ch14

ch14/apic/apic/__init__.py

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+# apic/apic/__init__.py

ch14/apic/apic/asgi.py

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+# apic/apic/asgi.py
+"""
+ASGI config for apic project.
+
+It exposes the ASGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/3.2/howto/deployment/asgi/
+"""
+
+import os
+
+from django.core.asgi import get_asgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "apic.settings")
+
+application = get_asgi_application()

ch14/apic/apic/settings.py

@@ -0,0 +1,132 @@
+# apic/apic/settings.py
+"""
+Django settings for apic project.
+
+Generated by 'django-admin startproject' using Django 3.2.6.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/3.2/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/3.2/ref/settings/
+"""
+
+from pathlib import Path
+
+# Build paths inside the project like this: BASE_DIR / 'subdir'.
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = "django-insecure-98u5ntukr@mo0e5c*ve+8bk5$i3lr+4n4gc^@=b-7c*j_lyxa("
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    "rails.apps.RailsConfig",
+    "django.contrib.admin",
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+]
+
+MIDDLEWARE = [
+    "django.middleware.security.SecurityMiddleware",
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.middleware.common.CommonMiddleware",
+    "django.middleware.csrf.CsrfViewMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+    "django.contrib.messages.middleware.MessageMiddleware",
+    "django.middleware.clickjacking.XFrameOptionsMiddleware",
+]
+
+ROOT_URLCONF = "apic.urls"
+
+TEMPLATES = [
+    {
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "DIRS": [],
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "context_processors": [
+                "django.template.context_processors.debug",
+                "django.template.context_processors.request",
+                "django.contrib.auth.context_processors.auth",
+                "django.contrib.messages.context_processors.messages",
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = "apic.wsgi.application"
+
+
+# Database
+# https://docs.djangoproject.com/en/3.2/ref/settings/#databases
+
+DATABASES = {
+    "default": {
+        "ENGINE": "django.db.backends.sqlite3",
+        "NAME": BASE_DIR / "db.sqlite3",
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/3.2/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        "NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",
+    },
+    {
+        "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
+    },
+    {
+        "NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",
+    },
+    {
+        "NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/3.2/topics/i18n/
+
+LANGUAGE_CODE = "en-us"
+
+TIME_ZONE = "UTC"
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/3.2/howto/static-files/
+
+STATIC_URL = "/static/"
+
+# Default primary key field type
+# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
+
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+
+
+# API Settings
+
+BASE_API_URL = "http://localhost:8000"

ch14/apic/apic/urls.py

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+# apic/apic/urls.py
+"""apic URL Configuration
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/3.2/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  path('', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
+Including another URLconf
+    1. Import the include() function: from django.urls import include, path
+    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
+"""
+from django.contrib import admin
+from django.urls import include, path
+
+urlpatterns = [
+    path("", include("rails.urls")),
+    path("admin/", admin.site.urls),
+]

ch14/apic/apic/wsgi.py

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+# apic/apic/wsgi.py
+"""
+WSGI config for apic project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/3.2/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "apic.settings")
+
+application = get_wsgi_application()

ch14/apic/manage.py

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+# apic/manage.py
+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+import os
+import sys
+
+
+def main():
+    """Run administrative tasks."""
+    os.environ.setdefault(
+        "DJANGO_SETTINGS_MODULE", "apic.settings"
+    )
+    try:
+        from django.core.management import (
+            execute_from_command_line,
+        )
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == "__main__":
+    main()

ch14/apic/rails/__init__.py

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+# apic/rails/__init__.py

ch14/apic/rails/admin.py

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+# apic/rails/admin.py
+from django.contrib import admin
+
+# Register your models here.

ch14/apic/rails/apps.py

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+# apic/rails/apps.py
+from django.apps import AppConfig
+
+
+class RailsConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "rails"

ch14/apic/rails/forms.py

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+# apic/rails/forms.py
+from django import forms
+
+
+class AuthenticateForm(forms.Form):
+    email = forms.EmailField(max_length=256, label="Username")
+    password = forms.CharField(
+        label="Password", widget=forms.PasswordInput
+    )

ch14/apic/rails/migrations/__init__.py

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+# apic/rails/migrations/__init__.py

ch14/apic/rails/models.py

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+# apic/rails/models.py
+from django.db import models
+
+# Create your models here.

