异步发送邮件
app.py
import os
from threading import Thread
import sendgrid
from sendgrid.helpers.mail import Email as SGEmail, Content, Mail as SGMail
from flask_mail import Mail, Message
from flask_wtf import FlaskForm
from wtforms import StringField, TextAreaField, SubmitField
from wtforms.validators import DataRequired, Email
from flask import Flask, flash, redirect, url_for, render_template, request
app = Flask(name)
app.jinja_env.trim_blocks = True
app.jinja_env.lstrip_blocks = True
app.config.update(
SECRET_KEY=os.getenv('SECRET_KEY', 'secret string'),
MAIL_SERVER=os.getenv('MAIL_SERVER'),
MAIL_PORT=465,
MAIL_USE_SSL=True,
MAIL_USERNAME=os.getenv('MAIL_USERNAME'),
MAIL_PASSWORD=os.getenv('MAIL_PASSWORD'),
MAIL_DEFAULT_SENDER=('Grey Li', os.getenv('MAIL_USERNAME'))
)
mail = Mail(app)
send over SMTP
def send_smtp_mail(subject, to, body):
message = Message(subject, recipients=[to], body=body)
mail.send(message)
send over SendGrid Web API
def send_api_mail(subject, to, body):
sg = sendgrid.SendGridAPIClient(apikey=os.getenv('SENDGRID_API_KEY'))
from_email = SGEmail('Grey Li noreply@helloflask.com')
to_email = SGEmail(to)
content = Content("text/plain", body)
email = SGMail(from_email, subject, to_email, content)
sg.client.mail.send.post(request_body=email.get())
send email asynchronously
def _send_async_mail(app, message):
with app.app_context():
mail.send(message)
def send_async_mail(subject, to, body):
# app = current_app._get_current_object() # if use factory (i.e. create_app()), get app like this
message = Message(subject, recipients=[to], body=body)
thr = Thread(target=_send_async_mail, args=[app, message])
thr.start()
return thr
send email with HTML body
def send_subscribe_mail(subject, to, **kwargs):
message = Message(subject, recipients=[to], sender='Flask Weekly <%s>' % os.getenv('MAIL_USERNAME'))
message.body = render_template('emails/subscribe.txt', **kwargs)
message.html = render_template('emails/subscribe.html', **kwargs)
mail.send(message)
class EmailForm(FlaskForm):
to = StringField('To', validators=[DataRequired(), Email()])
subject = StringField('Subject', validators=[DataRequired()])
body = TextAreaField('Body', validators=[DataRequired()])
submit_smtp = SubmitField('Send with SMTP')
submit_api = SubmitField('Send with SendGrid API')
submit_async = SubmitField('Send with SMTP asynchronously')
class SubscribeForm(FlaskForm):
name = StringField('Name', validators=[DataRequired()])
email = StringField('Email', validators=[DataRequired(), Email()])
submit = SubmitField('Subscribe')
@app.route('/', methods=['GET', 'POST'])
def index():
form = EmailForm()
if form.validate_on_submit():
to = form.to.data
subject = form.subject.data
body = form.body.data
if form.submit_smtp.data:
send_smtp_mail(subject, to, body)
method = request.form.get('submit_smtp')
elif form.submit_api.data:
send_api_mail(subject, to, body)
method = request.form.get('submit_api')
else:
send_async_mail(subject, to, body)
method = request.form.get('submit_async')
flash('Email sent %s! Check your inbox.' % ' '.join(method.split()[1:]))
return redirect(url_for('index'))
form.subject.data = 'Hello, World!'
form.body.data = 'Across the Great Wall we can reach every corner in the world.'
return render_template('index.html', form=form)
@app.route('/subscribe', methods=['GET', 'POST'])
def subscribe():
form = SubscribeForm()
if form.validate_on_submit():
name = form.name.data
email = form.email.data
send_subscribe_mail('Subscribe Success!', email, name=name)
flash('Confirmation email have been sent! Check your inbox.')
return redirect(url_for('subscribe'))
return render_template('subscribe.html', form=form)
@app.route('/unsubscribe')
def unsubscribe():
flash('Want to unsubscribe? No way...')
