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diff --git a/docs/.svn/all-wcprops b/docs/.svn/all-wcprops new file mode 100644 index 0000000..6104b64 --- /dev/null +++ b/docs/.svn/all-wcprops @@ -0,0 +1,11 @@ +K 25 +svn:wc:ra_dav:version-url +V 28 +/svn/!svn/ver/133/trunk/docs +END +overview.txt +K 25 +svn:wc:ra_dav:version-url +V 41 +/svn/!svn/ver/133/trunk/docs/overview.txt +END diff --git a/docs/.svn/entries b/docs/.svn/entries new file mode 100644 index 0000000..643c736 --- /dev/null +++ b/docs/.svn/entries @@ -0,0 +1,62 @@ +9 + +dir +147 +http://django-tagging.googlecode.com/svn/trunk/docs +http://django-tagging.googlecode.com/svn + + + +2008-04-30T22:29:01.189094Z +133 +jonathan.buchanan + + +svn:special svn:externals svn:needs-lock + + + + + + + + + + + +83e7428b-ec2a-0410-86f2-bf466d0e5e72 + +overview.txt +file + + + + +2008-08-21T18:05:41.000000Z +6ff98ba2ec163f1556bc41693647443a +2008-04-30T22:29:01.189094Z +133 +jonathan.buchanan +has-props + + + + + + + + + + + + + + + + + + + + +29385 + diff --git a/docs/.svn/format b/docs/.svn/format new file mode 100644 index 0000000..ec63514 --- /dev/null +++ b/docs/.svn/format @@ -0,0 +1 @@ +9 diff --git a/docs/.svn/prop-base/overview.txt.svn-base b/docs/.svn/prop-base/overview.txt.svn-base new file mode 100644 index 0000000..bdbd305 --- /dev/null +++ b/docs/.svn/prop-base/overview.txt.svn-base @@ -0,0 +1,5 @@ +K 13 +svn:eol-style +V 6 +native +END diff --git a/docs/.svn/text-base/overview.txt.svn-base b/docs/.svn/text-base/overview.txt.svn-base new file mode 100644 index 0000000..9641f03 --- /dev/null +++ b/docs/.svn/text-base/overview.txt.svn-base @@ -0,0 +1,912 @@ +============== +Django Tagging +============== + +A generic tagging application for `Django`_ projects, which allows +association of a number of tags with any Django model instance and makes +retrieval of tags simple. + +.. _`Django`: http://www.djangoproject.com + +.. contents:: + :depth: 3 + + +Installation +============ + +Installing an official release +------------------------------ + +Official releases are made available from +http://code.google.com/p/django-tagging/ + +Source distribution +~~~~~~~~~~~~~~~~~~~ + +Download the .zip distribution file and unpack it. Inside is a script +named ``setup.py``. Enter this command:: + + python setup.py install + +...and the package will install automatically. + +Windows installer +~~~~~~~~~~~~~~~~~ + +A Windows installer is also made available - download the .exe +distribution file and launch it to install the application. + +An uninstaller will also be created, accessible through Add/Remove +Programs in your Control Panel. + +Installing the development version +---------------------------------- + +Alternatively, if you'd like to update Django Tagging occasionally to pick +up the latest bug fixes and enhancements before they make it into an +official release, perform a `Subversion`_ checkout instead. The following +command will check the application's development branch out to an +``tagging-trunk`` directory:: + + svn checkout http://django-tagging.googlecode.com/svn/trunk/ tagging-trunk + +Add the resulting folder to your `PYTHONPATH`_ or symlink (`junction`_, +if you're on Windows) the ``tagging`` directory inside it into a +directory which is on your PYTHONPATH, such as your Python +installation's ``site-packages`` directory. + +You can verify that the application is available on your PYTHONPATH by +opening a Python interpreter and entering the following commands:: + + >>> import tagging + >>> tagging.VERSION + (0, 3, 'pre') + +When you want to update your copy of the Django Tagging source code, run +the command ``svn update`` from within the ``tagging-trunk`` directory. + +.. caution:: + + The development version may contain bugs which are not present in the + release version and introduce backwards-incompatible changes. + + If you're tracking trunk, keep an eye on the `CHANGELOG`_ and the + `backwards-incompatible changes wiki page`_ before you update your + copy of the source code. + +.. _`Subversion`: http://subversion.tigris.org +.. _`PYTHONPATH`: http://docs.python.org/tut/node8.html#SECTION008110000000000000000 +.. _`junction`: http://www.microsoft.com/technet/sysinternals/FileAndDisk/Junction.mspx +.. _`CHANGELOG`: http://django-tagging.googlecode.com/svn/trunk/CHANGELOG.txt +.. _`backwards-incompatible changes wiki page`: http://code.google.com/p/django-tagging/wiki/BackwardsIncompatibleChanges + +Using Django Tagging in your applications +----------------------------------------- + +Once you've installed Django Tagging and want to use it in your Django +applications, do the following: + + 1. Put ``'tagging'`` in your ``INSTALLED_APPS`` setting. + 2. Run the command ``manage.py syncdb``. + +The ``syncdb`` command creates the necessary database tables and +creates permission objects for all installed apps that need them. + +That's it! + + +Settings +======== + +Some of the application's behaviour can be configured by adding the +appropriate settings to your project's settings file. + +The following settings