ch14/apic/rails/static/rails/style.css

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+body {
+  font-family: "Georgia", Times, serif;
+}
+
+.bg_color1 {
+    background-color: lightsteelblue;
+    padding: 0.1em 0 0.1em 0.8em;
+}
+
+.bg_color2 {
+    background-color:whitesmoke;
+    padding: 0.1em 0 0.1em 0.8em;
+}
+
+.footer {
+    padding-top: 1em;
+}
+
+a {
+    color: #333;
+}
+
+a:hover {
+    color:steelblue;
+}
+
+.error {
+    color:darkred;
+}

ch14/apic/rails/templates/rails/arrivals.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Arrivals{% endblock %}
+
+{% block content %}
+
+{% if arrivals %}
+    <h1>Arrivals to {{ arrivals.0.station_to.city }} ({{ arrivals.0.station_to.code }})</h1>
+{% endif %}
+
+{% for arv in arrivals %}
+
+    <div class="{% cycle 'bg_color1' 'bg_color2' %}">
+        <h3>{{ arv.name }}</h3>
+        <p>
+            <em>Departs at</em>: {{ arv.departs_at }}<br>
+            <em>Arrives at</em>: {{ arv.arrives_at }}<br>
+            <em>Cars</em>: {{ arv.first_class}} FC,
+            {{ arv.second_class }} SC
+            ({{ arv.seats_per_car }} seats/car)
+        </p>
+    </div>
+
+{% empty %}
+
+    {% if error %}
+
+        <div class=" error">
+            <h3>Error</h3>
+            <p>There was a problem connecting to the API.</p>
+            <code>{{ error }}</code>
+            <p>
+                (<em>The above error is shown to the user as an example.
+                    For security reasons these errors are normally hidden from the user</em>)
+            </p>
+        </div>
+
+    {% else %}
+
+    <div>
+        <p>There are no arrivals available at this time.</p>
+    </div>
+
+    {% endif %}
+
+{% endfor %}
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+    <a href="{% url 'stations' %}">Back to stations</a>
+</div>
+{% endblock %}

ch14/apic/rails/templates/rails/authenticate.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Authentication{% endblock %}
+
+{% block content %}
+
+    <h1>Authentication</h1>
+
+    <form action="{% url 'authenticate' %}" method="post">
+        {% csrf_token %}
+        {{ form.as_p }}
+        <input type="submit" value="Authenticate">
+    </form>
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+    <a href="{% url 'index' %}">Home</a>
+</div>
+{% endblock %}

ch14/apic/rails/templates/rails/authenticate.result.html

@@ -0,0 +1,38 @@
+{% extends "rails/base.html" %}
+
+{% block title %}Authentication Result{% endblock %}
+
+{% block content %}
+
+{% if token %}
+
+<p>
+    <label for="token">
+        <h3>Your JWT token:</h3>
+    </label>
+</p>
+
+<textarea id="token" name="token" rows="5" cols="60">
+{{ token }}
+</textarea>
+
+{% else %}
+
+<p>We were unable to retrieve your token.</p>
+
+{% if auth_error %}
+
+<code class="error">{{ auth_error }}</code>
+
+{% endif %}
+
+{% endif %}
+
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+    <a href="{% url 'authenticate' %}">Back to authenticate</a>
+</div>
+{% endblock %}

ch14/apic/rails/templates/rails/base.html

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+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="UTF-8">
+<title>{% block title %}Hello{% endblock %}</title>
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<link rel="stylesheet" type="text/css" href="{% static 'rails/style.css' %}">
+
+<body>
+    {% block content %}
+    {% endblock %}
+
+    {% block footer %}
+    {% endblock %}
+</body>
+
+</html>

ch14/apic/rails/templates/rails/departures.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Departures{% endblock %}
+
+{% block content %}
+
+{% if departures %}
+    <h1>Departures from {{ departures.0.station_from.city }} ({{ departures.0.station_from.code }})</h1>
+{% endif %}
+
+{% for dep in departures %}
+<div class="{% cycle 'bg_color1' 'bg_color2' %}">
+    <h3>{{ dep.name }}</h3>
+    <p>
+        <em>Departs at</em>: {{ dep.departs_at }}<br>
+        <em>Arrives at</em>: {{ dep.arrives_at }}<br>
+        <em>Cars</em>: {{ dep.first_class}} FC,
+        {{ dep.second_class }} SC
+        ({{ dep.seats_per_car }} seats/car)
+    </p>
+</div>
+
+{% empty %}
+
+    {% if error %}
+
+        <div class=" error">
+            <h3>Error</h3>
+            <p>There was a problem connecting to the API.</p>
+            <code>{{ error }}</code>
+            <p>
+                (<em>The above error is shown to the user as an example.
+                    For security reasons these errors are normally hidden from the user</em>)
+            </p>
+        </div>
+
+    {% else %}
+
+    <div>
+        <p>There are no departures available at this time.</p>
+    </div>
+
+    {% endif %}
+
+{% endfor %}
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+    <a href="{% url 'stations' %}">Back to stations</a>
+</div>
+{% endblock %}