return redirect(url_for('subscribe'))
subscribe.html
{% extends 'base.html' %}
{% from 'macros.html' import form_field %}
{% block content %}
<h2>Flask Weekly</h2>
<p>A free weekly newsletter featuring curated news, articles, new releases, jobs etc related to Flask. </p>
<p>Delivery at every Wednesday morning.</p>
<p>Unsubscribe at any time.</p>
<form method="post">
{{ form.csrf_token }}
{{ form_field(form.name, placeholder='Your Name') }}
{{ form_field(form.email, placeholder='Your Email') }}
{{ form.submit(class='btn') }}
</form>
{% endblock %}
index.html
{% extends 'base.html' %}
{% from 'macros.html' import form_field %}
{% block content %}
<h2>Send an Email to Yourself</h2>
<p>or subscribe <a href="{{ url_for('subscribe') }}">the fake newsletter</a></p>
<form method="post">
{{ form.csrf_token }}
{{ form_field(form.to, placeholder='zorn@example.com') }}
{{ form_field(form.subject, size=30) }}
{{ form_field(form.body, rows=5, cols=50) }}
{{ form.submit_smtp(class='btn') }}
{{ form.submit_api(class='btn') }}
{{ form.submit_async(class='btn') }}
</form>
{% endblock %}
macros.html
{% macro form_field(field) %}
{{ field.label }}
{% if field.flags.required -%}
{{ field(required='required', kwargs) }}
{%- else -%}
{{ field(kwargs) }}
{%- endif %}
{% if field.errors -%}
{% for error in field.errors -%}
<small class="error">{{ error }}</small>
{%- endfor %}
{%- endif %}
{% endmacro %}
base.html
<!DOCTYPE html>
<html>
<head>
{% block head %}
<meta charset="utf-8">
<title>{% block title %}Email - HelloFlask{% endblock %}</title>
<link rel="icon" type="image/x-icon" href="{{ url_for('static', filename='favicon.ico') }}">
{% block styles %}
<link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='style.css' ) }}">
{% endblock %}
{% endblock %}
</head>
<body>
<nav>
<ul>
<li><a href="{{ url_for('index') }}">Home</a></li>
</ul>
</nav>
<main>
{% for message in get_flashed_messages() %}
<div class="alert">
{{ message }}
</div>
{% endfor %}
{% block content %}{% endblock %}
</main>
<footer>
{% block footer %}
<small> © 2018 <a href="http://greyli.com" title="Written by Grey Li">Grey Li</a> /
<a href="https://github.com/greyli/helloflask" title="Fork me on GitHub">GitHub</a> /
<a href="http://helloflask.com" title="A HelloFlask project">HelloFlask</a>
</small>
{% endblock %}
</footer>
{% block scripts %}{% endblock %}
</body>
</html>
emails/subscribe.html subscribe.txt
<div style="width: 580px; padding: 20px;">
<h3>Hello {{ name }},</h3>
<p>Thank you for subscribing Flask Weekly!</p>
<p>Enjoy the reading :)</p>
<small style="color: #868e96;">
Click here to <a href="{{ url_for('unsubscribe', _external=True) }}">unsubscribe</a>.
</small>
</div>
subscribe.txt
Hello {{ name }},
Thank you for subscribing Flask Weekly!
Enjoy the reading :)
Visit this link to unsubscribe: {{ url_for('unsubscribe', _external=True) }}
static/style.css
body {
margin: auto;
width: 750px;
}
nav ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #333;
}
nav li {
float: left;
}
nav li a {
display: block;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
nav li a:hover {
background-color: #111;
}
main {
padding: 10px 20px;
}
footer {
font-size: 13px;
color: #888;
border-top: 1px solid #eee;
margin-top: 25px;
text-align: center;
padding: 20px;
}
.alert {
position: relative;
padding: 0.75rem 1.25rem;
margin-bottom: 1rem;
border: 1px solid #b8daff;
border-radius: 0.25rem;
color: #004085;
background-color: #cce5ff;
}
.btn {
font-size: 14px;
padding: 5px 10px;
text-decoration: none;
cursor: pointer;
background-color: white;
color: black;
border: 2px solid #555555;
}
.btn:hover {
text-decoration: none;
background-color: black;
color: white;
border: 2px solid black;
}
