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Send Appointment Reminders with Python and Django

(information)

Info

Ahoy! We now recommend you build your appointment reminders with Twilio's built-in Message Scheduling functionality. Head on over to the Message Scheduling documentation to learn more about scheduling messages.

Ready to implement SMS appointment reminders in your Django web application? We'll use the Twilio Python Helper Library and Twilio SMS API to push out reminders to our customers when appointments are near. Here's how it works at a high level:

An administrator (our user) creates an appointment for a future date and time, and stores a customer's phone number in the database for that appointment
When that appointment is saved a background task is scheduled to send a reminder to that customer before their appointment starts
At a configured time in advance of the appointment, the background task sends an SMS reminder to the customer to remind them of their appointment

Check out how Yelp uses SMS to confirm restaurant reservations for diners.

Appointment Reminder Building Blocks

Here are the technologies we'll use:

Django to create a database-driven web application
The Messages Resource from Twilio's REST API to send text messages
Dramatiq to help us schedule and execute background tasks on a recurring basis

How To Read This Tutorial

To implement appointment reminders, we will be working through a series of user stories that describe how to fully implement appointment reminders in a web application.

We'll walk through the code required to satisfy each story, and explore what we needed to add at each step.

All this can be done with the help of Twilio in under half an hour.

Meet our Django Appointment Reminder Stack

We're building this app for Django 2.1 on Python 3.7. We're big fans of Two Scoops of Django and we will use many best practices outlined there.

In addition to Dramatiq, we will use a few other Python libraries to make our task easier:

The twilio-python Python helper library
django-timezone-field to give us a model field for storing time zones
django-bootstrap3 and django-forms-bootstrap to make our form templates prettier
The fantastic arrow library to make our datetime math foolproof

We will also use PostgreSQL for our database and Redis as our Dramatiq message broker.

Project dependencies

1appdirs==1.4.3
2appnope==0.1.0
3arrow==0.15.7
4asgiref==3.2.5
5attrs==19.3.0
6backcall==0.1.0
7black==19.10b0
8certifi==2019.11.28
9cfgv==3.1.0
10chardet==3.0.4
11click==7.1.1
12decorator==4.4.2
13distlib==0.3.0
14Django==3.0.4
15django-dramatiq==0.9.1
16django-bootstrap3==14.0.0
17django-environ==0.4.5
18django-forms-bootstrap==3.1.0
19django-timezone-field==4.0
20dramatiq[rabbitmq,watch]==1.9.0
21entrypoints==0.3
22filelock==3.0.12
23flake8==3.7.9
24identify==1.4.11
25idna==2.9
26importlib-metadata==1.5.0
27ipdb==0.13.2
28ipython==7.13.0
29ipython-genutils==0.2.0
30isort==4.3.21
31jedi==0.16.0
32mccabe==0.6.1
33mock==4.0.2
34model-mommy==2.0.0
35nodeenv==1.3.5
36parso==0.6.2
37pathspec==0.7.0
38pexpect==4.8.0
39pickleshare==0.7.5
40pre-commit==2.2.0
41prompt-toolkit==3.0.4
42ptyprocess==0.6.0
43pycodestyle==2.5.0
44pyflakes==2.1.1
45Pygments==2.6.1
46PyJWT==1.7.1
47pytz==2019.3
48PyYAML==5.3
49redis==3.5.3
50regex==2020.2.20
51requests==2.23.0
52selenium==3.141.0
53six==1.14.0
54sqlparse==0.3.1
55toml==0.10.0
56traitlets==4.3.3
57twilio==6.36.0
58typed-ast==1.4.1
59urllib3==1.25.8
60virtualenv==20.0.10
61wcwidth==0.1.8
62whitenoise==5.1.0
63zipp==3.1.0

Now that we have all our depenencies defined, we can get started with our first user story: creating a new appointment.

Creating an Appointment

As a user, I want to create an appointment with a name, guest phone number, and a time in the future.

To build an automated appointment reminder app, we probably should start with an appointment. This story requires that we create a model object and a bit of the user interface to create and save a new Appointment in our system.

At a high level, here's what we will need to add:

An Appointment model to store information we need to send the reminder
A view to render our form and accept POST data from it
An HTML form to enter details about the appointment

Alright, so we know what we need to create a new appointment. Now let's start by looking at the model, where we decide what information we want to store with the appointment.

The Appointment Model

We only need to store four pieces of data about each appointment to send a reminder:

The customer's name
Their phone number
The date and time of their appointment
The time zone of the appointment

We also included two additional fields: task_id and created. The task_id field will help us keep track of the corresponding reminder task for this appointment. The created field is just a timestamp populated when an appointment is created.

Finally, we defined a __str__ method to tell Django how to represent instances of our model as text. This method uses the primary key and the customer's name to create a readable representation of an appointment.

Appointment model fields

reminders/models.py

1from __future__ import unicode_literals
2
3import redis
4
5from django.core.exceptions import ValidationError
6from django.conf import settings
7from django.db import models
8from django.urls import reverse
9from six import python_2_unicode_compatible
10from timezone_field import TimeZoneField
11
12import arrow
13
14
15@python_2_unicode_compatible
16class Appointment(models.Model):
17    name = models.CharField(max_length=150)
18    phone_number = models.CharField(max_length=15)
19    time = models.DateTimeField()
20    time_zone = TimeZoneField(default='UTC')
21
22    # Additional fields not visible to users
23    task_id = models.CharField(max_length=50, blank=True, editable=False)
24    created = models.DateTimeField(auto_now_add=True)
25
26    def __str__(self):
27        return 'Appointment #{0} - {1}'.format(self.pk, self.name)
28
29    def get_absolute_url(self):
30        return reverse('reminders:view_appointment', args=[str(self.id)])
31
32    def clean(self):
33        """Checks that appointments are not scheduled in the past"""
34
35        appointment_time = arrow.get(self.time, self.time_zone.zone)
36
37        if appointment_time < arrow.utcnow():
38            raise ValidationError(
39                'You cannot schedule an appointment for the past. '
40                'Please check your time and time_zone')
41
42    def schedule_reminder(self):
43        """Schedule a Dramatiq task to send a reminder for this appointment"""
44
45        # Calculate the correct time to send this reminder
46        appointment_time = arrow.get(self.time, self.time_zone.zone)
47        reminder_time = appointment_time.shift(minutes=-30)
48        now = arrow.now(self.time_zone.zone)
49        milli_to_wait = int(
50            (reminder_time - now).total_seconds()) * 1000
51
52        # Schedule the Dramatiq task
53        from .tasks import send_sms_reminder
54        result = send_sms_reminder.send_with_options(
55            args=(self.pk,),
56            delay=milli_to_wait)
57
58        return result.options['redis_message_id']
59
60    def save(self, *args, **kwargs):
61        """Custom save method which also schedules a reminder"""
62
63        # Check if we have scheduled a reminder for this appointment before
64        if self.task_id:
65            # Revoke that task in case its time has changed
66            self.cancel_task()
67
68        # Save our appointment, which populates self.pk,
69        # which is used in schedule_reminder
70        super(Appointment, self).save(*args, **kwargs)
71
72        # Schedule a new reminder task for this appointment
73        self.task_id = self.schedule_reminder()
74
75        # Save our appointment again, with the new task_id
76        super(Appointment, self).save(*args, **kwargs)
77
78    def cancel_task(self):
79        redis_client = redis.Redis(host=settings.REDIS_LOCAL, port=6379, db=0)
80        redis_client.hdel("dramatiq:default.DQ.msgs", self.task_id)