ch14/apic/rails/templates/rails/index.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Home{% endblock %}
+
+{% block content %}
+
+
+<h1>Wecome to our Railways website!</h1>
+
+<p>Please choose which page you wish to visit below.</p>
+
+<p>
+    <a href="{% url 'stations' %}">Stations</a>
+</p>
+
+<p>
+    <a href="{% url 'users' %}">Users</a>
+</p>
+
+<p>
+    <a href="{% url 'authenticate' %}">Authentication</a>
+</p>
+
+{% endblock %}
+
+{% block footer %}{% endblock %}

ch14/apic/rails/templates/rails/stations.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Stations{% endblock %}
+
+{% block content %}
+
+{% if stations %}
+  <h1>Stations</h1>
+{% endif %}
+
+{% for station in stations %}
+
+  <div class="{% cycle 'bg_color1' 'bg_color2' %}">
+    <p>Id: {{ station.id }} &lt;Code: {{ station.code }}
+      ({{ station.city }}, {{ station.country }})&gt;&nbsp;
+      <a href="{% url 'departures' station.id %}">Departures</a> -
+      <a href="{% url 'arrivals' station.id %}"">Arrivals</a>
+      </p>
+  </div>
+
+{% empty %}
+
+  {% if error %}
+
+    <div class=" error">
+      <h3>Error</h3>
+      <p>There was a problem connecting to the API.</p>
+      <code>{{ error }}</code>
+      <p>
+        (<em>The above error is shown to the user as an example.
+          For security reasons these errors are normally hidden
+          from the user</em>)
+      </p>
+    </div>
+
+  {% else %}
+
+    <div>
+      <p>There are no stations available at this time.</p>
+    </div>
+
+  {% endif %}
+
+{% endfor %}
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+  <a href="{% url 'index' %}">Home</a>
+</div>
+{% endblock %}

ch14/apic/rails/templates/rails/users.html

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+{% extends "rails/base.html" %}
+
+{% block title %}Users{% endblock %}
+
+{% block content %}
+
+{% if users %}
+    <h1>Users</h1>
+{% endif %}
+
+{% for user in users %}
+
+<div class="{% cycle 'bg_color1' 'bg_color2' %}">
+    <p>Id: {{ user.id }} &lt;{{ user.full_name }}
+        (<a href="mailto: {{ user.email }})">{{ user.email }}</a>&gt;
+        {{ user.role|capfirst }}
+    </p>
+</div>
+
+{% empty %}
+
+    {% if error %}
+
+        <div class=" error">
+            <h3>Error</h3>
+            <p>There was a problem connecting to the API.</p>
+            <code>{{ error }}</code>
+            <p>
+                (<em>The above error is shown to the user as an example.
+                    For security reasons these errors are normally hidden from the user</em>)
+            </p>
+        </div>
+
+    {% else %}
+
+    <div>
+        <p>There are no users available at this time.</p>
+    </div>
+
+    {% endif %}
+
+{% endfor %}
+
+{% endblock %}
+
+{% block footer %}
+<div class="footer">
+    <a href="{% url 'index' %}">Home</a>
+</div>
+{% endblock %}

ch14/apic/rails/tests.py

@@ -0,0 +1,4 @@
+# apic/rails/tests.py
+from django.test import TestCase
+
+# Create your tests here.

ch14/apic/rails/urls.py

@@ -0,0 +1,32 @@
+# apic/rails/urls.py
+from django.urls import path
+
+from . import views
+
+urlpatterns = [
+    path("", views.IndexView.as_view(), name="index"),
+    path(
+        "stations", views.StationsView.as_view(), name="stations"
+    ),
+    path(
+        "stations/<int:station_id>/departures",
+        views.DeparturesView.as_view(),
+        name="departures",
+    ),
+    path(
+        "stations/<int:station_id>/arrivals",
+        views.ArrivalsView.as_view(),
+        name="arrivals",
+    ),
+    path("users", views.UsersView.as_view(), name="users"),
+    path(
+        "authenticate",
+        views.AuthenticateView.as_view(),
+        name="authenticate",
+    ),
+    path(
+        "authenticate/result",
+        views.AuthenticateResultView.as_view(),
+        name="auth_result",
+    ),
+]