are available: + +FORCE_LOWERCASE_TAGS +-------------------- + +Default: ``False`` + +A boolean that turns on/off forcing of all tag names to lowercase before +they are saved to the database. + +MAX_TAG_LENGTH +-------------- + +Default: ``50`` + +An integer which specifies the maximum length which any tag is allowed +to have. This is used for validation in the ``django.contrib.admin`` +application and in any ``newforms`` forms automatically generated using +``ModelForm``. + + +Registering your models +======================= + +**New in developement version** + +Your Django models can be registered with the tagging application to +access some additional tagging-related features. + +.. note:: + + You don't *have* to register your models in order to use them with + the tagging application - many of the features added by registration + are just convenience wrappers around the tagging API provided by the + ``Tag`` and ``TaggedItem`` models and their managers, as documented + further below. + +The ``register`` function +------------------------- + +To register a model, import the ``tagging`` module and call its +``register`` function, like so:: + + from django.db import models + + import tagging + + class Widget(models.Model): + name = models.CharField(max_length=50) + + tagging.register(Widget) + +The following argument is required: + +``model`` + The model class to be registered. + + An exception will be raised if you attempt to register the same class + more than once. + +The following arguments are optional, with some recommended defaults - +take care to specify different attribute names if the defaults clash +with your model class' definition: + +``tag_descriptor_attr`` + The name of an attribute in the model class which will hold a tag + descriptor for the model. Default: ``'tags'`` + + See `TagDescriptor`_ below for details about the use of this + descriptor. + +``tagged_item_manger_attr`` + The name of an attribute in the model class which will hold a custom + manager for accessing tagged items for the model. Default: + ``'tagged'``. + + See `ModelTaggedItemManager`_ below for details about the use of this + manager. + +``TagDescriptor`` +----------------- + +When accessed through the model class itself, this descriptor will return +a ``ModelTagManager`` for the model. See `ModelTagManager`_ below for +more details about its use. + +When accessed through a model instance, this descriptor provides a handy +means of retrieving, updating and deleting the instance's tags. For +example:: + + >>> widget = Widget.objects.create(name='Testing descriptor') + >>> widget.tags + [] + >>> widget.tags = 'toast, melted cheese, butter' + >>> widget.tags + [<Tag: butter>, <Tag: melted cheese>, <Tag: toast>] + >>> del widget.tags + >>> widget.tags + [] + +``ModelTagManager`` +------------------- + +A manager for retrieving tags used by a particular model. + +Defines the following methods: + +* ``get_query_set()`` -- as this method is redefined, any ``QuerySets`` + created by this model will be initially restricted to contain the + distinct tags used by all the model's instances. + +* ``cloud(*args, **kwargs)`` -- creates a list of tags used by the + model's instances, with ``count`` and ``font_size`` attributes set for + use in displaying a tag cloud. + + See the documentation on ``Tag``'s manager's `cloud_for_model method`_ + for information on additional arguments which can be given. + +* ``related(self, tags, *args, **kwargs)`` -- creates a list of tags + used by the model's instances, which are also used by all instance + which have the given ``tags``. + + See the documentation on ``Tag``'s manager's + `related_for_model method`_ for information on additional arguments + which can be given. + +* ``usage(self, *args, **kwargs))`` -- creates a list of tags used by + the model's instances, with optional usages counts, restriction based + on usage counts and restriction of the model instances from which + usage and counts are determined. + + See the documentation on ``Tag``'s manager's `usage_for_model method`_ + for information on additional arguments which can be given. + +Example usage:: + + # Create a ``QuerySet`` of tags used by Widget instances + Widget.tags.all() + + # Retrieve a list of tags used by Widget instances with usage counts + Widget.tags.usage(counts=True) + + # Retrieve tags used by instances of WIdget which are also tagged with + # 'cheese' and 'toast' + Widget.tags.related(['cheese', 'toast'], counts=True, min_count=3) + +``ModelTaggedItemManager`` +-------------------------- + +A manager for retrieving model instance for a particular model, based on +their tags. + +* ``related_to(obj, queryset=None, num=None)`` -- creates a list + of model instances which are related to ``obj``, based on its tags. If + a ``queryset`` argument is provided, it will be used to restrict the + resulting list of model instances. + + If ``num`` is given, a maximum of ``num`` instances will be returned. + +* ``with_all(tags, queryset=None)`` -- creates a ``QuerySet`` containing + model instances which