Project Name: Educational online platform

Introduction to the documentation of the project "Educational online platform":

Welcome to the documentation of the Educa project - an online education and training platform.

Educa is built on top of Django and provides powerful tools for creating and managing online courses, learning content, and learning materials. The platform also provides an opportunity for students to register, view, enroll, and take courses of their choice.

The goal of the Educa project is to create a user-friendly and scalable course management system and provide students with easy access to a variety of learning materials. Some key features of the project include:

Course Creation: Instructors can create new courses, add modules and content to teach students.
Registration and authorization: Students have the ability to register, log in and manage their accounts.
View Courses: Students can view available courses, their descriptions, materials, and modules.
Enrollment in courses: Students can enroll in the courses they are interested in and take them at a convenient time.
Online Learning: Educa provides an opportunity to study learning materials and take tests online.

This documentation contains a description of each component of the project, its functionality, usage and configuration. You will also find code examples to better understand how to use the various features of the project.

Architecture

Architecture and structure of the Educa project

The Educa project is built on top of Django, allowing you to build scalable and flexible education and learning applications. Let's take a look at the architecture and structure of the project in more detail:

1. Django: Educa uses the Django framework to develop a web application. Django provides many tools and libraries for database management, request processing, authorization, authentication, routing, and other tasks, making the project powerful and secure.

2. Modularity: The Educa project is built with modularity in mind. It consists of several applications, each of which is responsible for its own functionality. For example, the courses application is responsible for managing courses, modules, and content, while the students application is responsible for managing students and their study records. This architecture makes the project easily scalable and understandable for developers.

3. Database: Educa uses a PostgreSQL database to store data about courses, students, modules, content, and other information. PostgreSQL is a powerful relational database and provides a robust means for storing and processing data.

4. Applications: The Educa project consists of several Django applications:

courses: Responsible for managing courses, modules, content, and other course-related entities.
students: Manages students, their accounts and course interactions.
api: Provides APIs for interacting with the platform via a RESTful API.
chat: Provides chat functionality for communication between students and teachers.
media: Stores media files such as images and videos associated with courses and content.

5. Caching and Redis: Educa uses caching to improve performance and reduce database load. Redis is used as a cache, which allows you to save frequently used data and speed up access to them.

6. Front end: The Educa project uses standard Django tools to render templates and provide a user interface. CSS, JavaScript, and frameworks such as Bootstrap can be used for styling and visual design.

7. Asynchronous programming: To ensure higher responsiveness and scalability, the application uses asynchronous programming using the asyncio library for Python and the Twisted framework for processing asynchronous requests.

8. WebSocket: To implement a real-time chat between students and teachers, the project uses WebSocket using the Channels library.

Examples of using

Create and manage courses: Teachers can register in the system and create their own courses. They can add course information, upload materials, add modules and content (videos, text documents, quizzes, etc.). Courses can be organized around different topics, difficulty levels or target audiences.
Registration and training of students: Students can register on the platform and view available courses. They can enroll in courses that interest them and start learning. Each student has his own personal profile, where his courses, educational progress and achievements are displayed.
Messaging and chat with teachers: Students can exchange messages with teachers, ask questions and receive feedback. This facilitates communication and helps students to successfully complete the courses.
Live Learning: Educa uses WebSocket to implement real-time chat. This allows students and teachers to communicate and exchange ideas without delay, creating a more effective learning environment.
RESTful API for integration with other systems: The application provides an API for interacting with the platform. This allows you to integrate Educa with other systems and applications such as CRM or LMS.
Caching to improve performance: Redis is used as a cache to speed up access to frequently accessed data. This reduces the load on the database and improves the performance of the application.
Multi-User Environment: Educa provides many users with the opportunity to learn and teach. Users can join courses, communicate, share knowledge, and interact within the learning environment.
Support for various content types: Courses can contain various types of content, such as video tutorials, text materials, quizzes, and assignments. This allows teachers to provide students with a variety of learning materials.

These are just some examples of using the Educa application. With a flexible architecture and versatility, Educa can be adapted and extended to meet a variety of education and training needs.

Brief description of the main project files

1. chat/views.py:

The views.py file in the chat directory defines a Django view to display the course's chat room. Let's understand each part of this file:

from django.shortcuts import render, get_object_or_404: This block imports necessary functions from Django modules. render is used to render an HTML template, and get_object_or_404 allows you to get the object from the database or returns a 404 (Not Found) error page if the object is not found.
from django.http import HttpResponseForbidden: This block imports the HttpResponseForbidden class, which will be used to return a 403 (Forbidden) response if the user does not have access to the chat room.
from django.contrib.auth.decorators import login_required: This block imports the login_required decorator, which ensures that only authenticated users can access the view.
@login_required: This is a decorator that is applied to the course_chat_room function. It ensures that only authenticated users can access this view. If the user is not authenticated, Django will redirect them to the login page.
def course_chat_room(request, course_id):: This is the definition of the course_chat_room view function that will be called when the user accesses the URL associated with this view. It takes a request object and a course_id (course ID) as parameters.
try: and except:: This block of code tries to get the course object associated with the course_id that the user is asking to view the chat room. The request.user.courses_joined.get(id=course_id) function attempts to find a course that the user is subscribed to and has the specified course_id.
course = request.user.courses_joined.get(id=course_id): This is an assignment to the course variable of the found course object, if the user has access to that course.
except:: If the course object could not be found or a runtime error occurred, the view will return HttpResponseForbidden() with a 403 (Forbidden) code, indicating that the user is not allowed to access the chat room.
return render(request, 'chat/room.html', {'course': course}): If everything went well and the course was found, the function will return a response with a rendered chat/room.html HTML template, passing a course object to the template to further display the course information.

2. chat/urls.py:

The urls.py file in the chat directory is the URL routing file for the Django "chat" application. It defines a URL path and associates it with the corresponding view.

Let's take a look at the contents of this file:

from django.urls import path: This block imports the path function from the django.urls module, which is used to define URL paths in Django.
from . import views: This block imports the views module from the current package (directory). The code for the course_chat_room view was given in a previous post, and this module contains it.
app_name = 'chat': This sets the "chat" application namespace. This allows different applications to have different URL patterns with the same name.
urlpatterns = [...]: This is a list of URL routes that associate paths with specific views.
path('room/<int:course_id>/', views.course_chat_room, name='course_chat_room'): This is the URL route definition. The URL path is of the form 'room/<int:course_id>/' where <int:course_id> is a variable named course_id expected in the URL. <int> indicates that this value should be an integer.
- room/: This is the part of the URL that points to the path prefix.
- <int:course_id>: This is the course_id variable that will be extracted from the URL and passed as a parameter to the views.course_chat_room view.
- /: This is the slash character that ends the URL.
views.course_chat_room: This is the view that will be called when a request matches a specific URL path. In this case, when the user accesses the URL with the path "room/int:course_id/", the course_chat_room view from the views module will be called.
name='course_chat_room': This specifies the name of the route. It is used for links and redirects in templates or other parts of the code. In this case, the route will be named "course_chat_room" so that it can be identified elsewhere in the application.

3. chat/routing.py:

The routing.py file in the chat directory is the WebSocket URL routing file for Django Channels. Django Channels allows you to handle WebSocket connections that are used for real-time web applications such as chats or notifications.

