flask笔记：4：web表单

处理web表单表单需要Flask-WTF

在根目录创建一个配置文件

myblog/config.py

CSRF_ENABLED=True
SECRET_KEY='you-will-never-guess'

CSRF_ENABLED配置是为了激活跨站点请求伪造保护

SECRET_KEY是当CSRF激活后，建立一个加密令牌，用于验证表单

修改app/__init__.py

from flask import Flask
app=Flask(__name__)
app.config.from_object('config')
from app import views
#读取配置文件

编写第一个表单

app/forms.py

from flask.ext.wtf import Form
from wtforms import StringField,BooleanField
from wtforms.validators import DataRequired
class LoginForm(Form):
    openid = StringField('openid',validators=[DataRequired()])
    remember_me = BooleanField('remember_me',default=False)

导入所需的模块

创建一个Form类

定义一个openid文本框(StringField)，名字是openid，需要验证是否为空validators=[DataRequired()]

定义一个remember_me选择框(BooleanField )，名字remember_me，默认是False

创建表单模板

app/templates/login.html

{% extends "base.html" %}
{% block content %}
Sigh In

    {{form.hidden_tag()}}
    

        Please enter your OpenID:

        {{form.openid(size=80)}}

    
    
{{form.remember_me}} Remember Me
    


{% endblock %}

{{form.hidden_tag()}} 用来实现在配置中的CSRF保护，如果已经激活CSRF，这个字段要出现在所有表单中

{{form.openid(size=80)}} form表单的openid字段，输入框大小80

表单视图

修改 app/views.py

from flask import render_template
from app import app
from .forms import LoginForm

@app.route('/')
@app.route('/index')
def index ():
    user={'nickname':'Bob'}
    posts=[
            {'author':{'nickname':'John'},
             'body':'Beautiful day in Portland!'},
            {'author':{'nickname':'Susan'},
             'body':'The Avengers movie was so cool!'}
           ]
    return render_template("index.html",
    title="Home",
    user=user,
    posts=posts)

@app.route('/login',methods=['GET','POST'])
def login ():
    form = LoginForm()
    return render_template("login.html",
    title = "Sign In",
    form = form)
#导入LoginForm，视图接受GET和POST请求
#实例化一个LoginForm

接收表单数据

修改 app/views.py

from flask import render_template,flash,redirect
from app import app
from .forms import LoginForm

@app.route('/')
@app.route('/index')
def index ():
    user={'nickname':'Bob'}
    posts=[
            {'author':{'nickname':'John'},
             'body':'Beautiful day in Portland!'},
            {'author':{'nickname':'Susan'},
             'body':'The Avengers movie was so cool!'}
           ]
    return render_template("index.html",
    title="Home",
    user=user,
    posts=posts)

@app.route('/login',methods=['GET','POST'])
def login ():
    form = LoginForm()
    if form.validate_on_submit():
        flash('login requested for OpenID="'+form.openid.data+'",remember_me='+str(form.remember_me.data))
        return redirect('/index')
    return render_template("login.html",
    title = "Sign In",
    form = form)
#form.validate_on_submit()判断是否提交
#提交后用flash( )传递数据
#redirect( )是url跳转

修改 app/templates/base.html

    
        {% if title %}
        
        {% else %}
        
        {% endif %}
    
    
        
MyBlog:Home
        

        {% with messages = get_flashed_messages() %}
        {% if messages %}
        

            {% for message in messages %}
            
{{ message }}
            {% endfor %}
        
        {% endif %}
        {% endwith %}
        {% block content %}
        {% endblock%}
    

修改 app/templates/login.html

{% extends "base.html" %}
{% block content %}
Sigh In

    {{form.hidden_tag()}}
    

        Please enter your OpenID:

        {{form.openid(size=80)}}

        {% for error in form.openid.errors %}
        [{{ error }}]
        {% endfor %}

    
    
{{form.remember_me}} Remember Me
    


{% endblock %}

显示：

不输入直接提交会显示错误，这个是程序自带的错误提示，就是form.openid.errors

在输入框输入bob，选中remember_me

在index页面显示出提交的内容