Admin revert enabled/disabled, view only permissions

[erikvw]

In some scenarios, it is not ideal to allow users to revert a model instance to a previous version.
Django 2.1 introduced view permissions which, if integrated into DSH, would give an administrator the ability to allow a user to add/change a model but not revert to a previous instance through the model's history.

Related to:

related to #529 and #632

Description

The SimpleHistoryAdmin reviews the historical model instance permissions instead of just the model instance by overriding the has_xxxx_permission methods in ModelAdmin.

• enable this feature through settings (SIMPLE_HISTORY_PERMISSIONS_ENABLED);

• honor superuser privileges;

• user/group permissions granted for the historical model cannot exceed those of the model. That is, granting view and change permissions for the historical model but only view permission for the model means the user has view permission only for the historical model;

• text on the changelist and form becomes context sensitive (change permission vs view permission);

• setting SIMPLE_HISTORY_REVERT_DISABLED=True limits all users (other than superuser) to view access. (this works for all Django versions)

• the [Revert] button is changed to a [Close] button if the user has:
  -- if Django >= 2.1, feature is disabled, and has view on model;
  -- if Django >= 2.1, feature is enable and has view model permission and view historical model permission;
  -- if settings. SIMPLE_HISTORY_REVERT_DISABLED = True (regardless of Django version).

How Has This Been Tested?

See tests in test_admin_with_permissions.py

A few tests in test_admin.py required very minor modifications.

Screenshots (if appropriate):

For a user with "view" only permission on a historical object, the changelist looks like this:

and the form looks like this:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have run the make format command to format my code
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have added my name and/or github handle to AUTHORS.rst
• I have added my change to CHANGES.rst
• All new and existing tests passed.

[erikvw]

was #529, still in progress. Still to review all comments on #529.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@8bcf4c4). Click here to learn what that means.
The diff coverage is 100%.

@@            Coverage Diff            @@
##             master     #631   +/-   ##
=========================================
  Coverage          ?   97.99%           
=========================================
  Files             ?       17           
  Lines             ?      946           
  Branches          ?      140           
=========================================
  Hits              ?      927           
  Misses            ?        7           
  Partials          ?       12

Impacted Files	Coverage Δ
simple_history/admin.py	100% <100%> (ø)

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[dwasyl]

@erikvw this is just an updated version of your last PR right? Any chance that it'd be ready to merge soon? I'd love to see this feature in a current build.

[JohnieBraaf]

I also am in need of this PR, as it would resolve this issue: #704

[Leo5677]

I also am in need of this PR, as it would resolve this issue: #704

Também preciso deste PR, pois isso resolveria o problema: # 704

Yes... I also need!!!

[jeking3]

This needs to be rebased.

[jeking3]

@erikvw This needs to be rebased.

[rolandcrosby-check]

@jeking3 I rebased the changes onto latest master and put the resulting commit up as a separate PR here: #915. I haven't run the full test suite or made any functional changes, so I'm not sure if anything has broken in the year and a half since this PR was originally opened.

@erikvw if you like, you can pull the rebased commit into your branch to continue addressing review feedback; I'm just hoping to help move this along however I can, as I'd really like to be able to use this feature eventually.

[jeking3]

@rolandcrosby-check re #915 that needs to be rebased on master so CI tests can run.

[rolandcrosby-check]

@jeking3 I'm not sure if I'll get a chance to do that, I just did the original rebase with the goal of helping @erikvw move this along. If anyone else wants to pick this up and re-rebase #915 I'd welcome that.

[erikvw]

see #1017 , this might be a better option.