ch14/apic/rails/views.py

@@ -0,0 +1,169 @@
+# apic/rails/views.py
+from datetime import datetime
+from operator import itemgetter
+from urllib.parse import urljoin
+
+import requests
+from django.conf import settings
+from django.urls import reverse_lazy
+from django.views import generic
+from requests.exceptions import RequestException
+
+from .forms import AuthenticateForm
+
+
+class IndexView(generic.TemplateView):
+    template_name = "rails/index.html"
+
+
+class StationsView(generic.TemplateView):
+    template_name = "rails/stations.html"
+
+    def get(self, request, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+
+        api_url = urljoin(settings.BASE_API_URL, "stations")
+
+        try:
+            response = requests.get(api_url)
+            response.raise_for_status()
+        except RequestException as err:
+            context["error"] = err
+        else:
+            context["stations"] = response.json()
+
+        return self.render_to_response(context)
+
+
+class DeparturesView(generic.TemplateView):
+    template_name = "rails/departures.html"
+
+    def get(self, request, station_id, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+
+        api_url = urljoin(
+            settings.BASE_API_URL,
+            f"stations/{station_id}/departures",
+        )
+
+        try:
+            response = requests.get(api_url)
+            response.raise_for_status()
+        except RequestException as err:
+            context["error"] = err
+        else:
+            trains = prepare_trains(response.json(), "departs_at")
+            context["departures"] = trains
+
+        return self.render_to_response(context)
+
+
+class ArrivalsView(generic.TemplateView):
+    template_name = "rails/arrivals.html"
+
+    def get(self, request, station_id, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+
+        api_url = urljoin(
+            settings.BASE_API_URL,
+            f"stations/{station_id}/arrivals",
+        )
+
+        try:
+            response = requests.get(api_url)
+            response.raise_for_status()
+        except RequestException as err:
+            context["error"] = err
+        else:
+            trains = prepare_trains(response.json(), "arrives_at")
+            context["arrivals"] = trains
+
+        return self.render_to_response(context)
+
+
+class UsersView(generic.TemplateView):
+    template_name = "rails/users.html"
+
+    def get(self, request, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+
+        api_url = urljoin(
+            settings.BASE_API_URL,
+            "users",
+        )
+
+        try:
+            response = requests.get(api_url)
+            response.raise_for_status()
+        except RequestException as err:
+            context["error"] = err
+        else:
+            context["users"] = response.json()
+
+        return self.render_to_response(context)
+
+
+class AuthenticateView(generic.FormView):
+    template_name = "rails/authenticate.html"
+    success_url = reverse_lazy("auth_result")
+    form_class = AuthenticateForm
+
+    def form_valid(self, form):
+        data = form.cleaned_data
+        self.api_authenticate(data["email"], data["password"])
+        # leave this as final instruction as it will just perform the redir.
+        return super().form_valid(form)
+
+    def api_authenticate(self, email, password):
+        api_url = urljoin(
+            settings.BASE_API_URL,
+            f"users/authenticate",
+        )
+
+        payload = {
+            "email": email,
+            "password": password,
+        }
+
+        try:
+            response = requests.post(api_url, json=payload)
+            response.raise_for_status()
+        except RequestException as err:
+            self.set_session_data("auth_error", str(err))
+        else:
+            key = "token" if response.ok else "auth_error"
+            self.set_session_data(key, response.json())
+
+    def set_session_data(self, key, data):
+        self.request.session[key] = data
+
+
+class AuthenticateResultView(generic.TemplateView):
+    template_name = "rails/authenticate.result.html"
+
+    def get(self, request, *args, **kwargs):
+        context = self.get_context_data(**kwargs)
+        context["token"] = request.session.pop("token", None)
+        context["auth_error"] = request.session.pop(
+            "auth_error", None
+        )
+        return self.render_to_response(context)
+
+
+def prepare_trains(trains: list[dict], key: str):
+    return list(
+        map(
+            parse_datetimes,
+            sorted(trains, key=itemgetter(key)),
+        )
+    )
+
+
+def parse_datetimes(train: dict):
+    train["arrives_at"] = datetime.fromisoformat(
+        train["arrives_at"]
+    )
+    train["departs_at"] = datetime.fromisoformat(
+        train["departs_at"]
+    )
+    return train