Let's take a look at the contents of this file:

from django.urls import re_path: This block imports the re_path function from the django.urls module, which is used to define regular expressions in URL paths.
from . import consumers: This block imports the consumers module from the current package (directory). This module assumes that a ChatConsumer is defined that will handle WebSocket connections.
websocket_urlpatterns = [...]: This is a list of URL routes for WebSocket connections.
re_path(r'ws/chat/room/(?P<course_id>\d+)/$', consumers.ChatConsumer.as_asgi()): This is the URL route definition for the WebSocket connection. It uses a regular expression (r'ws/chat/room/(?P<course_id>\d+)/$') to match the URL path.
- ws/: This is the WebSocket path prefix.
- chat/: This is an optional part of the path that defines a group of WebSocket connections.
- room/: This is an optional part of the path that points to a specific chat room.
- (?P<course_id>\d+): This is a regular expression to extract course_id from the URL. course_id is expected to be a number (one or more digits).
- /$: This is the slash character that ends the URL.
consumers.ChatConsumer.as_asgi(): This is the WebSocket connection handler that will be called when the client establishes a WebSocket connection on the specified route. In this case, WebSocket connections will be handled by the ChatConsumer class from the consumers module. as_asgi() is used to convert the class into a format that can be used by Channels.

This routing.py file defines a WebSocket route for a chat room using Django Channels. When a client attempts to establish a WebSocket connection with a path matched by a regular expression, the WebSocket connection will be passed to the ChatConsumer handler, which will handle the real time chat for the specified chat room with the specified course_id.

4. chat/consumers.py:

The consumers.py file in the chat directory contains an implementation of an asynchronous WebSocket consumer that uses Django Channels to handle WebSocket connections. This consumer is responsible for real-time messaging in the course's chat room.

Let's take a look at the contents of this file:

import json: This block imports the json module to work with JSON data.
from channels.generic.websocket import AsyncWebsocketConsumer: This block imports the AsyncWebsocketConsumer class from the channels.generic.websocket module. AsyncWebsocketConsumer provides the base implementation of an asynchronous WebSocket consumer.
from asgiref.sync import async_to_sync: This block imports the async_to_sync function from the asgiref.sync module. It is used to convert asynchronous calls to synchronous ones.
from django.utils import timezone: This block imports the timezone module from django.utils to work with timezones.
class ChatConsumer(AsyncWebsocketConsumer):: This is the definition of the ChatConsumer class, which inherits from AsyncWebsocketConsumer. This class implements the handling of WebSocket connections for chat.
async def connect(self):: This connect() method is called when a new WebSocket connection is established. In this method:
- Gets the user who has established the connection from self.scope['user'].
- Get course_id from URL parameters in self.scope.
- A chat room group name is created self.room_group_name which will be used to group all clients into one group.
- The client is added to a chat room group with self.channel_layer.group_add().
- A WebSocket connection is accepted with self.accept().
async def disconnect(self, close_code):: This disconnect() method is called when the WebSocket connection is closed. In this method:
- The client is removed from the chat room group with self.channel_layer.group_discard().
async def receive(self, text_data):: This receive() method is called when a new message is received over a WebSocket connection. In this method:
- Received text data in JSON format.
- The message is retrieved from the received data.
- Writes the current time and date using timezone.now().
- Send a message to all clients in the chat room group using self.channel_layer.group_send().
async def chat_message(self, event):: This chat_message() method is called to send a message to all clients in the chat room group. In this method:
- Send the received event (message) to all clients in the group using self.send(text_data=json.dumps(event)).

This ChatConsumer handles WebSocket events such as connection establishment and disconnection, and real-time client-to-client messaging for the specified chat room.

5. chat/templates/chat/room.py:

The room.html file in the chat directory is an HTML template for displaying the course's chat room. It extends the base template base.html and contains blocks for adding specific content and JavaScript code.

Let's take a look at the contents of this file:

{% extends "base.html" %}: This block specifies that this template extends another template, base.html, which means that room.html will contain everything in base.html plus additional template-specific ones.
{% block title %}Chat room for "{{ course.title }}"{% endblock %}: This block defines the title of the page. The title will contain the name of the course in the chat room. course.title is supposed to be a variable that contains the title of the course.
{% block content %} ... {% endblock %}: This block defines the content of the page. This contains the HTML markup for displaying the chat room.
<div id="chat"> ... </div>: This block defines the container in which the chat messages will be displayed.
<div id="chat-input"> ... </div>: This block defines a container with an input field for sending messages.
{% block include_js %} ... {% endblock %}: This block allows you to include JavaScript code or variables that will be available on this page. Here, the course.id and request.user.username variables are converted to JSON format and will be available in the JavaScript code.
{% block domready %} ... {% endblock %}: This block contains the JavaScript code that will be executed after the DOM (Document Object Model) is loaded. This block implements the logic for establishing a WebSocket connection, exchanging messages, and displaying messages in the chat room.

In JavaScript code:
- A WebSocket connection is established using new WebSocket(url), where url specifies the address of the WebSocket server based on courseId.
- The onmessage event is responsible for handling new messages that come in via WebSocket. The received data is converted to JSON and added to the chat container div#chat.
- The date and time format for messages is defined using the Date object and the toLocaleString method.
- The onclose event is responsible for handling the closing of the WebSocket connection and printing an error message to the console.
- The input fields and the send message button (input#chat-message-input and input#chat-message-submit) are responsible for sending new messages via WebSocket.
- The keypress event listens for pressing the "Enter" key in the input field and sends a message when "Enter" is pressed. Thus, it is possible to send a message without clicking on the "Send" button.
- After the page is loaded, the input field is given focus so that the user can immediately start typing messages.

This room.html file is used to display the course's chat room page and allows interaction with the WebSocket server for real-time messaging.

6. courses/views.py:

The views.py file in the courses directory contains a set of Django views for handling course and module requests.

Let's take a look at the contents of this file:

from django.shortcuts import redirect, get_object_or_404: This block imports the redirect and get_object_or_404 functions from the django.shortcuts module. redirect is used to redirect the user to another page, and get_object_or_404 is used to get the object from the database or return a 404 error page if the object is not found.
from django.views.generic.base import TemplateResponseMixin, View: This block imports the TemplateResponseMixin and View classes from the django.views.generic.base module. TemplateResponseMixin provides functionality for displaying templates, and View is the base class for creating custom views.
from django.views.generic.list import ListView: This block imports the ListView class from the django.views.generic.list module. ListView is used to display lists of objects from the database.
from django.views.generic.edit import CreateView, UpdateView, DeleteView: This block imports the CreateView, UpdateView and DeleteView classes from the django.views.generic.edit module. These classes are used to create, update, and delete objects from the database.
from django.views.generic.detail import DetailView: This block imports the DetailView class from the django.views.generic.detail module. DetailView is used to display detailed information about an object from the database.
from django.contrib.auth.mixins import LoginRequiredMixin, PermissionRequiredMixin: This block imports the LoginRequiredMixin and PermissionRequiredMixin classes from the django.contrib.auth.mixins module. These classes are used to verify user authentication and access rights.
from django.urls import reverse_lazy: This block imports the reverse_lazy function from the django.urls module. reverse_lazy is used to retrieve a URL using named URL patterns by lazy loading URLs.
from django.forms.models import modelform_factory: This block imports the modelform_factory function from the django.forms.models module. This feature allows you to dynamically create forms based on a model.
from django.apps import apps: This block imports the apps module from django.apps. It is used to access application models.
from django.db.models import Count: This block imports the Count class from the django.db.models module. It is used to count the number of objects in database queries.
from django.core.cache import cache: This block imports the cache object from the django.core.cache module. It is used to work with the cache in order to optimize database queries.
from braces.views import CsrfExemptMixin, JsonRequestResponseMixin: This block imports the CsrfExemptMixin and JsonRequestResponseMixin classes from the braces.views module. CsrfExemptMixin allows you to disable CSRF validation for certain views, and JsonRequestResponseMixin provides functionality for processing requests and responses in JSON format.
from students.forms import CourseEnrollForm: This block imports the CourseEnrollForm form from the students application. This form is used to enroll students in courses.
from .forms import ModuleFormSet: This block imports the form ModuleFormSet from the current package courses.forms. The ModuleFormSet form allows you to work with a set of forms for course modules.
from .models import Course, Module, Content, Subject: This block imports the Course, Module, Content and Subject models from the current courses.models package. These models represent data for courses, modules, and their content.

