Manage duplication between projects

[xi]

Our projects tend to have a large overlap in terms of features and UI. In the past we tried to limit duplication by sharing a lot of code. The downside of this was that the shared code became very abstract and hard to reason about.

With the switch from a3 to a4, we went the other way and did a lot of duplication. In order to find a good balance, we should think about ways to limit duplication while keeping it simple. At the very least, we should have an understanding of:

• what is our current approach to code duplication between projects?
• what are its advantages and limitations?

According to @2e2a, we already have a good balance in the python code. The same is true for CSS. So for now we can concentrate on the templates.

We already tried to work on this in some pull requests (#206, #237, #239). We found that the templates are in fact very similar, but also different in some key places:

• similar but different permissions (e.g. create_idea / create_proposal) (see refactor item detail templates #206)
• similar but different URL names (e.g. idea-create / proposal-create) (see refactor item detail templates #206)
• similar but different navigation (breadcrumbs)
• different terms that appear in natural language sentences (e.g. "Delete this idea" / "Delete this proposal")

[xi]

The current approach of duplicating a lot is fine. Once this becomes a real issue, we can reopen this.