Top-level workflow definition links broken after almost any change to definition, in Zope 4 and Zope 5

[seanupton]

BUG/PROBLEM REPORT

What I did:

• Create or visit existing workflow definition in ZMI
• Visit Transitions tab
• Add a transition
• Click any of the following top-level ZMI tabs: Worklists, Variables, States, Permissions

What I expect to happen:

• I expect the top-level tabs to go to expected destinations (not 404)

What actually happened:

• Tab links are relative to the wrong thing
• Only reasonable workaround is clicking breadcrumbs to reload your context, and then clicking top-level tabs

impact

• this makes it difficult to define workflows TTW (without a great deal of frustration and workaround)

in more detail — what actions are broken:

• Top level tabs break after any of the following actions:

  • States: assign a default state
  • States: delete a state
  • Transitions: add a transition
  • Transitions: delete a transition
  • Transitions: rename a transition
  • Worklist: delete a worklist
  • Worklist: rename a worklist
  • Variable: delete a variable
  • Variable: rename a variable

What version of Python and Zope/Addons I am using:

• This breaks in Zope 4 (Plone 5.2) and Zope 5 (Plone 6.x)
• Unsure: this might have been broken in Zope 2 in older Plone 5, and for a good long while we've been dealing with this.

What is failing here:

• links in DTML to top-level tabs inside a workflow definition are relative
• The classes implementing management views for DCWorkflow return instead of redirect after actions that mutate saved-state for the definition's states, transitions, worklists, or
• Ideally, the manage_main for States, Transitions, Worklists, and Variables classes would be smart enough to redirect back to manage_main instead of returning it with a different URL context.
• Likewise, manage_permissions should also redirect.

Workaround (which has limited testing) is a monkey patch:

def workflow_zmi_manage_main_wrapper(self, REQUEST, manage_tabs_message=None):
    view = REQUEST.steps[-1]
    target = 'manage_main'
    if view != target:
        query = '?manage_tabs_message={}'.format(manage_tabs_message or '')
        REQUEST.response.redirect(
            './{}/{}{}'.format(
                self.__class__.__name__.lower(),  # States -> states in url
                target,
                query if manage_tabs_message else '',
            )
        )
        return
    return self._old_manage_main(REQUEST, manage_tabs_message)

def workflow_zmi_manage_permissions_wrapper(
        self,
        REQUEST,
        manage_tabs_message=None
        ):
    if REQUEST.steps[-1] != 'manage_permissions':
        query = '?manage_tabs_message={}'.format(manage_tabs_message or '')
        REQUEST.response.redirect(
            '{}/manage_permissions{}'.format(
                self.absolute_url(),
                query if manage_tabs_message else '',
            )
        )
        return
    return self._old_manage_permissions(REQUEST, manage_tabs_message)

Which can be applied in ZCML via collective.monkepatcher like:

<!-- more elided, but you need to patch States, Transitions, Variables, Worklists with first function above -->
  <monkey:patch
      description="patch DCWorkflow ZMI Worklists manage_main to fix tab links"
      class="Products.DCWorkflow.Worklists.Worklists"
      original="manage_main"
      preserveOriginal="true"
      replacement=".monkeypatch.workflow_zmi_manage_main_wrapper"
      />

  <monkey:patch
      description="patch DCWorkflow ZMI manage_permissions to fix tab links"
      class="Products.DCWorkflow.WorkflowUIMixin.WorkflowUIMixin"
      original="manage_permissions"
      preserveOriginal="true"
      replacement=".monkeypatch.workflow_zmi_manage_permissions_wrapper"
      />

I am not 100% confident in the correctness or side-effect profile of this patching, though (it works for me, but I'm unclear if there is a better solution than redirecting, e.g. fixing the DTML tab links).

[petschki]

At least there's a similar report from 2019 #15