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Diffstat (limited to 'lib/tagging/utils.py')
| -rw-r--r-- | lib/tagging/utils.py | 263 |
1 files changed, 0 insertions, 263 deletions
diff --git a/lib/tagging/utils.py b/lib/tagging/utils.py deleted file mode 100644 index e89bab0..0000000 --- a/lib/tagging/utils.py +++ /dev/null @@ -1,263 +0,0 @@ -""" -Tagging utilities - from user tag input parsing to tag cloud -calculation. -""" -import math -import types - -from django.db.models.query import QuerySet -from django.utils.encoding import force_unicode -from django.utils.translation import ugettext as _ - -# Python 2.3 compatibility -try: - set -except NameError: - from sets import Set as set - -def parse_tag_input(input): - """ - Parses tag input, with multiple word input being activated and - delineated by commas and double quotes. Quotes take precedence, so - they may contain commas. - - Returns a sorted list of unique tag names. - """ - if not input: - return [] - - input = force_unicode(input) - - # Special case - if there are no commas or double quotes in the - # input, we don't *do* a recall... I mean, we know we only need to - # split on spaces. - if u',' not in input and u'"' not in input: - words = list(set(split_strip(input, u' '))) - words.sort() - return words - - words = [] - buffer = [] - # Defer splitting of non-quoted sections until we know if there are - # any unquoted commas. - to_be_split = [] - saw_loose_comma = False - open_quote = False - i = iter(input) - try: - while 1: - c = i.next() - if c == u'"': - if buffer: - to_be_split.append(u''.join(buffer)) - buffer = [] - # Find the matching quote - open_quote = True - c = i.next() - while c != u'"': - buffer.append(c) - c = i.next() - if buffer: - word = u''.join(buffer).strip() - if word: - words.append(word) - buffer = [] - open_quote = False - else: - if not saw_loose_comma and c == u',': - saw_loose_comma = True - buffer.append(c) - except StopIteration: - # If we were parsing an open quote which was never closed treat - # the buffer as unquoted. - if buffer: - if open_quote and u',' in buffer: - saw_loose_comma = True - to_be_split.append(u''.join(buffer)) - if to_be_split: - if saw_loose_comma: - delimiter = u',' - else: - delimiter = u' ' - for chunk in to_be_split: - words.extend(split_strip(chunk, delimiter)) - words = list(set(words)) - words.sort() - return words - -def split_strip(input, delimiter=u','): - """ - Splits ``input`` on ``delimiter``, stripping each resulting string - and returning a list of non-empty strings. - """ - if not input: - return [] - - words = [w.strip() for w in input.split(delimiter)] - return [w for w in words if w] - -def edit_string_for_tags(tags): - """ - Given list of ``Tag`` instances, creates a string representation of - the list suitable for editing by the user, such that submitting the - given string representation back without changing it will give the - same list of tags. - - Tag names which contain commas will be double quoted. - - If any tag name which isn't being quoted contains whitespace, the - resulting string of tag names will be comma-delimited, otherwise - it will be space-delimited. - """ - names = [] - use_commas = False - for tag in tags: - name = tag.name - if u',' in name: - names.append('"%s"' % name) - continue - elif u' ' in name: - if not use_commas: - use_commas = True - names.append(name) - if use_commas: - glue = u', ' - else: - glue = u' ' - return glue.join(names) - -def get_queryset_and_model(queryset_or_model): - """ - Given a ``QuerySet`` or a ``Model``, returns a two-tuple of - (queryset, model). - - If a ``Model`` is given, the ``QuerySet`` returned will be created - using its default manager. - """ - try: - return queryset_or_model, queryset_or_model.model - except AttributeError: - return queryset_or_model._default_manager.all(), queryset_or_model - -def get_tag_list(tags): - """ - Utility