The views.py file then defines various Views classes for handling requests and displaying data, such as:

ManageCourseListView: Display a list of courses owned by the current user.
OwnerMixin, OwnerEditMixin, OwnerCourseMixin, OwnerCourseEditMixin: Mixins that provide functionality for filtering and editing courses owned by the current user.
CourseCreateView, CourseUpdateView, CourseDeleteView: Views for creating, updating and deleting courses.
CourseModuleUpdateView: View for updating course modules.
ContentCreateUpdateView, ContentDeleteView: Views for creating, updating and deleting module content.
ModuleContentListView: Display a list of content for a specific course module.
ModuleOrderView, ContentOrderView: Views for reordering modules and content using AJAX requests.
CourseListView, CourseDetailView: Display a list of courses and course details.

These views allow you to process queries and display data for courses and their modules in your application.

7. courses/urls.py:

The urls.py file in the courses directory contains URL patterns (URL patterns) for handling requests related to courses and modules.

Let's take a look at the contents of this file:

from django.urls import path: This block imports the path function from the django.urls module. path is used to define URL routes.
from . import views: This block imports the views module from the current courses package. This means that the views defined in the views.py file will handle requests associated with those URL routes.
urlpatterns = [...]: This is a list of URL routes defined to process requests.
- path('mine/', views.ManageCourseListView.as_view(), name='manage_course_list'): Route to display the list of courses owned by the current user. It uses the ManageCourseListView view.
- path('create/', views.CourseCreateView.as_view(), name='course_create'): Path to create a new course. It uses the CourseCreateView view.
- path('<pk>/edit/', views.CourseUpdateView.as_view(), name='course_edit'): Route to edit an existing course by its id (pk). It uses the CourseUpdateView view.
- path('<pk>/delete/', views.CourseDeleteView.as_view(), name='course_delete'): Route to delete an existing course by course ID (pk). It uses the CourseDeleteView view.
- path('<pk>/module/', views.CourseModuleUpdateView.as_view(), name='course_module_update'): Route to update course modules by course id (pk). It uses the CourseModuleUpdateView view.
- path('module/<int:module_id>/content/<model_name>/create/', views.ContentCreateUpdateView.as_view(), name='module_content_create'): Path to create new module content. It uses the ContentCreateUpdateView view. module_id is the module ID and model_name is the name of the content model.
- path('module/<int:module_id>/content/<model_name>/<id>/', views.ContentCreateUpdateView.as_view(), name='module_content_update'): Route to update existing module content by content id (id). It uses the ContentCreateUpdateView view. module_id is the module identifier, model_name is the name of the content model.
- path('content/<int:id>/delete/', views.ContentDeleteView.as_view(), name='module_content_delete'): Route to delete existing module content by content id (id). It uses the ContentDeleteView view.
- path('module/<int:module_id>/', views.ModuleContentListView.as_view(), name='module_content_list'): Route to display a list of content for a specific course module by module id (module_id). It uses the ModuleContentListView view.
- path('module/order/', views.ModuleOrderView.as_view(), name='module_order'): Route for reordering course modules using AJAX requests. It uses the ModuleOrderView view.
- path('content/order/', views.ContentOrderView.as_view(), name='content_order'): Route for reordering module content using AJAX requests. It uses the ContentOrderView view.
- path('subject/<slug:subject>/', views.CourseListView.as_view(), name='course_list_subject'): Route to display a list of courses on a specific topic (subject). It uses the CourseListView view.
- path('<slug:slug>/', views.CourseDetailView.as_view(), name='course_detail'): Route to display course details by its unique identifier (slug). It uses the CourseDetailView view.

These URL routes define paths to various views that process requests to manage courses and course content in the application.

8. courses/models.py:

The models.py file in the courses directory defines the data models that are used to represent courses and their content in the application.

Let's take a look at the contents of this file:

from django.db import models: This block imports model classes from the django.db module.
from django.contrib.auth.models import User: This block imports the User model from the django.contrib.auth application. The User model is used to represent the users registered with the application.
from django.contrib.contenttypes.models import ContentType: This block imports the ContentType model from the django.contrib.contenttypes application. The ContentType model is used to represent content types, which allows different data models to be associated with the content that those models can use.
from django.contrib.contenttypes.fields import GenericForeignKey: This block imports the GenericForeignKey class from the django.contrib.contenttypes.fields application. GenericForeignKey is used to create a generic foreign key that allows you to associate objects with different models.
from django.template.loader import render_to_string: This block imports the render_to_string function from the django.template.loader module. render_to_string is used to render templates to a string.
from .fields import OrderField: This block imports the OrderField class from the current courses.fields package. OrderField is a custom model field that is used to control the order of elements.

The following data models are then defined in the models.py file:

Subject: The model represents the topic of the course. It contains the title (topic title) and slug (topic unique ID) fields.
Course: The model represents a course. It contains the fields owner (course owner), subject (course topic), title (course title), slug (course unique identifier), overview (course overview) and students (students enrolled in the course). students represents a set of relationships to the User model.
Module: The model represents the course module. It contains the fields course (course the module belongs to), title (module title), description (module description), and order (module order). order uses a custom OrderField field.
Content: The model represents the content of the module. It contains the fields module (the module to which the content belongs), content_type (the type of content), object_id (the identifier of the object associated with the content), and item (generalized external relationship to the content). content_type and item provide a generic association with different content types (eg text, video, image, file). Content types are limited by the limit_choices_to argument.
ItemBase: An abstract base model for various content types (text, file, image, video). Contains common fields such as owner (content owner), title (content title), created (creation date), and updated (update date). render is a method for rendering content using templates.
Text, File, Image, Video: Models representing different content types (text, file, image, video). Each of these models inherits from ItemBase and contains additional fields specific to its content type.

These data models define the structure and relationships between the various course items and their content in an application.

9. courses/middleware.py:

The middleware.py file in the courses directory defines a custom middleware for processing requests based on subdomains.

