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 %}
<h1>Sigh In</h1>
<form method="post" action="" name="login">
{{form.hidden_tag()}}
<p>
Please enter your OpenID:<br>
{{form.openid(size=80)}}<br>
</p>
<p>{{form.remember_me}} Remember Me</p>
<p><input type="submit" value="Sign In"></p>
</form>
{% 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
<html>
<head>
{% if title %}
<title>{{title}} - myblog</title>
{% else %}
<title>Welcome - myblog</title>
{% endif %}
</head>
<body>
<div>MyBlog:<a href="/index">Home</a></div>
<hr>
{% with messages = get_flashed_messages() %}
{% if messages %}
<ul>
{% for message in messages %}
<li>{{ message }}</li>
{% endfor %}
</ul>
{% endif %}
{% endwith %}
{% block content %}
{% endblock%}
</body>
</html>
修改 app/templates/login.html
{% extends "base.html" %}
{% block content %}
<h1>Sigh In</h1>
<form method="post" action="" name="login">
{{form.hidden_tag()}}
<p>
Please enter your OpenID:<br>
{{form.openid(size=80)}}<br>
{% for error in form.openid.errors %}
<span style="color:red;">[{{ error }}]</span>
{% endfor %}<br>
</p>
<p>{{form.remember_me}} Remember Me</p>
<p><input type="submit" value="Sign In"></p>
</form>
{% 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
