JSON serialization

[Amertz08]

Not entirely sure what you can do about this but when using w/ Celery and the task serializer is set to json it blows up. Won't even send a base flask mail object.

kombu.exceptions.EncodeError: <flask_mail.Attachment object at 0x2b32810> is not JSON serializable

Had to do an ugly work around

# helpers.py
def send_template_email(subject, recipients, template_name, context, attachments=None):
    '''
    Sends async email with templates and optional attachments
    :param subject: Email subject.
    :param recipients: List of recipients.
    :param template_name: Name of template. Should be in templates/emails
    :param context: Template context variables
    :param attachments: List of dictionaries that describes attachments
    attachments = [
        {
            'type': 'csv',
            'loc': absolute path,
            'file_name': file name
        }
    ]
    :return: None
    '''
    with app.app_context():
        html = render_template('/emails/{}.html'.format(template_name), **context)
        text = render_template('/emails/{}.txt'.format(template_name), **context)

        msg = Message(
            subject=subject,
            recipients=recipients,
            body=text,
            html=html
        )

    send_email_async.delay(msg.__dict__, attachments)

# tasks.py
@celery.task
def send_email_async(data, attachments=None):
    with app.app_context():
        msg = Message()
        msg.__dict__.update(data)
        if attachments:
            for a in attachments:
                if a['type'] == 'csv':
                    csv_file = MIMEBase('application', 'octect-stream')
                    csv_file.set_payload(open(a['loc'], 'rb').read())
                    Encoders.encode_base64(csv_file)
                    csv_file.add_header('Content-Disposition', 'attachment', filename=a['file_name'])
                    msg.attach(csv_file)

        mail.send(msg)