Resolve request kwargs while defining MenuItem

[jokiefer]

related to #19

I struggled also about the issue to catch the current pk attribute from the current request and pass it into the menu.

I've got the following urls.py for example:

app_name = 'structure'
urlpatterns = [
   ...
    path('groups', MrMapGroupTableView.as_view(), name='group_overview'),
    path('groups/new', NewMrMapGroup.as_view(), name='group_new'),
    path('groups/<pk>', MrMapGroupDetailView.as_view(), name='group_details'),
    path('groups/<pk>/members', MrMapGroupMembersTableView.as_view(), name='group_members'),
    path('groups/<pk>/edit', EditGroupView.as_view(), name='group_edit'),
   ...
]

How can i resolve the current requested pk from the request kwargs for example in the menus.py:

# Define children for the group menu
group_details_children = (
    MenuItem("Edit Group",
             reverse('structure:group_edit', args=pk), # pk not resolved here for now
             weight=10,
             icon="user"),
    MenuItem(_("Members"),
             reverse('structure:group_members', args=pk), # pk not resolved here for now
             weight=20,
    MenuItem(_("Publishers"),
             reverse('structure:group_publishers', args=pk), # pk not resolved here for now
             weight=30,
)

# Add a My Account item to our user menu
Menu.add_item("group_details", MenuItem(_("Details"),
                                        reverse('structure:group_details', args=pk), # pk not resolved here for now
                                        weight=10,
                                        children=group_details_children))

[jokiefer]

I've made it by customizing the MenuItem class as shown in the code snippet below.

from django.http import HttpRequest
from django.urls import reverse
from menu import MenuItem, Menu
from django.utils.translation import gettext as _


def resolve_url(request: HttpRequest, view_name: str):
    return reverse(view_name, args=[request.resolver_match.kwargs.get('pk'), ])


class CustomMenuItem(MenuItem):

    def process(self, request):
        # evaluate our url
        if callable(self.url):
            self.url = self.url(request, self.view_name)
        super().process(request)


children = (
    CustomMenuItem(_("Edit Group"),
                   resolve_url,
                   weight=10,
                   view_name='structure:group_edit'),
    CustomMenuItem(_("Delete Group"),
                   resolve_url,
                   weight=20,
                   view_name='structure:group_remove',),
    CustomMenuItem(_("Members"),
                   resolve_url,
                   weight=30,
                   view_name='structure:group_members',),
    CustomMenuItem(_("Publishes for"),
                   resolve_url,
                   weight=40,
                   view_name='structure:group_publisher_overview'),
)

Menu.add_item('group_details', CustomMenuItem(_("Details"),
                                              resolve_url,
                                              weight=10,
                                              children=children,
                                              view_name='structure:group_details'))

I'm wondering about that this isn't already implemented. Maybe a PR with the enhancement of a simple check if self.url callable would be enough to add this feature by default. Or do i misunderstood the documentation somewhere?

[timnyborg]

I tried to do something similar, and ran into the same issue that url won't accept a callable (but really should). However, children can accept a callable which takes request, so you can just replace the tuple with a function:

def children(request):
    pk = request.resolver_match.kwargs.get('pk')
    return [
        CustomMenuItem(_("Edit Group"),
                   reverse('structure:group_edit', args=[pk]),
                   weight=10,
                   view_name='structure:group_edit'),
    ...
    ]

I think your custom class is required for callable URLs at the top of the hierarchy, though.

[jokiefer]

@timnyborg

Nice. Pretty good solution to define the children's, cause you could also drop the subclass CustomMenuItem.

I think your custom class is required for callable URLs at the top of the hierarchy, though.

Yep - Cause there is no callable check. If so, we could adapt your solution again, without defining the view_name attr.

[timnyborg]

@jokiefer
I've adapted your code into pull request #71, which works on parent and child nodes alike.