Our appointment model is now setup, the next step is writting a view for it.

New Appointment View

Django lets developers write views as functions or classes.

Class-based views are great when your views need to support CRUD-like features - perfect for our appointments project.

To make a view for creating new Appointment objects, we'll use Django's generic CreateView class.

All we need to specify is the model it should use and what fields it should include. We don't even need to declare a form - Django will use a ModelForm for us behind the scenes.

Success messages

Our view is ready to go with just those first three lines of code, but we'll make it a little better by adding the SuccessMessageMixin.

This mixin tells our view to pass the success_message property of our class to the Django messages framework after a successful creation. We will display those messages to the user in our templates.

Create new Appointment

reminders/views.py

1from django.contrib.messages.views import SuccessMessageMixin
2from django.urls import reverse_lazy
3from django.views.generic import DetailView
4from django.views.generic.edit import CreateView
5from django.views.generic.edit import DeleteView
6from django.views.generic.edit import UpdateView
7from django.views.generic.list import ListView
8
9from .models import Appointment
10
11
12class AppointmentListView(ListView):
13    """Shows users a list of appointments"""
14
15    model = Appointment
16
17
18class AppointmentDetailView(DetailView):
19    """Shows users a single appointment"""
20
21    model = Appointment
22
23
24class AppointmentCreateView(SuccessMessageMixin, CreateView):
25    """Powers a form to create a new appointment"""
26
27    model = Appointment
28    fields = ['name', 'phone_number', 'time', 'time_zone']
29    success_message = 'Appointment successfully created.'
30
31
32class AppointmentUpdateView(SuccessMessageMixin, UpdateView):
33    """Powers a form to edit existing appointments"""
34
35    model = Appointment
36    fields = ['name', 'phone_number', 'time', 'time_zone']
37    success_message = 'Appointment successfully updated.'
38
39
40class AppointmentDeleteView(DeleteView):
41    """Prompts users to confirm deletion of an appointment"""
42
43    model = Appointment
44    success_url = reverse_lazy('list_appointments')

Now that we have a view to create new appointments, we need to add a new URL to our URL dispatcher so users can get to it.

Wiring up the URLs

To satisfy the appointment creation user story, we'll create a new URL at /new and point it to our AppointmentCreateView.

Because we're using a class-based view, we pass our view to our URL with the .as_view() method instead of just using the view's name.

Wire up URL with create Appointment view

reminders/urls.py

1from django.conf.urls import re_path
2
3from .views import (
4    AppointmentCreateView,
5    AppointmentDeleteView,
6    AppointmentDetailView,
7    AppointmentListView,
8    AppointmentUpdateView,
9)
10
11urlpatterns = [
12    # List and detail views
13    re_path(r'^$', AppointmentListView.as_view(), name='list_appointments'),
14    re_path(r'^(?P<pk>[0-9]+)$',
15            AppointmentDetailView.as_view(),
16            name='view_appointment'),
17
18    # Create, update, delete
19    re_path(r'^new$', AppointmentCreateView.as_view(), name='new_appointment'),
20    re_path(r'^(?P<pk>[0-9]+)/edit$',
21            AppointmentUpdateView.as_view(),
22            name='edit_appointment'),
23    re_path(r'^(?P<pk>[0-9]+)/delete$',
24            AppointmentDeleteView.as_view(),
25            name='delete_appointment'),
26]

With a view and a model in place, the last big piece we need to let our users create new appointments is the HTML form.

New Appointment Form

Our form template inherits from our base template, which you can check out at templates/base.html.

We're using Bootstrap for the front end of our app, and we use the django-forms-bootstrap library to help us render our form with the |as_bootstrap_horizontal template filter.

By naming this file appointment_form.html, our AppointmentCreateView will automatically use this template when rendering its response. If you want to name your template something else, you can specify its name by adding a template_name property on our view class.

New Appointment form

templates/reminders/appointment_form.html

1{% extends "base.html" %}
2
3{% load bootstrap_tags %}
4
5{% block title %}New reminder{% endblock title %}
6
7{% block content %}
8  <div class="row">
9    <div class="col-lg-9">
10      <div class="page-header">
11        <h1>
12          {% if not object.pk %}
13            New appointment
14          {% else %}
15            Edit appointment
16          {% endif %}
17          </h1>
18      </div>
19
20      <form class="form-horizontal" method="post">
21        {% csrf_token %}
22        {{ form|as_bootstrap_horizontal }}
23        <div class="form-group">
24          <div class="col-sm-offset-2 col-sm-10">
25            <a href="#back" class="btn btn-default">Cancel</a>
26            <button type="submit" class="btn btn-primary">
27              {% if not object.pk %}
28                Create appointment
29              {% else %}
30                Update appointment
31              {% endif %}
32            </button>
33          </div>
34        </div>
35      </form>
36    </div>
37  </div>
38{% endblock %}
39
40{% block page_css %}
41  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/css/bootstrap-datetimepicker.min.css" />
42{% endblock %}
43
44{% block page_js %}
45  <script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.3/moment.min.js"></script>
46  <script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/js/bootstrap-datetimepicker.min.js"></script>
47
48  <script type="text/javascript">
49      $(function() {
50          $('#id_time').datetimepicker({
51            format: 'MM/DD/YYYY HH:mm',
52            extraFormats: ['YYYY-MM-DD HH:mm:ss'],
53            sideBySide: true
54          });
55      });
56  </script>
57{% endblock %}

We are not leaving this form yet. Instead, let's take a closer look at one of its widgets: the datepicker.

