python - Debugging Django admin panel bug -

when navigate admin interface particular model (the whole-table view), , hit 'save', error popping on usual red banner:

please correct errors below. 

needless couldn't make edits view, until experimented , fixed it.

here's class:

 class rolemapping(models.model):      min_length, max_length = 3, 40      role_name = models.charfield(unique=true, max_length=max_length, validators = [          minlengthvalidator(min_length, "field length should greater {}".format(min_length))      ])      role_type = models.foreignkey(roletype, null=true, blank=true ) 

here's admin interface model. but, flipping around of editable fields seems have made things work.

 class rolemapping(admin.modeladmin):      model = rolemapping      list_display = ('role_name', 'role_type',)      #list_editable = ('role_name', 'role_type',) # fails      #list_editable = ('role_name',) # fails      list_editable = ('role_type',) # works?! 

i can working, pretty easily, keeping role_type editable type. however, found out after bit of trial , error. i'm wondering:

1. what's django way of debugging these sorts of admin-panel-orm issues in future

2. why might have been failing in first place?

according the django admin docs:

note: list_editable interacts couple of other options in particular ways; should note following rules:

• any field in list_editable must in list_display. can’t edit field that’s not displayed!
• the same field can’t listed in both list_editable , list_display_links – field can’t both form , link.

you’ll validation error if either of these rules broken.

my guess violating second point , role_name default sole member of list_display_links.

to test this, set list_display_links = none or make field , add list_display , list_display_links.

edit:

i suspect following give want. i've added id first element of list_display. behind scenes, adds id instead of role_name list_display_links, frees role_name allowed in list_editable.

class rolemapping(admin.modeladmin):      model = rolemapping      list_display = ('id', 'role_name', 'role_type',)      list_editable = ('role_name', 'role_type',)