are tagged with *all* the given tags. If a + ``queryset`` argument is provided, it will be used as the basis for + the resulting ``QuerySet``. + +* ``with_any(tags, queryset=None)`` -- creates a ``QuerySet`` containing model + instances which are tagged with *any* the given tags. If a ``queryset`` + argument is provided, it will be used as the basis for the resulting + ``QuerySet``. + + +Tags +==== + +Tags are represented by the ``Tag`` model, which lives in the +``tagging.models`` module. + +API reference +------------- + +Fields +~~~~~~ + +``Tag`` objects have the following fields: + +* ``name`` -- The name of the tag. This is a unique value. + +Manager functions +~~~~~~~~~~~~~~~~~ + +The ``Tag`` model has a custom manager which has the following helper +methods: + +* ``update_tags(obj, tag_names)`` -- updates tags associated with an + object. + + ``tag_names`` is a string containing tag names with which ``obj`` + should be tagged. + + If ``tag_names`` is ``None`` or ``''``, the object's tags will be + cleared. + +* ``add_tag(obj, tag_name)`` -- associates a tag with an an object. + + ``tag_name`` is a string containing a tag name with which ``obj`` + should be tagged. + +* ``get_for_object(obj)`` -- returns a ``QuerySet`` containing all + ``Tag`` objects associated with ``obj``. + +.. _`usage_for_model method`: + +* ``usage_for_model(model, counts=False, min_count=None, filters=None)`` + -- returns a list of ``Tag`` objects associated with instances of + ``model``. + + If ``counts`` is ``True``, a ``count`` attribute will be added to each + tag, indicating how many times it has been associated with instances + of ``model``. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. Passing a value for + ``min_count`` implies ``counts=True``. + + To limit the tags (and counts, if specified) returned to those used by + a subset of the model's instances, pass a dictionary of field lookups + to be applied to ``model`` as the ``filters`` argument. + +.. _`related_for_model method`: + +* ``related_for_model(tags, Model, counts=False, min_count=None)`` + -- returns a list of tags related to a given list of tags - that is, + other tags used by items which have all the given tags. + + If ``counts`` is ``True``, a ``count`` attribute will be added to each + tag, indicating the number of items which have it in addition to the + given list of tags. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. Passing a value for + ``min_count`` implies ``counts=True``. + +.. _`cloud_for_model method`: + +* ``cloud_for_model(Model, steps=4, distribution=LOGARITHMIC, + filters=None, min_count=None)`` -- returns a list of the distinct + ``Tag`` objects associated with instances of ``Model``, each having a + ``count`` attribute as above and an additional ``font_size`` + attribute, for use in creation of a tag cloud (a type of weighted + list). + + ``steps`` defines the number of font sizes available - ``font_size`` + may 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 either + ``tagging.utils.LOGARITHMIC`` or ``tagging.utils.LINEAR``. + + To limit the tags displayed in the cloud to those associated with a + subset of the Model's instances, pass a dictionary of field lookups to + be applied to the given Model as the ``filters`` argument. + + To limit the tags displayed in the cloud to those with a ``count`` + greater than or equal to ``min_count``, pass a value for the + ``min_count`` argument. + +**New in development version** + +* ``usage_for_queryset(queryset, counts=False, min_count=None)`` -- + Obtains a list of tags associated with instances of a model contained + in the given queryset. + + If ``counts`` is True, a ``count`` attribute will be added to each tag, + indicating how many times it has been used against the Model class in + question. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. + + Passing a value for ``min_count`` implies ``counts=True``. + +Basic usage +----------- + +Tagging objects and retrieving an object's tags +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Objects may be tagged using the ``update_tags`` helper function:: + + >>> from shop.apps.products.models import Widget + >>> from tagging.models import Tag + >>> widget = Widget.objects.get(pk=1) + >>> Tag.objects.update_tags(widget, 'house thing') + +Retrieve tags for an object using the ``get_for_object`` helper +function:: + + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: thing>] + +Tags are created, associated and unassociated accordingly when you use +``update_tags`` and ``add_tags``:: + + >>> Tag.objects.update_tags(widget, 'house monkey') + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: monkey>] + >>> Tag.objects.add_tag(widget, 'tiles') + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: monkey>, <Tag: tiles>] + +Clear an object's tags by passing ``None`` or ``''`` to +``update_tags``:: + + >>> Tag.objects.update_tags(widget, None) + >>> Tag.objects.get_for_object(widget) + [] + +Retrieving tags used by a particular model +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To retrieve