Appointment Form Datepicker

To make it easier for our users to enter the date and time of an appointment, we'll use a JavaScript datepicker widget.

In this case, bootstrap-datetimepicker is a good fit. We include the necessary CSS and JS files from content delivery networks and then add a little custom JavaScript to initialize the widget on the form input for our time field.

templates/reminders/appointment_form.html

1{% extends "base.html" %}
2
3{% load bootstrap_tags %}
4
5{% block title %}New reminder{% endblock title %}
6
7{% block content %}
8  <div class="row">
9    <div class="col-lg-9">
10      <div class="page-header">
11        <h1>
12          {% if not object.pk %}
13            New appointment
14          {% else %}
15            Edit appointment
16          {% endif %}
17          </h1>
18      </div>
19
20      <form class="form-horizontal" method="post">
21        {% csrf_token %}
22        {{ form|as_bootstrap_horizontal }}
23        <div class="form-group">
24          <div class="col-sm-offset-2 col-sm-10">
25            <a href="#back" class="btn btn-default">Cancel</a>
26            <button type="submit" class="btn btn-primary">
27              {% if not object.pk %}
28                Create appointment
29              {% else %}
30                Update appointment
31              {% endif %}
32            </button>
33          </div>
34        </div>
35      </form>
36    </div>
37  </div>
38{% endblock %}
39
40{% block page_css %}
41  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/css/bootstrap-datetimepicker.min.css" />
42{% endblock %}
43
44{% block page_js %}
45  <script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.3/moment.min.js"></script>
46  <script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/js/bootstrap-datetimepicker.min.js"></script>
47
48  <script type="text/javascript">
49      $(function() {
50          $('#id_time').datetimepicker({
51            format: 'MM/DD/YYYY HH:mm',
52            extraFormats: ['YYYY-MM-DD HH:mm:ss'],
53            sideBySide: true
54          });
55      });
56  </script>
57{% endblock %}

Now let's go back to our Appointment model to see what happens after we successfully post this form.

Add a get_absolute_url() Method

When a user clicks "Submit" on our new appointment form, their input will be received by our AppointmentCreateView and then validated against the fields we specified in our Appointment model.

If everything looks good, Django will save the new appointment to the database. We need to tell our AppointmentCreateView where to send our user next.

We could specify a success_url property on our AppointmentCreateView, but by default Django's CreateView class will use the newly created object's get_absolute_url method to figure out where to go next.

So we'll define a get_absolute_url method on our Appointment model, which uses Django's reverse utility function to build a URL for this appointment's detail page. You can see that template at templates/reminders/appointment_detail.html.

And now our users are all set to create new appointments.

get_absolute_url method

reminders/models.py

1from __future__ import unicode_literals
2
3import redis
4
5from django.core.exceptions import ValidationError
6from django.conf import settings
7from django.db import models
8from django.urls import reverse
9from six import python_2_unicode_compatible
10from timezone_field import TimeZoneField
11
12import arrow
13
14
15@python_2_unicode_compatible
16class Appointment(models.Model):
17    name = models.CharField(max_length=150)
18    phone_number = models.CharField(max_length=15)
19    time = models.DateTimeField()
20    time_zone = TimeZoneField(default='UTC')
21
22    # Additional fields not visible to users
23    task_id = models.CharField(max_length=50, blank=True, editable=False)
24    created = models.DateTimeField(auto_now_add=True)
25
26    def __str__(self):
27        return 'Appointment #{0} - {1}'.format(self.pk, self.name)
28
29    def get_absolute_url(self):
30        return reverse('reminders:view_appointment', args=[str(self.id)])
31
32    def clean(self):
33        """Checks that appointments are not scheduled in the past"""
34
35        appointment_time = arrow.get(self.time, self.time_zone.zone)
36
37        if appointment_time < arrow.utcnow():
38            raise ValidationError(
39                'You cannot schedule an appointment for the past. '
40                'Please check your time and time_zone')
41
42    def schedule_reminder(self):
43        """Schedule a Dramatiq task to send a reminder for this appointment"""
44
45        # Calculate the correct time to send this reminder
46        appointment_time = arrow.get(self.time, self.time_zone.zone)
47        reminder_time = appointment_time.shift(minutes=-30)
48        now = arrow.now(self.time_zone.zone)
49        milli_to_wait = int(
50            (reminder_time - now).total_seconds()) * 1000
51
52        # Schedule the Dramatiq task
53        from .tasks import send_sms_reminder
54        result = send_sms_reminder.send_with_options(
55            args=(self.pk,),
56            delay=milli_to_wait)
57
58        return result.options['redis_message_id']
59
60    def save(self, *args, **kwargs):
61        """Custom save method which also schedules a reminder"""
62
63        # Check if we have scheduled a reminder for this appointment before
64        if self.task_id:
65            # Revoke that task in case its time has changed
66            self.cancel_task()
67
68        # Save our appointment, which populates self.pk,
69        # which is used in schedule_reminder
70        super(Appointment, self).save(*args, **kwargs)
71
72        # Schedule a new reminder task for this appointment
73        self.task_id = self.schedule_reminder()
74
75        # Save our appointment again, with the new task_id
76        super(Appointment, self).save(*args, **kwargs)
77
78    def cancel_task(self):
79        redis_client = redis.Redis(host=settings.REDIS_LOCAL, port=6379, db=0)
80        redis_client.hdel("dramatiq:default.DQ.msgs", self.task_id)

We are now able to create new appointments. Nex, let's quickly implement a few other basic features: listing, updating, and deleting appointments.

Interacting with Appointments

As a user, I want to view a list of all future appointments, and be able to edit and delete those appointments.

If you're an organization that handles a lot of appointments, you probably want to be able to view and manage them in a single interface. That's what we'll tackle in this user story. We'll create a UI to:

Show all appointments
Edit individual appointments
Delete individual appointments

Because these are basic CRUD-like operations, we'll keep using Django's generic class-based views to save us a lot of work.

