gè)type=submit的input
    conPassword=StringField('confirm password', validators=[EqualTo('password', message='must match')])   # message好像必須有

WTForms支持的HTML標(biāo)準(zhǔn)字段

幾個(gè)比較特殊的字段示意：

class NameForm(Form):
    radioSex=RadioField('性別', choices=[('1', '男人'), ('2', '女人')])
    selectHobby=SelectField('愛(ài)好', choices=[('3', '足球'), ('4', '籃球'), ('5', '乒乓')])
    # radioSex: 表單radio元素的name值
    # 第一個(gè)引號(hào)內(nèi): label值
    # choises=[]: 數(shù)組內(nèi)'1'為value值

WTFroms驗(yàn)證函數(shù)

4.3 將表單渲染成HTML

{% extends "base.html" %} 
{% import "bootstrap/wtf.html" as wtf %} 
 
{% block title %}Flasky2b{% endblock %}
 
{% block page_content %} 
<div class="page-header"> 
    <h1>Hello, {% if name %}{{ name }}{% else %}Stranger{% endif %}!</h1> 
</div>
{#使用flask-bootstrap渲染表單#}
{{ wtf.quick_form(form) }} 
{% endblock %}

4.4 在視圖函數(shù)中處理表單

# -*- coding:utf-8 -*-

# 把 str 編碼由 ascii 改為 utf8
import sys
reload(sys)
sys.setdefaultencoding('utf8')
# 以下載入包
from flask import Flask, render_template
from flask_bootstrap import Bootstrap
from flask_moment import Moment              # 引入flask-moment
from datetime import datetime                # 引入datetime
from flask_wtf import Form
from wtforms import StringField,SubmitField,TextAreaField,IntegerField,BooleanField,RadioField,SelectField,FileField,PasswordField
from wtforms.validators import Required, email, EqualTo
app = Flask(__name__)
app.config['SECRET_KEY']="string hard"
bootstrap=Bootstrap(app)
moment=Moment(app)
# 定義一個(gè)表單類
class NameForm(Form):
    name=StringField('what is you name', validators=[Required()])        # 創(chuàng)建一個(gè)type="text"的input句旱，文本傳入label標(biāo)簽
    password=PasswordField('password')
    conPassword=StringField('confirm password', validators=[EqualTo('password', message='must match')])
    intro=TextAreaField('introduce yourself')
    email=StringField('input your email', validators=[email()])          # 必須是email格式
    integer=IntegerField('input an integer')
    booleanC=BooleanField('choose/let')
    radioSex=RadioField('性別', choices=[('1', '男人'), ('2', '女人')])   # 創(chuàng)建type="radio"單選框
    selectHobby=SelectField('愛(ài)好', choices=[('3', '足球'), ('4', '籃球'), ('5', '乒乓')]) #創(chuàng)建select下拉框
    submit=SubmitField('Submit')                                         # 創(chuàng)建一個(gè)type="submit"的input
    fileload=FileField('上傳文件')
# 在視圖函數(shù)中處理表單
@app.route('/', methods=['GET', 'POST'])
def hello_world():                      # 在視圖函數(shù)中要定義name變量和form變量
    name=None
    intro=None
    form=NameForm()                     # 實(shí)例化一個(gè)NameForm()類
    if form.validate_on_submit():       # 表單驗(yàn)證成功，validate_on_submit()方法返回True
        name=form.name.data             #
        intro=form.intro.data
        form.name.data=''
    return render_template("form.html",
                           name=name,
                           intro=intro,
                           current_time=datetime.utcnow(),
                           form=form,
                           )

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

4.5 重定向和用戶會(huì)話

不要讓web程序?qū)OST請(qǐng)求作為瀏覽器發(fā)送的最后一個(gè)請(qǐng)求;
使用重定向后晰奖，原先的name=form.name.data獲取的數(shù)據(jù)就丟失了谈撒，所以要將數(shù)據(jù)存儲(chǔ)在用戶會(huì)話中，session

from flask import Flask, render_template, session, redirect, url_for 
 
@app.route('/', methods=['GET', 'POST']) 
def index(): 
    form = NameForm() 
    if form.validate_on_submit(): 

        session['name'] = form.name.data 
        return redirect(url_for('index'))   # 生成HTTP重定向響應(yīng)匾南，參數(shù)是重定向的URL
    return render_template('index.html', form=form, name=session.get('name'))
    # 使用.get('name')讀取避免未找到鍵的異常情況

4.6 flash消息

在視圖函數(shù)中使用flash()會(huì)生成一個(gè)消息啃匿，F(xiàn)lask把get_flashed_messages()函數(shù)開(kāi)放給模板，用于模板中獲取并渲染消息

{% block content %}
<div class='container'>
    {% for message in get_flashed_messages() %}
        <div class='alert alert-warning'>
            <button type='button' class='close' data-dismiss='alert'>×</button>
            {{ message }}
        </div>
    {% endfor %}
</div>
{% endblock %}

from flask import Flask,render_template,session,redirect,url_for,flash

@app.route('/',mrthod=['GET', 'POST'])
def index():
    form=NameForm()
    if form.validate_on_submit():
        old_name=session.get('name')
        if old_name is not None and old_name != form.name.data:
            flash('you changed your name!')
        session('name')=form.name.data
        return redirect(url_for('index'))
    return render_template('index.html', form=form, name=session.get('name'))