function for accepting tag input in a flexible manner. - - If a ``Tag`` object is given, it will be returned in a list as - its single occupant. - - If given, the tag names in the following will be used to create a - ``Tag`` ``QuerySet``: - - * A string, which may contain multiple tag names. - * A list or tuple of strings corresponding to tag names. - * A list or tuple of integers corresponding to tag ids. - - If given, the following will be returned as-is: - - * A list or tuple of ``Tag`` objects. - * A ``Tag`` ``QuerySet``. - - """ - from tagging.models import Tag - if isinstance(tags, Tag): - return [tags] - elif isinstance(tags, QuerySet) and tags.model is Tag: - return tags - elif isinstance(tags, types.StringTypes): - return Tag.objects.filter(name__in=parse_tag_input(tags)) - elif isinstance(tags, (types.ListType, types.TupleType)): - if len(tags) == 0: - return tags - contents = set() - for item in tags: - if isinstance(item, types.StringTypes): - contents.add('string') - elif isinstance(item, Tag): - contents.add('tag') - elif isinstance(item, (types.IntType, types.LongType)): - contents.add('int') - if len(contents) == 1: - if 'string' in contents: - return Tag.objects.filter(name__in=[force_unicode(tag) \ - for tag in tags]) - elif 'tag' in contents: - return tags - elif 'int' in contents: - return Tag.objects.filter(id__in=tags) - else: - raise ValueError(_('If a list or tuple of tags is provided, they must all be tag names, Tag objects or Tag ids.')) - else: - raise ValueError(_('The tag input given was invalid.')) - -def get_tag(tag): - """ - Utility function for accepting single tag input in a flexible - manner. - - If a ``Tag`` object is given it will be returned as-is; if a - string or integer are given, they will be used to lookup the - appropriate ``Tag``. - - If no matching tag can be found, ``None`` will be returned. - """ - from tagging.models import Tag - if isinstance(tag, Tag): - return tag - - try: - if isinstance(tag, types.StringTypes): - return Tag.objects.get(name=tag) - elif isinstance(tag, (types.IntType, types.LongType)): - return Tag.objects.get(id=tag) - except Tag.DoesNotExist: - pass - - return None - -# Font size distribution algorithms -LOGARITHMIC, LINEAR = 1, 2 - -def _calculate_thresholds(min_weight, max_weight, steps): - delta = (max_weight - min_weight) / float(steps) - return [min_weight + i * delta for i in range(1, steps + 1)] - -def _calculate_tag_weight(weight, max_weight, distribution): - """ - Logarithmic tag weight calculation is based on code from the - `Tag Cloud`_ plugin for Mephisto, by Sven Fuchs. - - .. _`Tag Cloud`: http://www.artweb-design.de/projects/mephisto-plugin-tag-cloud - """ - if distribution == LINEAR or max_weight == 1: - return weight - elif distribution == LOGARITHMIC: - return math.log(weight) * max_weight / math.log(max_weight) - raise ValueError(_('Invalid distribution algorithm specified: %s.') % distribution) - -def calculate_cloud(tags, steps=4, distribution=LOGARITHMIC): - """ - Add a ``font_size`` attribute to each tag according to the - frequency of its use, as indicated by its ``count`` - attribute. - - ``steps`` defines the range of font sizes - ``font_size`` will - be an integer between 1 and ``steps`` (inclusive). - - ``distribution`` defines the type of font size distribution - algorithm which will be used - logarithmic or linear. It must be - one of ``tagging.utils.LOGARITHMIC`` or ``tagging.utils.LINEAR``. - """ - if len(tags) > 0: - counts = [tag.count for tag in tags] - min_weight = float(min(counts)) - max_weight = float(max(counts)) - thresholds = _calculate_thresholds(min_weight, max_weight, steps) - for tag in tags: - font_set = False - tag_weight = _calculate_tag_weight(tag.count, max_weight, distribution) - for i in range(steps): - if not font_set and tag_weight <= thresholds[i]: - tag.font_size = i + 1 - font_set = True - return tags |