Interacting with appointments

reminders/views.py

1from django.contrib.messages.views import SuccessMessageMixin
2from django.urls import reverse_lazy
3from django.views.generic import DetailView
4from django.views.generic.edit import CreateView
5from django.views.generic.edit import DeleteView
6from django.views.generic.edit import UpdateView
7from django.views.generic.list import ListView
8
9from .models import Appointment
10
11
12class AppointmentListView(ListView):
13    """Shows users a list of appointments"""
14
15    model = Appointment
16
17
18class AppointmentDetailView(DetailView):
19    """Shows users a single appointment"""
20
21    model = Appointment
22
23
24class AppointmentCreateView(SuccessMessageMixin, CreateView):
25    """Powers a form to create a new appointment"""
26
27    model = Appointment
28    fields = ['name', 'phone_number', 'time', 'time_zone']
29    success_message = 'Appointment successfully created.'
30
31
32class AppointmentUpdateView(SuccessMessageMixin, UpdateView):
33    """Powers a form to edit existing appointments"""
34
35    model = Appointment
36    fields = ['name', 'phone_number', 'time', 'time_zone']
37    success_message = 'Appointment successfully updated.'
38
39
40class AppointmentDeleteView(DeleteView):
41    """Prompts users to confirm deletion of an appointment"""
42
43    model = Appointment
44    success_url = reverse_lazy('list_appointments')

We have the high level view of the task, so let's start with listing all the upcoming appointments.

Showing a List of Appointments

Django's ListView class was born for this.

All we need to do it's to point it at our Appointment model and it will handle building a QuerySet of all appointments for us.

1from .views import AppointmentListView
2
3re_path(r'^$', AppointmentListView.as_view(), name='list_appointments'),

List appointments

reminders/views.py

1from django.contrib.messages.views import SuccessMessageMixin
2from django.urls import reverse_lazy
3from django.views.generic import DetailView
4from django.views.generic.edit import CreateView
5from django.views.generic.edit import DeleteView
6from django.views.generic.edit import UpdateView
7from django.views.generic.list import ListView
8
9from .models import Appointment
10
11
12class AppointmentListView(ListView):
13    """Shows users a list of appointments"""
14
15    model = Appointment
16
17
18class AppointmentDetailView(DetailView):
19    """Shows users a single appointment"""
20
21    model = Appointment
22
23
24class AppointmentCreateView(SuccessMessageMixin, CreateView):
25    """Powers a form to create a new appointment"""
26
27    model = Appointment
28    fields = ['name', 'phone_number', 'time', 'time_zone']
29    success_message = 'Appointment successfully created.'
30
31
32class AppointmentUpdateView(SuccessMessageMixin, UpdateView):
33    """Powers a form to edit existing appointments"""
34
35    model = Appointment
36    fields = ['name', 'phone_number', 'time', 'time_zone']
37    success_message = 'Appointment successfully updated.'
38
39
40class AppointmentDeleteView(DeleteView):
41    """Prompts users to confirm deletion of an appointment"""
42
43    model = Appointment
44    success_url = reverse_lazy('list_appointments')

Our view is ready, now let's check out the template to display this list of appointments.

Appointment List Template

Our AppointmentListView passes its list of appointment objects to our template in the object_list variable.

If that variable is empty, we include a <p> tag saying there are no upcoming appointments.

Otherwise we populate a table with a row for each appointment in our list. We can use our handy get_absolute_url method again to include a link to each appointment's detail page.

We also use the {% url %} template tag to include links to our edit and delete views.

Render Appointment list

templates/reminders/appointment_list.html

1{% extends "base.html" %}
2
3{% block title %}Upcoming reminders{% endblock title %}
4
5{% block content %}
6  <div class="row">
7    <div class="col-lg-9">
8
9      <div class="page-header">
10        <h1>Appointments</h1>
11      </div>
12
13      {% if not object_list %}
14        <p><strong>No upcoming appointments.</strong> Why not <a href="{% url 'new_appointment' %}">schedule one?</a>
15      {% endif %}
16
17      <table class="table table-striped">
18        <thead>
19          <tr>
20            <th>Id</th>
21            <th>Name</th>
22            <th>Phone number</th>
23            <th>Time</th>
24            <th>Created at</th>
25            <th>Actions</th>
26          </tr>
27        </thead>
28        <tbody>
29          {% for appointment in object_list %}
30            <tr>
31              <td><a href="{{ appointment.get_absolute_url }}">{{ appointment.pk }}</a></td>
32              <td>{{ appointment.name }}</td>
33              <td>{{ appointment.phone_number }}</td>
34              <td>{{ appointment.time }}</td>
35              <td>{{ appointment.created }}</td>
36              <td>
37                <a class="btn btn-default btn-xs" href="{% url 'edit_appointment' appointment.pk %}">Edit</a>
38                <a class="btn btn-xs btn-danger" href="{% url 'delete_appointment' appointment.pk %}">Delete</a>
39              </td>
40            </tr>
41          {% endfor %}
42        </tbody>
43      </table>
44
45      <a class="btn btn-primary" href="{% url 'new_appointment' %}">New</a>
46    </div>
47  </div>
48{% endblock %}

And now that our appointment listing requirement is complete, let's see how we can use the new Appointment form to update existing appointments.

Tweaking our Form Template

Django's UpdateView allows you to add a view for updating appointments. Our form template needs a few tweaks, though, to handle prepopulated data from an existing appointment.

Django will store our datetimes precisely, down to the second, but we don't want to bother our users by forcing them to pick the precise second an appointment starts.

To fix this problem we use the extraFormats configuration option of bootstrap-datetimepicker.

By configuring our datetimepicker with a format value that doesn't ask users for seconds, and an extraFormat value that does accept datetimes with seconds, our form will populate correctly when Django provides a full datetime to our template.

