Fields in list_display_links are not links if their values are whitespace.

[Antoliny]

In the admin list page, when the value of list_display is set to 'str' (default option), if the model's __str__ is composed entirely of blank values, the link will not appear.

class Post(models.Model):
    title = models.CharField(max_length=128)
    content = models.TextField()
    like = models.IntegerField(default=0)
    
    def __str__(self):
        return "       "

In a typical situation it would be fine, but when __str__ is set in list_display_links, <a> tag innerHTML becomes empty, so resulting in the loss of the link functionality to navigate to the object.

class PostAdmin(admin.ModelAdmin):
    list_display_links = ["__str__"]
    list_display = ["__str__", "title"]

[Tim Graham]

What's the use case for str being a blank value and what is your proposal to fix it?

[Antoliny]

Replying to Tim Graham:

What's the use case for str being a blank value and what is your proposal to fix it?

I think that a __str__ value being composed entirely of blank spaces is extremely rare unless it's a user mistake. However, for fields, when they consist only of blank spaces, they are treated as None and return the default empty_value("-"). Similarly, when __str__ is composed of only blank spaces, it should return a default empty_value like "-" so that it can function as a link when set in list_display_links.
It seems that adding a bit of logic to the item_for_result(contrib.admin.templatetags.admin_list.py) function would suffice.

[Antoliny]

​PR

[Sarah Boyce <42296566+sarahboyce@…>]

In e262d535:

Fixed #36114 -- Fixed link visibility when list_display_links field contains only whitespace.

[Sarah Boyce <42296566+sarahboyce@…>]

In 5242220:

[5.2.x] Fixed #36114 -- Fixed link visibility when list_display_links field contains only whitespace.

Backport of e262d5355d82901f81fba6c7015643c2b87125bf from main.