Sorting custom entry fields that contain numerical values

[GreyMatter17]

JabRef version 5.0 on Ubuntu 16.04, and on Windows 10, both installed using the installation files (.deb or .msi) downloaded from the JabRef website.
I assume the Java version will be that provided by the installer.

• I have NOT tested the latest development version from http://builds.jabref.org/master/ as I do not have the capabilities needed to do this. I have searched for other related Bug reports.
  The most relevant seem to be:
  Field properties - future implementation #978 Field properties - future implementation
  Sorting by title is broken #2200 Sorting by title is broken
  but both of these issues have been "Closed"

JabRef allows the user to add custom general entry fields that contain numerical values. All versions of JabRef prior to 5.0 allowed the Entry Table to be sorted in the numerical order of the value of such a custom field, simply by clicking on the column header.

However, with JabRef 5.0, the numerical (integer) values in this column are sorted in alphabetical order instead!
This means, for example that the numbers 1,2,3,10,13, 21
are sorted into the order 1,10,13,2,21,3
This suggests the numerical values are being treated as plain text.
I did not observe this problem with JabRef 4.3.1 or earlier versions.

Steps to reproduce the behavior:

1. Add a custom entry field to a BibTeX database using a JabRef version earlier than 5.0.
2. Populate this field with a range of positive integer values.
3. Open the BibTeX database file with JabRef 5.0.
4. Sort the Entry Table by the values in the Custom Entry field, by clicking on the relevant column header. The Table rows will be sorted by the alphabetical order of the number, not the numerical value.

Paste an excerpt of your log file here

[dextep]

Hi, following #6222 i think we have to implemented a new Comparator for that field. If you agree with me I could contribute by fixing this issue.

[Siedlerchr]

@dextep that would be cool. I think we need to specify a case for numeric/non numeric cases here that work for unknown fields as well

[dextep]

If someone want to take this issue feel free because i have less time than previews i think.

[dimitra-karadima]

@Siedlerchr Hi, I think I can handle this issue! Do you want me to add a special field like in the issue mentioned above or do you want to add the case for numeric/non numeric cases somewhere else?

[MootezSaaD]

@Siedlerchr Hi, I think I can handle this issue! Do you want me to add a special field like in the issue mentioned above or do you want to add the case for numeric/non numeric cases somewhere else?

If you want we can collaborate? I have a solution in mind (ofc if you don't mind)

[dimitra-karadima]

@Siedlerchr Hi, I think I can handle this issue! Do you want me to add a special field like in the issue mentioned above or do you want to add the case for numeric/non numeric cases somewhere else?

If you want we can collaborate? I have a solution in mind (ofc if you don't mind)

Of course! That would be awesome!

[github-actions]

This issue has been inactive for half a year. Since JabRef is constantly evolving this issue may not be relevant any longer and it will be closed in two weeks if no further activity occurs.

As part of an effort to ensure that the JabRef team is focusing on important and valid issues, we would like to ask if you could update the issue if it still persists. This could be in the following form:

• If there has been a longer discussion, add a short summary of the most important points as a new comment (if not yet existing).
• Provide further steps or information on how to reproduce this issue.
• Upvote the initial post if you like to see it implemented soon. Votes are not the only metric that we use to determine the requests that are implemented, however, they do factor into our decision-making process.
• If all information is provided and still up-to-date, then just add a short comment that the issue is still relevant.

Thank you for your contribution!