Tweaking new Appointment form

templates/reminders/appointment_form.html

1{% extends "base.html" %}
2
3{% load bootstrap_tags %}
4
5{% block title %}New reminder{% endblock title %}
6
7{% block content %}
8  <div class="row">
9    <div class="col-lg-9">
10      <div class="page-header">
11        <h1>
12          {% if not object.pk %}
13            New appointment
14          {% else %}
15            Edit appointment
16          {% endif %}
17          </h1>
18      </div>
19
20      <form class="form-horizontal" method="post">
21        {% csrf_token %}
22        {{ form|as_bootstrap_horizontal }}
23        <div class="form-group">
24          <div class="col-sm-offset-2 col-sm-10">
25            <a href="#back" class="btn btn-default">Cancel</a>
26            <button type="submit" class="btn btn-primary">
27              {% if not object.pk %}
28                Create appointment
29              {% else %}
30                Update appointment
31              {% endif %}
32            </button>
33          </div>
34        </div>
35      </form>
36    </div>
37  </div>
38{% endblock %}
39
40{% block page_css %}
41  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/css/bootstrap-datetimepicker.min.css" />
42{% endblock %}
43
44{% block page_js %}
45  <script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.3/moment.min.js"></script>
46  <script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.7.14/js/bootstrap-datetimepicker.min.js"></script>
47
48  <script type="text/javascript">
49      $(function() {
50          $('#id_time').datetimepicker({
51            format: 'MM/DD/YYYY HH:mm',
52            extraFormats: ['YYYY-MM-DD HH:mm:ss'],
53            sideBySide: true
54          });
55      });
56  </script>
57{% endblock %}

We now have everything to List, Create and Update an Appointment. All that is left is handle the Delete.

Delete View

DeleteView is an especially handy view class. It shows users a confirmation page before deleting the specified object.

Like UpdateView, DeleteView finds the object to delete by using the pk parameter in its URL, declared in reminders/urls.py:

1from .views import AppointmentDeleteView
2
3re_path(r'^/(?P[0-9]+)/delete$', AppointmentDeleteView.as_view(), name='delete_appointment'),

We also need to specify a success_url property on our view class. This property tells Django where to send users after a successful deletion. In our case, we'll send them back to the list of appointments at the URL named list_appointments.

When a Django project starts running, it evaluates views before URLs, so we need to use the reverse_lazy utility function to get our appointment list URL instead of reverse.

By default, our AppointmentDeleteView will look for a template named appointment_confirm_delete.html. You can check out ours in the templates/reminders directory.

And that closes out this user story.

Import generic views

reminders/views.py

1from django.contrib.messages.views import SuccessMessageMixin
2from django.urls import reverse_lazy
3from django.views.generic import DetailView
4from django.views.generic.edit import CreateView
5from django.views.generic.edit import DeleteView
6from django.views.generic.edit import UpdateView
7from django.views.generic.list import ListView
8
9from .models import Appointment
10
11
12class AppointmentListView(ListView):
13    """Shows users a list of appointments"""
14
15    model = Appointment
16
17
18class AppointmentDetailView(DetailView):
19    """Shows users a single appointment"""
20
21    model = Appointment
22
23
24class AppointmentCreateView(SuccessMessageMixin, CreateView):
25    """Powers a form to create a new appointment"""
26
27    model = Appointment
28    fields = ['name', 'phone_number', 'time', 'time_zone']
29    success_message = 'Appointment successfully created.'
30
31
32class AppointmentUpdateView(SuccessMessageMixin, UpdateView):
33    """Powers a form to edit existing appointments"""
34
35    model = Appointment
36    fields = ['name', 'phone_number', 'time', 'time_zone']
37    success_message = 'Appointment successfully updated.'
38
39
40class AppointmentDeleteView(DeleteView):
41    """Prompts users to confirm deletion of an appointment"""
42
43    model = Appointment
44    success_url = reverse_lazy('list_appointments')

Our users now have everything they need to manage appointments - all that's left to implement is sending the reminders.

Sending the Reminder

As an appointment system, I want to notify a customer via SMS an arbitrary interval before a future appointment.

To satisfy this user story, we need to make our application work asynchronously - on its own independent of any individual user interaction.

One of the most popular Python library for asynchronous tasks is Dramatiq. To integrate Dramatiq with our application, we need to make a few changes:

Create a new function that sends an SMS message using information from an Appointment object
Register that function as a task with Dramatiq so it can be executed asynchronously
Run a separate Dramatiq worker process alongside our Django application to call our SMS reminder function at the right time for each appointment

If you're brand new to Dramatiq, you might want to skim its Introduction to Dramatiq page before proceeding.

Send SMS reminder task

reminders/tasks.py

1from __future__ import absolute_import
2
3import arrow
4import dramatiq
5
6from django.conf import settings
7from twilio.rest import Client
8
9from .models import Appointment
10
11
12# Uses credentials from the TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN
13# environment variables
14client = Client(settings.TWILIO_ACCOUNT_SID, settings.TWILIO_AUTH_TOKEN)
15
16
17@dramatiq.actor
18def send_sms_reminder(appointment_id):
19    """Send a reminder to a phone using Twilio SMS"""
20    # Get our appointment from the database
21    try:
22        appointment = Appointment.objects.get(pk=appointment_id)
23    except Appointment.DoesNotExist:
24        # The appointment we were trying to remind someone about
25        # has been deleted, so we don't need to do anything
26        return
27
28    appointment_time = arrow.get(appointment.time, appointment.time_zone.zone)
29    body = 'Hi {0}. You have an appointment coming up at {1}.'.format(
30        appointment.name,
31        appointment_time.format('h:mm a')
32    )
33
34    client.messages.create(
35        body=body,
36        to=appointment.phone_number,
37        from_=settings.TWILIO_NUMBER,
38    )

Next we will configure Dramatiq to work with our project.

Setting up Dramatiq

Dramatiq and Django are both big Python projects, but they can work together.

By following the instructions in the Dramatiq docs, we can include our Dramatiq settings in our Django settings modules. We can also write our Dramatiq tasks in tasks.py modules that live inside our Django apps, which keeps our project layout consistent and organized.

To use Dramatiq, you also need a separate service to be your message broker. We used Redis for this project.

The Dramatiq-specific settings in our common.py settings module is DRAMATIQ_BROKER.

If you want to see all the steps to get Django, Dramatiq, Redis, and Postgres working on your machine check out the README for this project on GitHub.