Let's take a look at the contents of this file:

from django.urls import reverse: This block imports the reverse function from the django.urls module. reverse is used to create URLs based on route names.
from django.shortcuts import get_object_or_404, redirect: This block imports the get_object_or_404 and redirect functions from the django.shortcuts module. get_object_or_404 is used to get an object from the database or return a 404 error if the object is not found. redirect is used to perform a redirect to another page.
from .models import Course: This block imports the Course model from the current courses package. The Course model represents the courses in the application.

The subdomain_course_middleware(get_response) function defines a custom middleware. This middleware does the following:

Extracts the host parts from the request (request.get_host()), separates them and checks if the host is a subdomain (has more than two parts and the first part is not equal to "www").
If the host is a subdomain, look up the course in the database with get_object_or_404 by its unique identifier (slug), which is retrieved from the first part of the host.
Then creates a URL for the course_detail view using the reverse function, using the course's unique id (slug) as an argument.
Generates a new URL based on the request scheme (request.scheme), the host parts (excluding the first subdomain part), and the generated course URL. This URL redirects the user to the course page of the subdomain.
If the host is not a subdomain, the middleware continues executing the rest of the middleware and views using get_response(request).
The response that was generated by the previous middleware or view is returned.

This middleware is supposed to be an intermediary between incoming requests and views (views), which will process requests based on subdomains and perform appropriate actions for courses on each subdomain.

10. courses/forms.py:

The forms.py file in the courses directory defines the form for the course module and creates an inline formset for the modules that can be used in course forms.

Let's take a look at the contents of this file:

from django import forms: This block imports the form classes from the django.forms module.
from django.forms.models import inlineformset_factory: This block imports the inlineformset_factory function from the django.forms.models module. inlineformset_factory is used to create an inline formset for related models.
from .models import Course, Module: This block imports the Course and Module models from the current courses package. These models represent the courses and course modules in the application.

Course module form:

The file does not contain an explicitly defined form for the course module. Instead, an inlineformset_factory is used to automatically create a module form that allows changes to be made to the Module model in the context of the Course model.

Inline formset for modules:

ModuleFormSet = inlineformset_factory(Course, Module, fields=['title', 'description'], extra=2, can_delete=True)

This block defines an inline formset for the Module models associated with the Course model. An inline formset is a set of forms associated with a Module that can be rendered and processed in the context of a Course model.

inlineformset_factory arguments:

Course: The model to which the formset belongs. In this case, it is the Course model.
Module: The model for which the formset is created. In this case, it is the Module model.
fields: Fields of the Module model that will be displayed in the form. The title and description fields are specified here.
extra: The number of extra forms that will be displayed for adding new entries. In this case, these are 2 additional forms.
can_delete: Specifies whether checkboxes for deleting existing entries will be displayed. This is set to True so the checkboxes will be displayed.

Thus, the ModuleFormSet form represents an inline formset for Module models that can be used to edit, add, and remove modules in the context of a particular Course.

11. courses/fields.py:

The fields.py file in the courses directory defines a custom model field named OrderField that is used to control the order of elements in the database.

Let's take a look at the contents of this file:

from django.db import models: This block imports the models class from the django.db module.
from django.core.exceptions import ObjectDoesNotExist: This block imports the ObjectDoesNotExist exception from the django.core.exceptions module. ObjectDoesNotExist is used to handle situations where the requested object does not exist in the database.

Class OrderField(models.PositiveIntegerField):

OrderField is a custom model field that inherits from models.PositiveIntegerField. It determines the order of the elements in the database based on their value in the given field.

Method __init__(self, for_fields=None, *args, **kwargs):

for_fields: A list of fields that will be used to determine the order of elements. If set, the order will be respected only for elements that have the same value in these fields.
*args, **kwargs: Arguments passed to the constructor of the parent class models.PositiveIntegerField.

Method pre_save(self, model_instance, add):

This method overrides the pre_save method of the base field models.PositiveIntegerField. It does the following:

If the value of the field is not defined (equal to None), then the field has not yet been stored in the database.
Next, the method tries to get the last item in the database using the latest(self.attname) method of the model class. The value of self.attname represents the name of the field for which OrderField is defined.
If the elements exist and they have the same values in the for_fields fields (if they are set), then the new order value will be one greater than the last element's order value.
If the elements do not exist or the field does not have a for_fields value, then the new order value will be 0 (the initial value).
The method then assigns the resulting order value (value) to the model attribute corresponding to self.attname (the name of the OrderField field).
If the field value is already defined (not equal to None), the method calls the parent pre_save method to perform standard save operations.

Thus, the custom field OrderField automatically assigns a unique order value to model elements when they are saved to the database, which provides control over the order of the elements.

12. courses/admin.py:

The admin.py file from the courses directory defines the settings for the administrative interface (admin panel) for the Subject, Course and Module models.

Let's take a look at the contents of this file:

from django.contrib import admin: This block imports the admin module from the django.contrib package, which contains classes and functions for customizing the Django admin interface.
from .models import Subject, Course, Module: This block imports the Subject, Course and Module models from the current courses package. These models represent the subjects, courses, and course modules in the application.

Administrative interface settings for the Subject model:

@admin.register(Subject): This decorator registers the Subject model in the admin interface so that it can be edited and viewed in the admin panel.
class SubjectAdmin(admin.ModelAdmin): This class defines the administrative interface settings for the Subject model.
list_display: List of model fields that will be displayed in the list of model objects in the admin panel.
prepopulated_fields: A dictionary that specifies which field will be auto-populated based on the value of another field. In this case, the slug field will be automatically populated based on the value of the title field.

Administrative interface settings for the Course model:

class ModuleInline(admin.StackedInline): This class defines an inline (stacked) interface for the Module model. The inline interface allows you to edit the Module model directly on the course editing page (Course).
model = Module: Specifies that the inline interface will be associated with the Module model.
inlines = [ModuleInline]: This inlines attribute adds the ModuleInline inline interface to the Course model. Now the course editing page will also display forms for editing modules associated with this course.
The rest of the CourseAdmin parameters define the admin interface settings for the Course model, including list_display (displayed fields in the list), list_filter (filters on the list page), search_fields (search fields) and prepopulated_fields (autocomplete slug based on title). This allows administrators to manage courses in the admin panel.

Thus, this admin.py provides admin interface settings for the Subject, Course and Module models, which allows administrators to manage these models in the Django admin panel.

13. courses/api/views.py:

The views.py file in the courses/api directory defines the views API for working with the Subject and Course models using the Django REST framework.

