Add some blocks to course_about.html

[clemente]

Now that the new template inheritance was merged (https://github.com/edx/edx-platform/pull/16856) we can redefine specific blocks.
This adds some block names to existing code so that themes can redefine this blocks easily (without having to redefine the rest of the page).
This handles just course_about.html

JIRA tickets: None
Discussions: None
Dependencies: None
Screenshots: None
Sandbox URL: None
Merge deadline: None

Testing instructions:

1. Without this change (i.e. with your normal devstack server), go to http://localhost:18000/courses/course-v1:edX+DemoX+Demo_Course/about and save the HTML in a file
2. Start a server which includes this change: https://github.com/edx/edx-platform/pull/16856, cherry-pick the commit as needed.
3. Apply the patch in this PR, go to the same URL and save to another file
4. Compare files, the HTML should be the same (ignoring whitespace and django-debug-toolbar)
5. Check that no blocks are defined inside other blocks
6. Check that these blocks are like the rest of the other blocks. Or if you're not sure and want to test it, create a theme with a file lms/templates/course_about.html which redefines one of the blocks, e.g. <%block name="course_about_header">
7. Check that block names don't conflict with other block names used in templates
8. Check that names make sense

Reviewers

• @mtyaka

Author concerns: None
Settings: None

[mtyaka]

Why do we need an empty block right before the next block? Can we not include the content we want to add to course_info_before_header to the top of the header block?

[clemente]

Ok, I changed it as you said.

[mtyaka]

We will have to be careful with the naming. The main.html template (which this template inherits from)also (indirectly) contains a

element. It is currently not wrapped in a named block, but it could be in the future and would clash with theheaderblock from this template. We should name this one something likecourse_about_header`.

[mtyaka]

Maybe it would make sense to prefix all blocks introduced by a template by the template name.

[clemente]

I renamed blocks to use course_about prefix.

[mtyaka]

This looks good @clemente, but we still need the template block overrides commit. The commit has been merged to edx/edx-platform/master, but not into opencraft-release/ginkgo.1-pearson. It might make sense to do it in a separate PR though.

This is good to go after you squash the commits. 👍

• I tested this: I verified that the refactored page using named blocks locks and behaves the same as the original page.
• I read through the code
• I checked for accessibility issues
• Includes documentation N/A

[mtyaka]

We will also need to open an upstream PR with the same changes (unless the structure of the course_about.html page has changed significantly on master as compared to ginkgo).

[clemente]

but we still need the template block overrides commit.
@mtyaka #101

[clemente]

We will also need to open an upstream PR with the same changes

@mtyaka https://github.com/edx/edx-platform/pull/17091