Dramatiq settings

appointments/settings/common.py

1"""
2Common Django settings for the appointments project.
3
4See the local, test, and production settings modules for the values used
5in each environment.
6
7For more information on this file, see
8https://docs.djangoproject.com/en/1.8/topics/settings/
9
10For the full list of settings and their values, see
11https://docs.djangoproject.com/en/1.8/ref/settings/
12"""
13
14import os
15
16BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
17
18# SECURITY WARNING: don't run with debug turned on in production!
19DEBUG = False
20
21# SECURITY WARNING: keep the secret key used in production secret!
22SECRET_KEY = 'not-so-secret'
23
24# Twilio API
25TWILIO_NUMBER = os.environ.get('TWILIO_NUMBER')
26TWILIO_ACCOUNT_SID = os.environ.get('TWILIO_ACCOUNT_SID')
27TWILIO_AUTH_TOKEN = os.environ.get('TWILIO_AUTH_TOKEN')
28
29DRAMATIQ_BROKER = {
30    "BROKER": "dramatiq.brokers.redis.RedisBroker",
31    "OPTIONS": {
32        "url": 'redis://localhost:6379/0',
33    },
34    "MIDDLEWARE": [
35        "dramatiq.middleware.Prometheus",
36        "dramatiq.middleware.AgeLimit",
37        "dramatiq.middleware.TimeLimit",
38        "dramatiq.middleware.Callbacks",
39        "dramatiq.middleware.Retries",
40        "django_dramatiq.middleware.AdminMiddleware",
41        "django_dramatiq.middleware.DbConnectionsMiddleware",
42    ]
43}
44
45# Reminder time: how early text messages are sent in advance of appointments
46REMINDER_TIME = 30  # minutes
47
48ALLOWED_HOSTS = []
49
50# Application definition
51
52DJANGO_APPS = (
53    'django_dramatiq',
54    'django.contrib.admin',
55    'django.contrib.auth',
56    'django.contrib.contenttypes',
57    'django.contrib.sessions',
58    'django.contrib.messages',
59    'django.contrib.staticfiles'
60)
61
62THIRD_PARTY_APPS = (
63    'bootstrap3',
64    'django_forms_bootstrap',
65    'timezone_field'
66)
67
68LOCAL_APPS = (
69    'reminders',
70)
71
72INSTALLED_APPS = DJANGO_APPS + THIRD_PARTY_APPS + LOCAL_APPS
73
74MIDDLEWARE = (
75    'django.contrib.sessions.middleware.SessionMiddleware',
76    'django.middleware.common.CommonMiddleware',
77    'django.middleware.csrf.CsrfViewMiddleware',
78    'django.contrib.auth.middleware.AuthenticationMiddleware',
79    'django.contrib.messages.middleware.MessageMiddleware',
80    'django.middleware.clickjacking.XFrameOptionsMiddleware',
81    'django.middleware.security.SecurityMiddleware',
82    'whitenoise.middleware.WhiteNoiseMiddleware',
83)
84
85ROOT_URLCONF = 'appointments.urls'
86
87TEMPLATES = [
88    {
89        'BACKEND': 'django.template.backends.django.DjangoTemplates',
90        'DIRS': ['templates/'],
91        'APP_DIRS': True,
92        'OPTIONS': {
93            'context_processors': [
94                'django.template.context_processors.debug',
95                'django.template.context_processors.request',
96                'django.contrib.auth.context_processors.auth',
97                'django.contrib.messages.context_processors.messages',
98            ],
99        },
100    },
101]
102
103CRISPY_TEMPLATE_PACK = 'bootstrap3'
104
105WSGI_APPLICATION = 'appointments.wsgi.application'
106
107
108# Database
109# https://docs.djangoproject.com/en/1.8/ref/settings/#databases
110
111DATABASES = {
112    'default': {
113        'ENGINE': 'django.db.backends.postgresql_psycopg2',
114        'NAME': 'appointment_reminders'
115    }
116}
117
118
119# Internationalization
120# https://docs.djangoproject.com/en/1.8/topics/i18n/
121
122LANGUAGE_CODE = 'en-us'
123
124TIME_ZONE = 'UTC'
125
126USE_I18N = True
127
128USE_L10N = True
129
130USE_TZ = True
131
132
133# Static files (CSS, JavaScript, Images)
134# https://docs.djangoproject.com/en/1.8/howto/static-files/
135
136STATIC_ROOT = BASE_DIR + '/staticfiles'
137
138STATIC_URL = '/static/'

Now that Dramatiq is working with our project, it's time to write a new task for sending a customer an SMS message about their appointment.

Creating a Dramatiq task

Our task takes an appointment's ID - it's primary key - as its only argument. We could pass the Appointment object itself as the argument, but this best practice ensures our SMS will use the most up-to-date version of our appointment's data.

It also gives us an opportunity to check if the appointment has been deleted before the reminder was sent, which we do at the top of our function. This way we won't send SMS reminders for appointments that don't exist anymore.

Fetch appointments on Dramatiq task

reminders/tasks.py

1from __future__ import absolute_import
2
3import arrow
4import dramatiq
5
6from django.conf import settings
7from twilio.rest import Client
8
9from .models import Appointment
10
11
12# Uses credentials from the TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN
13# environment variables
14client = Client(settings.TWILIO_ACCOUNT_SID, settings.TWILIO_AUTH_TOKEN)
15
16
17@dramatiq.actor
18def send_sms_reminder(appointment_id):
19    """Send a reminder to a phone using Twilio SMS"""
20    # Get our appointment from the database
21    try:
22        appointment = Appointment.objects.get(pk=appointment_id)
23    except Appointment.DoesNotExist:
24        # The appointment we were trying to remind someone about
25        # has been deleted, so we don't need to do anything
26        return
27
28    appointment_time = arrow.get(appointment.time, appointment.time_zone.zone)
29    body = 'Hi {0}. You have an appointment coming up at {1}.'.format(
30        appointment.name,
31        appointment_time.format('h:mm a')
32    )
33
34    client.messages.create(
35        body=body,
36        to=appointment.phone_number,
37        from_=settings.TWILIO_NUMBER,
38    )

Let's stay in our task a bit longer, because the next step is to compose the text of our SMS message.

Sending an SMS Message

We use the handy arrow library to format our appointment's time. After that, we use the twilio-python library to send our message.

We instantiate a Twilio REST client at the top of the module, which looks for TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN environment variables to authenticate itself. You can find the correct values for you in your account dashboard.

To send the SMS message itself, you'll call client.messages.create(), passing arguments for the body of the SMS message, the recipient's phone number, and the Twilio phone number you want to send this message from. Twilio will deliver the SMS message immediately.

