I have a major experience in Python, but just get acknowledged with Plone a few days ago.
I need to implement the next thing:
On any post published, I need to add a custom dropdown item (smth like "Category of this post"), so everybody will see this category (finally, it should be a text with a color/image).
I went through the docs but got stuck with understanding where should I look into to solve this issue.
I'd be glad if you provide me with any link related to the problem described, because currently I think I'm digging in a wrong way...
The idea is - user needs to be able to create a post with a few more custom details: category, priority and source. These characteristics are restricted to be of fixed choices (e.g., priority is one of "High", "Medium", "Low").
In the post page, these characteristics should be displayed with a text value and a related color (like "High" and red colored rectangle, for example).
The closest similar view is a bugtracker or Trello I think, but on Plone and customized.
As I understand, it must be smth like a dropdown widget during creation of the post. But I'm not sure where to dig further.
Well, probably I used a term from Wordpress area, didn't I?
So, for example, I have a basic demo Plone app (lets say - from docker hub) with "News" item in the menu.
Under "News", I can create new <posts? or pages? or whatever?> with some content. So the "post", in my words, means "a publishment".
Try keywords or tags in the 'categorisation' tab when editing a page or newsitems.
They will render as link at the bottom of the page. See https://www.plone-demo.info/news/newsitem-1 for an example.
Sounds like you want to create your own custom content type or add some extra fields to the schema of an existing content type like a "News Item" or "Page". There is plenty of documentation on doing that either via the control panel using the dexterity schema editor, or via creating your own plugin and writing python.
The next step you mentioned is customising the "view" to change the colours based on the what is stored on the content object. There are a number of ways to do that. Personally I tend to use diazo to create a custom theme and specify some rules to adjust the html based on the basic html rendered. but you can also use the ambidexterity plugin to override the template on a lower level or if you create a plugin you can do the same there. themefragments will let you do the same thing.