General: Add capability to remove course icon

[rriyaldhi]

Checklist

General

• I tested all changes and their related features with all corresponding user types on a test server.
• Language: I followed the guidelines for inclusive, diversity-sensitive, and appreciative language.
• I chose a title conforming to the naming conventions for pull requests.

Client

• I followed the coding and design guidelines and ensured that the layout is responsive.
• Following the theming guidelines, I specified colors only in the theming variable files and checked that the changes look consistent in both the light and the dark theme.
• I added multiple integration tests (Jest) related to the features (with a high test coverage), while following the test guidelines.
• I documented the TypeScript code using JSDoc style.
• I added multiple screenshots/screencasts of my UI changes.

Motivation and Context

#5526

Description

When Delete Icon Button is clicked, the course icon is set to null. When the Save Button is clicked, the Course Update API will be called. The Course Update API will set the course icon to null and delete the previous course icon file.

Steps for Testing

Prerequisites:

• 1 Instructor
• 1 Course with Icon

1. Log in to Artemis
2. Navigate to Course Administration
3. Open Course Detail page
4. Click Edit Button
5. Click Delete Button under the Course Icon
6. Click Save
7. The Course Icon should be removed

Review Progress

Code Review

• Review 1
• Review 2

Manual Tests

• Test 1
• Test 2

Test Coverage

Class/File	Branch	Line
course-update.component.ts	70.24%	87%

Screenshots

Desktop

Mobile

[ge65cer]

Tested on TS1, works! My suggestions:

• Remove the confirmation dialog, as clicking on "cancel" aborts the course editing and the icon is still there. You already need to confirm deleting by clicking on "save".
• Move the button next to the upload form, maybe label it "Remove Icon". In my opinion it can also does not need to be red colored, as it is not a destructive action.

Feel free to wait for feedback from other reviewers before applying these requests.

[JohannesStoehr]

Looked through the code and left some comments.
I mostly agree with Moritz‘ comments, but I actually like the red color of the button, since you’re still deleting something, even though you have to save the modification afterwards.

[JohannesStoehr]

I think you can also leave out the _ completely when it’s unused

[JonasGeigerTUM]

Deleting the course icon works as expected. Tested on ts1

[LiaLism]

Removing icon worked.

[JohannesStoehr]

Rechecked thee code changes, looks good to me