Send SMS on Dramatiq task

reminders/tasks.py

1from __future__ import absolute_import
2
3import arrow
4import dramatiq
5
6from django.conf import settings
7from twilio.rest import Client
8
9from .models import Appointment
10
11
12# Uses credentials from the TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN
13# environment variables
14client = Client(settings.TWILIO_ACCOUNT_SID, settings.TWILIO_AUTH_TOKEN)
15
16
17@dramatiq.actor
18def send_sms_reminder(appointment_id):
19    """Send a reminder to a phone using Twilio SMS"""
20    # Get our appointment from the database
21    try:
22        appointment = Appointment.objects.get(pk=appointment_id)
23    except Appointment.DoesNotExist:
24        # The appointment we were trying to remind someone about
25        # has been deleted, so we don't need to do anything
26        return
27
28    appointment_time = arrow.get(appointment.time, appointment.time_zone.zone)
29    body = 'Hi {0}. You have an appointment coming up at {1}.'.format(
30        appointment.name,
31        appointment_time.format('h:mm a')
32    )
33
34    client.messages.create(
35        body=body,
36        to=appointment.phone_number,
37        from_=settings.TWILIO_NUMBER,
38    )

With our send_sms_reminder task complete, let's look at how to call it when our appointments are created or updated.

Calling our Reminder Task

We added a new method on our Appointment model to help schedule a reminder for an individual appointment.

Our method starts by using arrow again to build a new datetime with the appointment's time and time_zone.

Moving backward in time can be tricky in normal Python, but arrow's .replace() method lets us subtract minutes from our appointment_time. The REMINDER_TIME setting defaults to 30 minutes.

We finish by invoking our Dramatiq task, using the delay parameter to tell Dramatiq when this task should execute.

We can't import the send_sms_reminder task at the top of our models.py module because the tasks.py module imports the Appointment model. Importing it in our schedule_reminder method avoids a circular dependency.

Schedule a new Dramatiq task

reminders/models.py

1from __future__ import unicode_literals
2
3import redis
4
5from django.core.exceptions import ValidationError
6from django.conf import settings
7from django.db import models
8from django.urls import reverse
9from six import python_2_unicode_compatible
10from timezone_field import TimeZoneField
11
12import arrow
13
14
15@python_2_unicode_compatible
16class Appointment(models.Model):
17    name = models.CharField(max_length=150)
18    phone_number = models.CharField(max_length=15)
19    time = models.DateTimeField()
20    time_zone = TimeZoneField(default='UTC')
21
22    # Additional fields not visible to users
23    task_id = models.CharField(max_length=50, blank=True, editable=False)
24    created = models.DateTimeField(auto_now_add=True)
25
26    def __str__(self):
27        return 'Appointment #{0} - {1}'.format(self.pk, self.name)
28
29    def get_absolute_url(self):
30        return reverse('reminders:view_appointment', args=[str(self.id)])
31
32    def clean(self):
33        """Checks that appointments are not scheduled in the past"""
34
35        appointment_time = arrow.get(self.time, self.time_zone.zone)
36
37        if appointment_time < arrow.utcnow():
38            raise ValidationError(
39                'You cannot schedule an appointment for the past. '
40                'Please check your time and time_zone')
41
42    def schedule_reminder(self):
43        """Schedule a Dramatiq task to send a reminder for this appointment"""
44
45        # Calculate the correct time to send this reminder
46        appointment_time = arrow.get(self.time, self.time_zone.zone)
47        reminder_time = appointment_time.shift(minutes=-30)
48        now = arrow.now(self.time_zone.zone)
49        milli_to_wait = int(
50            (reminder_time - now).total_seconds()) * 1000
51
52        # Schedule the Dramatiq task
53        from .tasks import send_sms_reminder
54        result = send_sms_reminder.send_with_options(
55            args=(self.pk,),
56            delay=milli_to_wait)
57
58        return result.options['redis_message_id']
59
60    def save(self, *args, **kwargs):
61        """Custom save method which also schedules a reminder"""
62
63        # Check if we have scheduled a reminder for this appointment before
64        if self.task_id:
65            # Revoke that task in case its time has changed
66            self.cancel_task()
67
68        # Save our appointment, which populates self.pk,
69        # which is used in schedule_reminder
70        super(Appointment, self).save(*args, **kwargs)
71
72        # Schedule a new reminder task for this appointment
73        self.task_id = self.schedule_reminder()
74
75        # Save our appointment again, with the new task_id
76        super(Appointment, self).save(*args, **kwargs)
77
78    def cancel_task(self):
79        redis_client = redis.Redis(host=settings.REDIS_LOCAL, port=6379, db=0)
80        redis_client.hdel("dramatiq:default.DQ.msgs", self.task_id)

The last thing we need to do is ensure Django calls our schedule_reminder method every time an Appointment object is created or updated.

Overriding the Appointment Save Method

The best way to do that is to override our model's save method, including an extra call to schedule_reminder after the object's primary key has been assigned.

Avoiding duplicate or mistimed reminders

Scheduling a Dramatiq task every time an appointment is saved has an unfortunate side effect - our customers will receive duplicate reminders if an appointment was saved more than once. And those reminders could be sent at the wrong time if an appointment's time field was changed after its creation.

To fix this, we keep track of each appointment's reminder task through the task_id field, which stores Dramatiq's unique identifier for each task.

We then look for a previously scheduled task at the top of our custom save method and cancel it if present.

This guarantees that one and exactly one reminder will be sent for each appointment in our database, and that it will be sent at the most recent time provided for that appointment.

Overriden save() method to call schedule_reminder()