Let's take a look at the contents of this file:

from django.shortcuts import get_object_or_404: This block imports the get_object_or_404 function from the django.shortcuts module. It is used to get an object from the database according to given conditions, and if the object is missing, it throws an Http404 exception.
from rest_framework.views import APIView: This block imports the APIView class from the rest_framework.views module. APIView is the base class for creating custom API views (views) using the Django REST framework.
from rest_framework import viewsets: This block imports the viewsets class from the rest_framework module. viewsets provide a set of views (views) to handle various HTTP methods and model actions.
from rest_framework.response import Response: This block imports the Response class from the rest_framework.response module. Response is used to return data in JSON or XML format.
from rest_framework import generics: This block imports the generics classes from the rest_framework module. generics provide ready-made views for working with models, such as ListAPIView and RetrieveAPIView, which support read (GET) operations.
from rest_framework.authentication import BasicAuthentication: This block imports the BasicAuthentication class from the rest_framework.authentication module. BasicAuthentication provides user authentication with a basic HTTP authentication header.
from rest_framework.permissions import IsAuthenticated: This block imports the IsAuthenticated class from the rest_framework.permissions module. IsAuthenticated checks if the current user is authenticated.
from rest_framework.decorators import action: This block imports the action decorator from the rest_framework.decorators module. action is used to define custom actions in viewsets.
from courses.models import Subject, Course: This block imports the Subject and Course models from the courses application.
from courses.api.serializers import SubjectSerializer, CourseSerializer: This block imports the SubjectSerializer and CourseSerializer serializers from the courses.api.serializers module. Serializers convert model objects to JSON or XML formats and vice versa.
from courses.api.permissions import IsEnrolled: This block imports the IsEnrolled class from the courses.api.permissions module. IsEnrolled is a user permission that checks if the user is an enrolled course participant.

Class SubjectListView(generics.ListAPIView):

queryset = Subject.objects.all(): Query to get all objects of the Subject model.
serializer_class = SubjectSerializer: Specifies which serializer will be used to convert the Subject model data to JSON or XML format.

Class SubjectDetailView(generics.RetrieveAPIView):

queryset = Subject.objects.all(): Query to get all objects of the Subject model.
serializer_class = SubjectSerializer: Specifies which serializer will be used to convert the Subject model data to JSON or XML format.

Class CourseViewSet(viewsets.ReadOnlyModelViewSet):

queryset = Course.objects.all(): Query to get all objects of the Course model.
serializer_class = CourseSerializer: Specifies which serializer will be used to convert the Course model data to JSON or XML format.

The enroll and contents methods are custom actions (actions) and use the @action decorator:

enroll: A POST request that allows the user to register for the course.
contents: GET request that returns course content for registered participants.

Each method uses different permissions (IsAuthenticated, IsEnrolled) and authentication (BasicAuthentication) to secure data access.

14. courses/api/urls.py:

The urls.py file in the courses/api directory defines the URL routes for the views API using the Django REST framework.

Let's take a look at the contents of this file:

from django.urls import path, include: This block imports the path and include functions from the django.urls module. path is used to define URL routes, and include is used to include other URL routes from other urls.py files.
from rest_framework import routers: This block imports the routers class from the rest_framework module. routers provide automatic generation of URL routes based on viewsets.
from . import views: This block imports views from the current views.py module.
app_name = 'courses': Specifies the namespace of the application.
router = routers.DefaultRouter(): Creates a DefaultRouter object that will be used to automatically generate URL routes based on the CourseViewSet.
router.register('courses', views.CourseViewSet): Registers a CourseViewSet with router and automatically generates URL routes for it.
urlpatterns: This is a list of URL routes for API views.
- path('subjects/', views.SubjectListView.as_view(), name='subject_list'): URL route to view the list of subjects. When this URL is accessed, the SubjectListView view will be called, which displays a list of all subjects.
- path('subjects/<pk>/', views.SubjectDetailView.as_view(), name='subject_detail'): URL route to view the details of a particular subject by its pk (Primary Key). When this URL is accessed, the SubjectDetailView view will be called, which displays the details of the subject with the corresponding pk.
- path('', include(router.urls)): Includes URL routes from router, i.e. all automatically generated URL routes for CourseViewSet. They will start with an empty string, since 'courses' has been registered as the URL prefix for the CourseViewSet views. For example, courses/, courses/<pk>/, etc.

With DefaultRouter, you don't need to explicitly define URL routes for every method in CourseViewSet. Instead, DefaultRouter automatically generates URL routes for all methods that are supported in CourseViewSet such as list, retrieve, create, update, destroy and additional custom actions enroll and contents.

15. courses/api/serializers.py:

The serializers.py file in the courses/api directory defines the serializers for the Subject, Course, Module and Content models, which are used to convert model objects to and from JSON formats when working with the Django REST framework .

Let's take a look at the contents of this file:

from rest_framework import serializers: This block imports classes for creating serializers from the Django REST framework.
from courses.models import Subject, Course, Module, Content: This block imports the models that will be serialized.
class SubjectSerializer(serializers.ModelSerializer): This class defines a serializer for the Subject model. The ModelSerializer can be used to define the fields that will be serialized for the Subject model.
class ModuleSerializer(serializers.ModelSerializer): This class defines a serializer for the Module model.
class CourseSerializer(serializers.ModelSerializer): This class defines a serializer for the Course model. It also includes related serializers such as ModuleSerializer to serialize related Module objects of the Course model.
class ItemRelatedField(serializers.RelatedField): This class defines a special serializer field for related Content model objects. In this case, it is used for related ItemBase objects of the Content model.
class ContentSerializer(serializers.ModelSerializer): This class defines a serializer for the Content model. Includes ItemRelatedField to serialize related ItemBase objects of the Content model.
class ModuleWithContentsSerializer(serializers.ModelSerializer): This class defines a serializer for the Module model, including contents. Enables ContentSerializer to serialize related Content objects of the Module model.
class CourseWithContentsSerializer(serializers.ModelSerializer): This class defines a serializer for the Course model, including content (modules). Enables ModuleWithContentsSerializer to serialize related Module objects of the Course model.

Serializers allow you to convert model data to and from JSON when making API requests. They define the fields that must be represented in JSON format when serializing data and vice versa.

16. courses/api/permissions.py:

The permissions.py file in the courses/api directory defines a custom permission called IsEnrolled.

Let's take a look at the contents of this file:

from rest_framework.permissions import BasePermission: This block imports the base permission class from the Django REST framework.
class IsEnrolled(BasePermission): This class defines a custom IsEnrolled permission that allows you to check if the current user is a student of a particular course.
def has_object_permission(self, request, view, obj): This method defines the permission checking logic. In this case, it checks if the current user is a student of the specified course object (obj). The method returns True if the current user is a student of this course, False otherwise.

When the IsEnrolled permission is used on a view, it will be called on every request to course objects to determine if the current user is authorized to access that course (for example, to view course content or perform certain actions). If the has_object_permission method returns True then access is allowed, otherwise access is denied.

17. students/views.py:

The views.py file in the students directory defines views for working with students and courses in the application.

Let's take a look at the contents of this file:

from django.urls import reverse_lazy: This block imports the function for reverse URL resolution from Django.
from django.views.generic.edit import CreateView: This block imports the view class to create objects.
from django.contrib.auth.forms import UserCreationForm: This block imports the user registration form from Django.
from django.contrib.auth import authenticate, login: This block imports functions for user authentication and login.
from django.views.generic.edit import FormView: This block imports the view class to display the form.
from django.views.generic.list import ListView: This block imports a view class to display a list of objects.
from django.views.generic.detail import DetailView: This block imports a view class to display the details of an object.
from django.contrib.auth.mixins import LoginRequiredMixin: This block imports the mixin class to require user authentication.
from courses.models import Course: This block imports the Course model from the courses application.
from .forms import CourseEnrollForm: This block imports the user form CourseEnrollForm from the current students application.

