Source code for scripts.unique_slugify

import re
from django.template.defaultfilters import slugify

[docs]def unique_slugify(instance, value, slug_field_name='slug', queryset=None, slug_separator='-', case='lower'): """ 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 case == 'upper': slug = slug.upper() 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 queryset = queryset.exclude( # 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 _slug_strip(value, separator='-'): """ Cleans up a slug by removing slug separator characters that occur at the beginning or end of a slug. If an alternate separator is used, it will also replace any instances of the default '-' separator with the new separator. """ separator = separator or '' if separator == '-' or not separator: re_sep = '-' else: re_sep = '(?:-|%s)' % re.escape(separator) # Remove multiple instances and if an alternate separator is provided, # replace the default '-' separator. if separator != re_sep: value = re.sub('%s+' % re_sep, separator, value) # Remove separator from the beginning and end of the slug. if separator: if separator != '-': re_sep = re.escape(separator) value = re.sub(r'^%s+|%s+$' % (re_sep, re_sep), '', value) return value

Project Versions