reminders/models.py

1from __future__ import unicode_literals
2
3import redis
4
5from django.core.exceptions import ValidationError
6from django.conf import settings
7from django.db import models
8from django.urls import reverse
9from six import python_2_unicode_compatible
10from timezone_field import TimeZoneField
11
12import arrow
13
14
15@python_2_unicode_compatible
16class Appointment(models.Model):
17    name = models.CharField(max_length=150)
18    phone_number = models.CharField(max_length=15)
19    time = models.DateTimeField()
20    time_zone = TimeZoneField(default='UTC')
21
22    # Additional fields not visible to users
23    task_id = models.CharField(max_length=50, blank=True, editable=False)
24    created = models.DateTimeField(auto_now_add=True)
25
26    def __str__(self):
27        return 'Appointment #{0} - {1}'.format(self.pk, self.name)
28
29    def get_absolute_url(self):
30        return reverse('reminders:view_appointment', args=[str(self.id)])
31
32    def clean(self):
33        """Checks that appointments are not scheduled in the past"""
34
35        appointment_time = arrow.get(self.time, self.time_zone.zone)
36
37        if appointment_time < arrow.utcnow():
38            raise ValidationError(
39                'You cannot schedule an appointment for the past. '
40                'Please check your time and time_zone')
41
42    def schedule_reminder(self):
43        """Schedule a Dramatiq task to send a reminder for this appointment"""
44
45        # Calculate the correct time to send this reminder
46        appointment_time = arrow.get(self.time, self.time_zone.zone)
47        reminder_time = appointment_time.shift(minutes=-30)
48        now = arrow.now(self.time_zone.zone)
49        milli_to_wait = int(
50            (reminder_time - now).total_seconds()) * 1000
51
52        # Schedule the Dramatiq task
53        from .tasks import send_sms_reminder
54        result = send_sms_reminder.send_with_options(
55            args=(self.pk,),
56            delay=milli_to_wait)
57
58        return result.options['redis_message_id']
59
60    def save(self, *args, **kwargs):
61        """Custom save method which also schedules a reminder"""
62
63        # Check if we have scheduled a reminder for this appointment before
64        if self.task_id:
65            # Revoke that task in case its time has changed
66            self.cancel_task()
67
68        # Save our appointment, which populates self.pk,
69        # which is used in schedule_reminder
70        super(Appointment, self).save(*args, **kwargs)
71
72        # Schedule a new reminder task for this appointment
73        self.task_id = self.schedule_reminder()
74
75        # Save our appointment again, with the new task_id
76        super(Appointment, self).save(*args, **kwargs)
77
78    def cancel_task(self):
79        redis_client = redis.Redis(host=settings.REDIS_LOCAL, port=6379, db=0)
80        redis_client.hdel("dramatiq:default.DQ.msgs", self.task_id)

Fun tutorial, right? Where can we take it from here?

Finishing the Django Appointment Reminder Implementation

We used Django's class-based views to help us build out the features to support CRUD operations on our Appointment model.

We then integrated Dramatiq into our project and used the twilio-python helper library to send SMS reminders about our appointments asynchronously.

You'll find instructions to run this project locally in its GitHub README.

The Appointment Model

reminders/models.py

1from __future__ import unicode_literals
2
3import redis
4
5from django.core.exceptions import ValidationError
6from django.conf import settings
7from django.db import models
8from django.urls import reverse
9from six import python_2_unicode_compatible
10from timezone_field import TimeZoneField
11
12import arrow
13
14
15@python_2_unicode_compatible
16class Appointment(models.Model):
17    name = models.CharField(max_length=150)
18    phone_number = models.CharField(max_length=15)
19    time = models.DateTimeField()
20    time_zone = TimeZoneField(default='UTC')
21
22    # Additional fields not visible to users
23    task_id = models.CharField(max_length=50, blank=True, editable=False)
24    created = models.DateTimeField(auto_now_add=True)
25
26    def __str__(self):
27        return 'Appointment #{0} - {1}'.format(self.pk, self.name)
28
29    def get_absolute_url(self):
30        return reverse('reminders:view_appointment', args=[str(self.id)])
31
32    def clean(self):
33        """Checks that appointments are not scheduled in the past"""
34
35        appointment_time = arrow.get(self.time, self.time_zone.zone)
36
37        if appointment_time < arrow.utcnow():
38            raise ValidationError(
39                'You cannot schedule an appointment for the past. '
40                'Please check your time and time_zone')
41
42    def schedule_reminder(self):
43        """Schedule a Dramatiq task to send a reminder for this appointment"""
44
45        # Calculate the correct time to send this reminder
46        appointment_time = arrow.get(self.time, self.time_zone.zone)
47        reminder_time = appointment_time.shift(minutes=-30)
48        now = arrow.now(self.time_zone.zone)
49        milli_to_wait = int(
50            (reminder_time - now).total_seconds()) * 1000
51
52        # Schedule the Dramatiq task
53        from .tasks import send_sms_reminder
54        result = send_sms_reminder.send_with_options(
55            args=(self.pk,),
56            delay=milli_to_wait)
57
58        return result.options['redis_message_id']
59
60    def save(self, *args, **kwargs):
61        """Custom save method which also schedules a reminder"""
62
63        # Check if we have scheduled a reminder for this appointment before
64        if self.task_id:
65            # Revoke that task in case its time has changed
66            self.cancel_task()
67
68        # Save our appointment, which populates self.pk,
69        # which is used in schedule_reminder
70        super(Appointment, self).save(*args, **kwargs)
71
72        # Schedule a new reminder task for this appointment
73        self.task_id = self.schedule_reminder()
74
75        # Save our appointment again, with the new task_id
76        super(Appointment, self).save(*args, **kwargs)
77
78    def cancel_task(self):
79        redis_client = redis.Redis(host=settings.REDIS_LOCAL, port=6379, db=0)
80        redis_client.hdel("dramatiq:default.DQ.msgs", self.task_id)

Where to Next?

And with a little code and a dash of configuration, we're ready to get automated appointment reminders firing in our application. Good work!

If you are a Python developer working with Twilio, you might want to check out the following resources for Python:

Browser Call: Put a button on your web page that connects visitors to live support or sales people via telephone.
Verify Python Quickstart: Verify phone numbers and add an additional layer of security to your Python app by using Twilio Verify.

Send Appointment Reminders with Python and Django

Info

Appointment Reminder Building Blocks

How To Read This Tutorial

Meet our Django Appointment Reminder Stack

Project dependencies

Creating an Appointment

The Appointment Model

Appointment model fields

New Appointment View

Create new Appointment

Wiring up the URLs

Wire up URL with create Appointment view

New Appointment Form

New Appointment form

Appointment Form Datepicker

Datepicker widget

Add a get_absolute_url() Method

get_absolute_url method

Interacting with Appointments

Interacting with appointments

Showing a List of Appointments

List appointments

Appointment List Template

Render Appointment list

Tweaking our Form Template

Tweaking new Appointment form

Delete View

Import generic views

Sending the Reminder

Send SMS reminder task

Setting up Dramatiq

Dramatiq settings

Creating a Dramatiq task

Fetch appointments on Dramatiq task

Sending an SMS Message

Send SMS on Dramatiq task

Calling our Reminder Task

Schedule a new Dramatiq task

Overriding the Appointment Save Method

Overriden save() method to call schedule_reminder()

Finishing the Django Appointment Reminder Implementation

The Appointment Model

Where to Next?