Fix order of fields in bib file

[tobiasdiez]

The fields are no longer serialized in alphabetic order. This was introduced in #6152.

[Siedlerchr]

Why do you revert this? This will totally disable the funcitonality of the reodering of fields in the entry editor because the serializer is used for preferences as well!

[tobiasdiez]

I didn't touched the entry editor at all. Its only about writing fields to the bib file. We discussed serialization formats at length and the result was that we want the fields to be alphabetic.

Where is the bib serializer used in the preferences?

[Siedlerchr]

Custom Entry types:
storeBibEntryTypes() in JabRefPreferences
bibEntryTypes.forEach(type -> prefsNode.put(type.getType().getName(), BibEntryTypesManager.serialize(type)));

[tobiasdiez]

How is this code related to my changes in BibEntryWriter ?

[Siedlerchr]

I don't remember exactly but please test: Modify article entry in the custom entry types dialog, drag and drop the fields order. Save the database and reopen.
And also please test if a custom entry type is correctly serialized in order as defined. I think the latter was the problem why I changed it.

[koppor]

Note to self: The diff at the test at https://github.com/JabRef/jabref/pull/6152/files#diff-507143b1fef690b2d56fffdd22b93888 indicates, that fields are written in "priority" order during writing. This was decided a long time ago in our rewrite of the writing to support users MANUALLY reading the .bib file. E.g., when collaborating with other users using Emacs, TeXStudio or some other tooling to edit the .bib files.

[koppor]

@tobiasdiez Seems, we need to collect the PRs and add an ADR, since this a very important topic.

[koppor]

I reviewed the history from JabRef 2.0 to 5.0. See JabRef/blog.jabref.org#47.

From JabRef 3.6 to 5.0 we sorted first the required fields then the optional fields. https://github.com/JabRef/blog.jabref.org/blob/add-bibtex-file-changes-over-time/_posts/2020-08-20-bibtex-file-changes-over-time.md#jabref-36-to-50

Took me long to understand the comment #6750 (comment).

Need to check the new implementation with https://github.com/JabRef/blog.jabref.org/pull/47/files#diff-867594d61e2704030501c6b58f99c9d4.

Proposal:

• This PR has to go in for the v5.1 release.
• At JabCon, we can discuss a more "intuitive" field ordering (as implied by Allow reordering of custom entry types fields #6152).

[tobiasdiez]

I agree, this PR should go into 5.1. I'll merge it now, since I didn't experience any issues with it.

[Siedlerchr]

I also did a quick test with Customize Entry types dialog and changing the order of the fields and could not find any problems as well. So it's fine.