(instance, value, slug_field_name='slug', queryset=None,
                   slug_separator='-')
Calculates and stores a unique slug of ``value`` for an instance.

    ``slug_field_name`` should be a string matching the name of the field to
    store the slug in (and the field to check against for uniqueness).

    ``queryset`` usually doesn't need to be explicitly provided - it'll default
    to using the ``.all()`` queryset from the model's default manager.
Calculates and stores a unique slug of ``value`` for an instance.
Calculates and stores a unique slug of value for an instance .
def unique_slugify(instance, value, slug_field_name='slug', queryset=None,
                   slug_separator='-'):
    """
    Calculates and stores a unique slug of ``value`` for an instance.

    ``slug_field_name`` should be a string matching the name of the field to
    store the slug in (and the field to check against for uniqueness).

    ``queryset`` usually doesn't need to be explicitly provided - it'll default
    to using the ``.all()`` queryset from the model's default manager.
    """
    slug_field = instance._meta.get_field(slug_field_name)

    slug = getattr(instance, slug_field.attname)
    slug_len = slug_field.max_length

    # Sort out the initial slug, limiting its length if necessary.
    slug = slugify(value)
    if slug_len:
        slug = slug[:slug_len]
    slug = _slug_strip(slug, slug_separator)
    original_slug = slug

    # Create the queryset if one wasn't explicitly provided and exclude the
    # current instance from the queryset.
    if queryset is None:
        queryset = instance.__class__._default_manager.all()
    if instance.pk:
        queryset = queryset.exclude(pk=instance.pk)

    # Find a unique slug. If one matches, at '-2' to the end and try again
    # (then '-3', etc).
    next = 2
    while not slug or queryset.filter(**{slug_field_name: slug}):
        slug = original_slug
        end = '%s%s' % (slug_separator, next)
        if slug_len and len(slug) + len(end) > slug_len:
            slug = slug[:slug_len - len(end)]
            slug = _slug_strip(slug, slug_separator)
        slug = '%s%s' % (slug, end)
        next += 1

    setattr(instance, slug_field.attname, slug)
def unique_slugify ( instance , value , slug_field_name = 'slug' , queryset = None , slug_separator = '-' ) : slug_field = instance . _meta . get_field ( slug_field_name ) slug = getattr ( instance , slug_field . attname ) slug_len = slug_field . max_length # Sort out the initial slug, limiting its length if necessary. slug = slugify ( value ) if slug_len : slug = slug [ : slug_len ] slug = _slug_strip ( slug , slug_separator ) original_slug = slug # Create the queryset if one wasn't explicitly provided and exclude the # current instance from the queryset. if queryset is None : queryset = instance . __class__ . _default_manager . all ( ) if instance . pk : queryset = queryset . exclude ( pk = instance . pk ) # Find a unique slug. If one matches, at '-2' to the end and try again # (then '-3', etc). next = 2 while not slug or queryset . filter ( * * { slug_field_name : slug } ) : slug = original_slug end = '%s%s' % ( slug_separator , next ) if slug_len and len ( slug ) + len ( end ) > slug_len : slug = slug [ : slug_len - len ( end ) ] slug = _slug_strip ( slug , slug_separator ) slug = '%s%s' % ( slug , end ) next += 1 setattr ( instance , slug_field . attname , slug )