The file contains the following views:

StudentRegistrationView: View class for student registration. It uses CreateView and UserCreationForm to display the registration form and create a new user.
StudentEnrollCourseView: The view class for enrolling a student in a course. It uses a FormView and a custom form CourseEnrollForm to display the form and add the student to the selected course.
StudentCourseListView: A view class for displaying a list of courses for which the current student is enrolled. Uses ListView to display a list of courses.
StudentCourseDetailView: View class for displaying course details. Uses the DetailView to display information about the selected course, and also uses the optional module_id parameter to display the selected course module, if specified.

18. students/urls.py:

The urls.py file in the students directory defines the routes (URLs) for the views in this application.

Let's take a look at the contents of this file:

from django.urls import path: This block imports the path function to define URL routes.
from django.views.decorators.cache import cache_page: This block imports the cache_page decorator, which is used to cache view output.
from . import views: This block imports all views from the current students application.

The file contains the following routes:

/register/: This route is associated with the StudentRegistrationView for student registration. When the user visits this URL, the registration form will be displayed.
/enroll-course/: This route is associated with the StudentEnrollCourseView to enroll a student in a course. When a user visits this URL, a form will be displayed to select and enroll in a course.
/courses/: This route is associated with a StudentCourseListView to display a list of courses the current student is enrolled in.
/course/<pk>/: This route is associated with the StudentCourseDetailView to display the details of the selected course with id <pk>. The output of the view will be cached for 15 minutes using the cache_page(60 * 15) decorator.
/course/<pk>/<module_id>/: This route is also associated with the StudentCourseDetailView, but it additionally takes a <module_id> parameter that points to the selected course module. The output of the view will also be cached for 15 minutes using the cache_page(60 * 15) decorator.

19. students/forms.py:

The forms.py file in the students directory contains the definition of the CourseEnrollForm form.

Let's take a look at the contents of this file:

from django import forms: This block imports the forms module from Django to define forms.
from courses.models import Course: This block imports the Course model from the courses application. This is necessary to set the queryset for course in the form CourseEnrollForm.

The CourseEnrollForm class defines the form that is used to enroll a student in a course. The form contains a single course field, which represents the course selection from the Course model.

Form fields: - course: A ModelChoiceField that uses all available courses from the Course model as a queryset. It is displayed as a hidden field (HiddenInput), which means that the user will not see it when the form is displayed, but it will be used to pass the selected course to the server when the form is submitted.

This form class is not directly associated with the model and does not store data on the server. Instead, it provides a convenient way to select a course when a student enrolls in it.

20. students/management/commands/enroll_reminder.py:

The enroll_reminder.py file in the students/management/commands directory is a custom Django command that sends an email reminder to users who have been registered for more than N days but not enrolled in courses.

Let's take a look at the contents of this file:

import datetime: This block imports the datetime module to work with dates and times.
from django.conf import settings: This block imports Django settings to access configuration options such as DEFAULT_FROM_EMAIL.
from django.core.management.base import BaseCommand: This block imports the base Django command class, BaseCommand, which is used to define custom commands.
from django.core.mail import send_mass_mail: This block imports the send_mass_mail function, which is used to send bulk emails.
from django.contrib.auth.models import User: This block imports the User model, which is used to get users.
from django.db.models import Count: This block imports the Count function, which is used to aggregate and count related objects.
from django.utils import timezone: This block imports the timezone module from Django to work with timezones.

The Command class defines a custom command named enroll_reminder. This command sends a reminder to users who have been registered for more than N days but not enrolled in courses. The command takes a --days argument that specifies the number of days, and provides a default value of 0 if no argument is given.

The handle method is the main command method that performs the main logic for sending reminders. It does the following:

Gets all users who are not enrolled in courses and registered up to N days ago.
Creates messages for each user with a reminder to enroll in courses.
Sends bulk emails with messages to users.
Displays the number of sent reminders in the console.

This command can be run from the Django command line with the command python manage.py enroll_reminder --days N, where N is the number of days to send reminders for.

21. educa/urls.py:

The urls.py file in the educa directory defines the URL patterns for the Django application.

Let's take a look at the contents of this file:

from django.contrib import admin: This block imports the admin module to enable the Django admin panel.
from django.urls import path, include: This block imports the path and include functions from the django.urls module. They are used to define URL patterns and include other URL patterns from other applications.
from django.conf import settings: This block imports the settings object from Django, which allows you to access project settings.
from django.conf.urls.static import static: This block imports the static function, which is used to serve media files during development.
from django.contrib.auth import views as auth_views: This block imports Django's authentication views.
from courses.views import CourseListView: This block imports the CourseListView view from the courses application.

URL patterns are defined in the urlpatterns list. Each URL pattern is a call to the path function, which takes a URL path and a corresponding representation. The view can be a view function or a view class.

path('accounts/login/', auth_views.LoginView.as_view(), name='login'): URL template for login. Uses the view auth_views.LoginView.as_view() to handle login.
path('accounts/logout/', auth_views.LogoutView.as_view(), name='logout'): URL template for logout. Uses the view auth_views.LogoutView.as_view() to handle logout.
path('admin/', admin.site.urls): URL template for the Django admin panel.
path('course/', include('courses.urls')): URL pattern to include URL patterns from the courses application.
path('', CourseListView.as_view(), name='course_list'): URL template for course list. Uses the CourseListView view to display a list of courses.
path('students/', include('students.urls')): URL pattern to include URL patterns from the students application.
path('api/', include('courses.api.urls', namespace='api')): URL pattern to include API URL patterns from the courses.api application.
path('chat/', include('chat.urls', namespace='chat')): URL pattern to include URL patterns from the chat application.
path('__debug__/', include('debug_toolbar.urls')) : URL template to include Django debug bar URL templates.

If settings.DEBUG is True then an additional URL pattern is added to urlpatterns to serve media files during development.

The general meaning of this file is to define the main URL patterns for various parts of the application, such as authentication, admin panel, course list, API, and others.

22. educa/asgi.py:

The asgi.py file in Django is the entry point for the ASGI (Asynchronous Server Gateway Interface) server. ASGI is an interface used to handle asynchronous requests such as websockets and other non-HTTP protocols.

Let's take a look at the contents of this file:

ASGI config for educa project.: A comment describing the purpose of the file.
import os: Imports the os module, which provides functionality for interacting with the operating system.
from django.core.asgi import get_asgi_application: Imports the get_asgi_application function from the django.core.asgi module, which creates an ASGI application to process HTTP requests.
from channels.routing import ProtocolTypeRouter, URLRouter: Imports the ProtocolTypeRouter and URLRouter classes from the channels.routing module. ProtocolTypeRouter is used to route various protocols, and URLRouter is used to route URL patterns.
from channels.security.websocket import AllowedHostsOriginValidator: Imports the AllowedHostsOriginValidator class, which checks the origin of WebSocket requests and enforces security.
from channels.auth import AuthMiddlewareStack: Imports the AuthMiddlewareStack class, which provides an authentication mechanism for WebSocket requests.
import chat.routing: Imports the chat.routing module, which contains URL patterns for WebSocket requests from the chat application.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'educa.settings'): Sets the environment variable DJANGO_SETTINGS_MODULE to educa.settings, indicating which file contains the Django project settings.
django_asgi_app = get_asgi_application(): Creates an ASGI application to process HTTP requests using the get_asgi_application() function.
application = ProtocolTypeRouter({...}): Creates an ASGI master application that routes requests to the appropriate ASGI application based on the protocol type. In this case, it handles HTTP requests using django_asgi_app and WebSocket requests are routed through AuthMiddlewareStack(URLRouter(chat.routing.websocket_urlpatterns)).

