[Music] Welcome to Django Admin.
After watching this video, you will be able to build an admin site to manage the content of an online course app without using the Model APIs in the shell, and customize the admin site. Let’s review the models we will be using for our online course app. The app has some common entities for an online learning application, such as Course, Lessons, Questions, and Choices. For persona, it has User, Learner, and Instructor. For actions, it has Course Enrollment and Question submission. With so many entities and their relationships, you can imagine how hard it would be for developers to build this online course app. Fortunately, Django provides developers with a very powerful Django admin site to manage this content with minimal coding efforts. Django framework has a clear separation between content publishers and users. Django provides a built-in admin site to manage content. For an online course app, instructors or site managers can use the admin site to add or edit courses, lessons, questions, and so on. Once the course is ready and published, students can enroll in the courses on the public site. Let’s start building a Django admin site by first creating an admin user for the admin site. First, run a command-line `python, manage.py, createsuperuser`. It will ask for credentials like username and password. After creating the super user, you can start the django server. Go to the admin site and login with the credential you just created. You will need to register your models to admin site so you can manage them. First, open the onlinecourse/admin.py file and add two lines: admin.site.register(Course) and admin.site.register(Instructor) to register Course and Instructor models now refresh the admin site. You can see that under the Onlinecourse section, we have added Courses and Instructors. Based on the model’s fields, Django will create different UI widgets. For instructors, Django creates a checkbox for the Boolean field for `Full_time` and numeric input for the integer field `total learners`. The Instructor model is inherited from User, so User is a related object to Instructor which has some common information such as name and date of birth. Here we can just convert a user to an instructor and determine if the instructor is full-time or not. Notice that although there is a field called Total learners, we probably wouldn’t want to manage this field in the admin site, but instead we would calculate it from the number of learners that are enrolled in the instructor’s course. Later, we will show you how to choose the fields you want to be managed in the admin site. We can create a course by entering its name, description, image for the course introduction, publication date, instructors, and so on. Developers may only want to include some of the model fields in the admin site and to specify a particular order. To select the fields to include, we create a model admin class and add a fields list with the field name we want to be included in the model. For example, for Course model, we create a CourseAdmin class with a list of fields we want to include in the admin site. The order will be pub_date, name, and description. Once we have defined CourseAdmin, we modify the admin.site.register method to add the CourseAdmin as the second parameter. After refreshing the admin site and trying to add a course, only pub date, name, and description are shown and can be edited. One course may contain many lessons and questions. Instead of adding each model one by one using its own admin form, we can add course and lessons together on one form, using admin.StackedInline or admin.TabularInline objects. We can create a LessonInLine object by specifying its model to be Lesson and `extra` to be 5, which means we want to add at most 5 lessons together with a course at the same time. In the CourseAdmin object which defines the course admin form, we add an inlines list to include the LessonInline class we defined. After refreshing the page, you can see that a Lessons section appears within the Course admin form. You can add the title, order, and content of a lesson, which will be added into the course automatically by Django. When we display multiple courses or other models in a tabular form, we need to determine the fields to appear in the table. For example, for a list of courses, we only want to show the name and publication date of the course in the table. We do this by adding a list_display with the list of fields we want to be shown on the course change table. After refreshing the page, the course change table now shows the course name and publication date columns as we defined them in list_display. The course change list may be very long, and you may want to be able to search and filter the list. To enable search and filter on the course change list, add the search_fields to include the fields you want to search and the list_filter to include the fields you want to filter. After refreshing the page, a Search box and a Filter menu appear on the course change list for you to search and filter the courses on the admin page. In this video, you learned that Django Admin site is very powerful and easy to use for site managers to manage content. The look and functions can also be customized.
