A Django 2.2 Admin Mixin that supports foreign key relationship links with list_links attribute

listlinksmixin.py

from django.urls import reverse
from django.utils.html import format_html

class ListLinksMixin(object):
    """
    Support for list_links attribute.  Items in list_links must also be in list_display
    
    Usage to make 'fieldTwo' a link:
    list_display = ('fieldOne', 'fieldTwo',)
    list_links = ('fieldTwo',)
    
    """
    list_links = []
 
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if self.list_links:
            for field in self.list_links:
                if field in self.list_display:
                    func_name = field + '_link'
                    setattr(self, func_name, self._generate_link_func(field))
                    self.list_display = [func_name if item ==
                                         field else item for item in self.list_display]
 
    def _generate_link_func(self, field):
        def _func(item):
            instance = getattr(item, field)
            if not instance:
                return None
            url = reverse(
                f'admin:{instance._meta.app_label}_{instance._meta.model_name}_change', args=[instance.pk])
            return format_html(f'<a href="{url}">{instance}</a>')
 
        _func.short_description = field
        _func.admin_order_field = field
 
        return _func

Thanks for sharing the gist, I found it on SO. I noticed that it causes an error when the value of the related field is None. Here's a simple patch to fix it:

     def _generate_link_func(self, field):
         def _func(item):
             instance = getattr(item, field)
+            if not instance:
+                return None
             url = reverse(
                 f'admin:{instance._meta.app_label}_{instance._meta.model_name}_change', args=[instance.pk])
             return format_html(f'<a href="{url}">{instance}</a>')

Thanks for sharing the gist, I found it on SO. I noticed that it causes an error when the value of the related field is None. Here's a simple patch to fix it:

Thanks I have updated the gist

Thank you for this. It's unbelievable that django doesn't support this out of the box.

def __init__(self, *args, **kwargs):
    super().__init__(*args, **kwargs)
    if self.list_links:
        for field in self.list_links:
            func_name = field + '_link'
            setattr(self, func_name, self._generate_link_func(field))
            if field in self.list_display:
                self.list_display = [
                    func_name if item == field
                    else item for item in self.list_display
                ]
            if field in self.readonly_fields:
                self.readonly_fields = [
                    func_name if item == field
                    else item for item in self.readonly_fields
                ]

This change allows the links to be in readonly_fields as well (either or both), which is nice if your list_display is already crowded and you only want it if the viewer is viewing the particular model. I also find it disorienting when something is in list_display and not in the model view.

It probably could be a bit cleaner than if-ing each fields list, but it works great.