The general meaning of this file is to create an ASGI application and route HTTP and WebSocket requests to the appropriate views in the chat application in order to process websockets. This file is required to work with asynchronous requests such as websockets in a Django application.

23. educa/settings/prod.py:

The prod.py file in the educa/settings directory represents the settings for the production environment (working environment) of the Educa project. This file defines various options and settings to ensure security and performance in a production environment.

Let's take a look at the contents of this file:

import os: Imports the os module, which provides functionality for interacting with the operating system.
from .base import *: Imports all settings from the base.py file, which is the base settings file for the Educa project. The base.py file contains general settings that can be overridden or added to in this file.
DEBUG = False: Disables debug mode. In a production environment, it is recommended to disable debug mode for security and performance reasons.
ADMINS: List of project administrators with their names and email addresses. Administrators receive error notifications via email.
ALLOWED_HOSTS: A list of allowed hosts (domains) that can access the project. In this case, all subdomains of the educaproject.com site are allowed.
DATABASES: Database settings. In this case, a PostgreSQL database is used. The database name, user and password are taken from the environment variables set in the system.
REDIS_URL: URL for Redis used as a cache for the application.
CACHES: Settings for cache. In this case, Redis is used as a cache.
CHANNEL_LAYERS: Settings for working with asynchronous channels (for example, for WebSocket connections). This specifies the use of Redis as the backend for the channels.
CSRF_COOKIE_SECURE, SESSION_COOKIE_SECURE, SECURE_SSL_REDIRECT: Setting these options to True ensures that a secure connection using SSL (HTTPS) is used to protect cookies, sessions, and protect against cross-site request forgery (CSRF).

The general meaning of this file is to set up the production environment of the Educa project, taking into account the security, performance and optimal use of resources in the production environment.

24. educa/settings//local.py:

The local.py file in the educa/settings directory represents the settings for local development of the Educa project. This file defines various options and settings to make it easy and fast to develop on a local machine.

Let's take a look at the contents of this file:

from .base import *: Imports all settings from the base.py file, which is the base settings file for the Educa project. The base.py file contains general settings that can be overridden or added to in this file.
DEBUG = True: Enables debug mode. In local development, it is recommended to enable debug mode for convenience and speed of fixing errors.
DATABASES: Database settings. In this case, a SQLite database is used for local development. The database file db.sqlite3 is located in the same directory as the manage.py file, and the path to the file is formed using the BASE_DIR variable, which points to the root directory of the project.

The general meaning of this file is to set up the local development of the Educa project for convenience, debugging and using a SQLite database for local storage of data during development. Unlike the prod.py file, this file is optimized for running on the developer's local machine and is not meant to be used in a production environment.

25. educa/settings/base.py:

The base.py file in the educa/settings directory represents the base settings for the Educa project. This file defines the main parameters and configurations necessary for the project to work, but some of them can be overridden or supplemented in the local.py and prod.py files for local development and production environments, respectively.

Let's take a look at the contents of this file:

BASE_DIR: This is the path to the project's root directory. It is defined using pathlib.Path pointing one level above the current directory (three times .parent) to get the project's root directory.
SECRET_KEY: The secret key used for hashing and security in Django. In this case, this value is not safe to use in a production environment, as it is explicitly defined in the file. In a production environment, for security reasons, it is recommended to store the private key in an environment variable or some other safe place.
DEBUG = True: Enables debug mode. In the basic settings, debug mode is enabled, which allows you to receive detailed error messages during development.
ALLOWED_HOSTS = []: List of hosts that can process requests to the application. In the basic settings, this list is empty, which means that the application will process requests from any hosts. In a production environment, you must specify the specific hosts that should process requests.
INSTALLED_APPS: List of installed Django applications. Includes standard applications such as admin, auth, contenttypes, sessions, messages, staticfiles as well as custom applications courses and students, as well as various third-party applications such as embed_video, debug_toolbar, rest_framework, chat, channels.
MIDDLEWARE: A list of middleware that handles requests and responses before they enter the view handlers and after they exit the view handlers. Some middleware such as SecurityMiddleware, SessionMiddleware, AuthenticationMiddleware, MessageMiddleware are enabled by default.
TEMPLATES: Configuration of templates for the project. Defined settings for DjangoTemplates with the APP_DIRS=True parameter so that templates are looked up in application directories.
WSGI_APPLICATION: Path to the WSGI application module to use in the web server. In this case, educa.wsgi.application is used.
STATIC_URL and STATIC_ROOT: URL and root directory for static files (CSS, JavaScript, images, etc.).
MEDIA_URL and MEDIA_ROOT: URL and root directory for media files (user uploaded files).
CACHE_*: Settings for caching. The basic settings use RedisCache for session caching.
INTERNAL_IPS: List of internal IP addresses that can access the debug toolbar during development.
REST_FRAMEWORK: Settings for the RESTful API framework.
ASGI_APPLICATION and CHANNEL_LAYERS: Settings for working with WebSocket and asynchronous processing with Channels.
EMAIL_BACKEND: Type of backend for sending email. The basic settings use EmailBackend, which prints email to the console instead of actually sending it. In a production environment, you should use a different backend to actually send email.

26. docker-compose.yml

The docker-compose.yml file contains the description of the services that will be started by Docker Compose for the project. Each service represents a separate container that will work alongside other containers.

Let's break down each section:

The cache section: This service runs a version 7.0.4 Redis container. Redis is used in this case for data caching. The container will always be restarted (restart: always parameter) and will be connected to the ./data/cache directory where the Redis data will be stored.
db section: This service starts a PostgreSQL version 14.5 container. PostgreSQL is used in this case to store project database data. The container will always restart and will be connected to the ./data/db directory where the PostgreSQL data will be stored. Environment variables for setting up the database are also defined, such as the database name, username, and password.
web section: This service runs a container for a Django application. It will be built from the current directory (., means current project directory) using a Dockerfile. The container will be started using the command ./wait-for-it.sh db:5432 -- uwsgi --ini /code/config/uwsgi/uwsgi.ini which waits for the PostgreSQL database container to be available and then starts uWSGI to processing web requests. The container will always restart and will be connected to the . directory where the project code is located. Environment variables are also defined to configure the Django application and database, such as the database name, username, and password.
daphne section: This service runs a container for WebSocket and asynchronous processing with Daphne. The container will be built from the current directory (., means the current project directory) using the Dockerfile. The container will be started using the command ../wait-for-it.sh db:5432 -- daphne -u /code/educa/daphne.sock educa.asgi:application which waits for the PostgreSQL database container to be available and then starts Daphne to handle WebSocket connections. The container will always restart and will be connected to the . directory where the project code is located. Environment variables are also defined to configure the Django application and database, such as the database name, username, and password.
nginx section: This service runs a container for the Nginx web server version 1.23.1. Nginx is used in this case to process web requests, proxy requests to a Django application, and process requests over HTTP and HTTPS. The container will always restart and will be connected to the ./config/nginx directory where the Nginx configuration files are stored. Also, the container will be connected to the current directory ., where the project code is located. Ports 80 and 443 are also defined, through which HTTP and HTTPS will be available, respectively.

Please note that the docker-compose.yml file is for running a project in Docker using Docker Compose, and uses a combination of various containers such as a database, a Redis cache, a Django application, Nginx and Daphne to provide a full web experience. applications.

27. Dockerfile

This Dockerfile is the Docker configuration file that is used to create the Docker image for your Django application. It describes how to build a container, including installing Python, installing dependencies, and copying the application code.

Here is what each line in the Dockerfile does:

FROM python:3.11.0: Specifies the base image from which the container will be created. In this case, the official Python image is version 3.11.0.
ENV PYTHONDONTWRITEBYTECODE=1: Sets the PYTHONDONTWRITEBYTECODE environment variable, which prevents the creation of .pyc files (compiled Python files).
ENV PYTHONUNBUFFERED=1: Sets the PYTHONUNBUFFERED environment variable, which disables Python output buffering.
WORKDIR /code: Specifies the working directory of the container where commands will be executed.
RUN pip install --upgrade pip: Upgrades the installed pip package manager to the latest version.
COPY requirements.txt /code/: Copies the requirements.txt file from the local project directory inside the container to the /code/ directory.
RUN pip install -r requirements.txt: Installs the dependencies specified in the requirements.txt file inside the container.
COPY . /code/: Copies all files and directories from the local project directory inside the container to the /code/` directory.

So the given Dockerfile takes the following steps:

Uses Python image version 3.11.0.
Sets the necessary environment variables.
Copies the requirements.txt file and installs the dependencies.
Copies all files and directories from the local project directory to the container.

As a result of executing this Dockerfile, you will get a Docker image that contains your Django application inside a container.

28. requirements.txt

The requirements.txt file contains a list of all Python dependencies (packages) that need to be installed for your project to work properly. These dependencies will be installed when building the Docker image when pip install -r requirements.txt is executed.

In this case, the requirements.txt file contains the following dependencies with the specified versions:

aioredis==1.3.1
asgiref==3.7.2
async-timeout==4.0.2
attrs==23.1.0
autobahn==23.6.2
Automat==22.10.0
certifi==2023.7.22
cffi==1.15.1
channels==3.0.5
channels-redis==3.4.1
charset-normalizer==2.1.1
constantly==15.1.0
cryptography==41.0.2
daphne==3.0.2
Deprecated==1.2.14
Django==4.1.10
django-braces==1.15.0
django-debug-toolbar==3.6.0
django-embed-video==1.4.4
django-redisboard==8.3.0
djangorestframework==3.13.1
hiredis==2.2.3
hyperlink==21.0.0
idna==3.4
incremental==22.10.0
msgpack==1.0.5
packaging==23.1
Pillow==9.2.0
psycopg2==2.9.3
pyasn1==0.5.0
pyasn1-modules==0.3.0
pycparser==2.21
pymemcache==3.5.2
pyOpenSSL==23.2.0
pytz==2023.3
redis==4.3.4
requests==2.28.1
service-identity==23.1.0
six==1.16.0
sqlparse==0.4.4
Twisted==22.10.0
txaio==23.1.1
typing_extensions==4.7.1
urllib3==1.26.16
wrapt==1.15.0
zope.interface==6.0

These dependencies include various libraries and packages needed to work with Django, Channels, Redis, PostgreSQL, and other third party libraries that have been installed in the project.

29. wait-for-it.sh

The wait-for-it.sh file is a bash script that is used to check if a given TCP host and port is available before starting another process. It is widely used in Docker container environments and other microservice architectures to wait for a service or database to be ready before starting other parts of the application.

The main functions and features of this script:

Check host and port availability with nc command (or /dev/tcp if nc is not available).
Ability to set a timeout to wait for host and port availability.
Support for displaying status information (for example, "Waiting for host:port ...").
Ability to run another command after a successful wait (for example, launching an application).
Support for strict mode, in which the application launch process will be rejected if the host and port are unavailable.
Checking for the presence of the timeout utility and using it to set the timeout (some systems use BusyBox, where it may have a different format than the standard).

This script allows containers or other services to wait for another service or database to become available before starting. This is especially useful when running multiple containers in a single composite application, where the containers need to be started in the correct sequence and ensure each other is ready.

Used Libraries

The Educa project uses various libraries to provide functionality and efficiency to the application. Here is a list of some of the more important libraries:

Django: Django is a Python-based web framework that provides many tools and features for developing web applications. It provides database management, authorization, URL handling, forms, templates, and other core components of a web application.
Django REST framework: This is a Django extension for building APIs. It provides a convenient way to create and process a RESTful API for interacting with an application.
Channels: Channels is a package that extends Django's ability to work with WebSocket and provides the ability to create real-time messaging using WebSocket.
Redis: Redis is a fast and scalable database management system used for caching data in an Educa application.
aioredis: This is an asynchronous Redis library, used to provide asynchronous communication with Redis in the asynchronous part of the application.
Django Debug Toolbar: This is a debugging tool for Django that provides information about queries and application performance.
Django Braces: A library that provides additional mixins for Django views and simplifies development.
Django Embed Video: A library for embedding videos from popular platforms like YouTube or Vimeo into Django templates.
Daphne: Daphne is a server that provides support for the ASGI (Asynchronous Server Gateway Interface) protocol to work with WebSockets.
Twisted: Twisted is an asynchronous networking library that is used with Daphne to provide WebSocket functionality.
Rest framework authtoken: A library for authenticating users through tokens in the Django REST Framework.
Pillow: Pillow is an image processing library used to load and manipulate images in an application.

This is just a small list of libraries used in the Educa project. There are other tools and libraries that can be used to implement additional functionality and improve application performance.

Name		Name	Last commit message	Last commit date
Latest commit History 33 Commits
config		config
data/db		data/db
educa		educa
Dockerfile		Dockerfile
LICENSE		LICENSE
README.md		README.md
docker-compose.yml		docker-compose.yml
requirements.txt		requirements.txt
wait-for-it.sh		wait-for-it.sh

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mikezigberman/educational_online_platform

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Project Name: Educational online platform

Introduction to the documentation of the project "Educational online platform":

Architecture

Examples of using

Brief description of the main project files

1. chat/views.py:

2. chat/urls.py:

3. chat/routing.py:

4. chat/consumers.py:

5. chat/templates/chat/room.py:

6. courses/views.py:

7. courses/urls.py:

8. courses/models.py:

9. courses/middleware.py:

10. courses/forms.py:

11. courses/fields.py:

12. courses/admin.py:

13. courses/api/views.py:

14. courses/api/urls.py:

15. courses/api/serializers.py:

16. courses/api/permissions.py:

17. students/views.py:

18. students/urls.py:

19. students/forms.py:

20. students/management/commands/enroll_reminder.py:

21. educa/urls.py:

22. educa/asgi.py:

23. educa/settings/prod.py:

24. educa/settings//local.py:

25. educa/settings/base.py:

26. docker-compose.yml

27. Dockerfile

28. requirements.txt

29. wait-for-it.sh

Used Libraries

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