all tags used for a particular model, use the +``get_for_model`` helper function:: + + >>> widget1 = Widget.objects.get(pk=1) + >>> Tag.objects.update_tags(widget1, 'house thing') + >>> widget2 = Widget.objects.get(pk=2) + >>> Tag.objects.update_tags(widget2, 'cheese toast house') + >>> Tag.objects.usage_for_model(Widget) + [<Tag: cheese>, <Tag: house>, <Tag: thing>, <Tag: toast>] + +To get a count of how many times each tag was used for a particular +model, pass in ``True`` for the ``counts`` argument:: + + >>> tags = Tag.objects.usage_for_model(Widget, counts=True) + >>> [(tag.name, tag.count) for tag in tags] + [('cheese', 1), ('house', 2), ('thing', 1), ('toast', 1)] + +To get counts and limit the tags returned to those with counts above a +certain size, pass in a ``min_count`` argument:: + + >>> tags = Tag.objects.usage_for_model(Widget, min_count=2) + >>> [(tag.name, tag.count) for tag in tags] + [('house', 2)] + +You can also specify a dictionary of `field lookups`_ to be used to +restrict the tags and counts returned based on a subset of the +model's instances. For example, the following would retrieve all tags +used on Widgets created by a user named Alan which have a size +greater than 99:: + + >>> Tag.objects.usage_for_model(Widget, filters=dict(size__gt=99, user__username='Alan')) + +.. _`field lookups`: http://www.djangoproject.com/documentation/db-api/#field-lookups + +**New in development version** + +The ``usage_for_queryset`` method allows you to pass a pre-filtered +queryset to be used when determining tag usage:: + + >>> Tag.objects.usage_for_queryset(Widget.objects.filter(size__gt=99, user__username='Alan')) + +Tag input +--------- + +Tag input from users is treated as follows: + +* If the input doesn't contain any commas or double quotes, it is simply + treated as a space-delimited list of tag names. + +* If the input does contain either of these characters, we parse the + input like so: + + * Groups of characters which appear between double quotes take + precedence as multi-word tags (so double quoted tag names may + contain commas). An unclosed double quote will be ignored. + + * For the remaining input, if there are any unquoted commas in the + input, the remainder will be treated as comma-delimited. Otherwise, + it will be treated as space-delimited. + +Examples: + +====================== ======================================= ================================================ +Tag input string Resulting tags Notes +====================== ======================================= ================================================ +apple ball cat [``apple``], [``ball``], [``cat``] No commas, so space delimited +apple, ball cat [``apple``], [``ball cat``] Comma present, so comma delimited +"apple, ball" cat dog [``apple, ball``], [``cat``], [``dog``] All commas are quoted, so space delimited +"apple, ball", cat dog [``apple, ball``], [``cat dog``] Contains an unquoted comma, so comma delimited +apple "ball cat" dog [``apple``], [``ball cat``], [``dog``] No commas, so space delimited +"apple" "ball dog [``apple``], [``ball``], [``dog``] Unclosed double quote is ignored +====================== ======================================= ================================================ + + +Tagged items +============ + +The relationship between a ``Tag`` and an object is represented by +the ``TaggedItem`` model, which lives in the ``tagging.models`` +module. + +API reference +------------- + +Fields +~~~~~~ + +``TaggedItem`` objects have the following fields: + +* ``tag`` -- The ``Tag`` an object is associated with. +* ``content_type`` -- The ``ContentType`` of the associated model + instance. +* ``object_id`` -- The id of the associated object. +* ``object`` -- The associated object itself, accessible via the + Generic Relations API. + +Manager functions +~~~~~~~~~~~~~~~~~ + +The ``TaggedItem`` model has a custom manager which has the following +helper methods, which accept either a ``QuerySet`` or a ``Model`` +class as one of their arguments. To restrict the objects which are +returned, pass in a filtered ``QuerySet`` for this argument: + +* ``get_by_model(queryset_or_model, tag)`` -- creates a ``QuerySet`` + containing instances of the specififed model which are tagged with + the given tag or tags. + +* ``get_intersection_by_model(queryset_or_model, tags)`` -- creates a + ``QuerySet`` containing instances of the specified model which are + tagged with every tag in a list of tags. + + ``get_by_model`` will call this function behind the scenes when you + pass it a list, so you can use ``get_by_model`` instead of calling + this method directly. + +* ``get_union_by_model(queryset_or_model, tags)`` -- creates a + ``QuerySet`` containing instances of the specified model which are + tagged with any tag in a list of tags. + +.. _`get_related method`: + +* ``get_related(obj, queryset_or_model, num=None)`` - returns a list of + instances of the specified model which share tags with the model + instance ``obj``, ordered by the number of shared tags in descending + order. + + If ``num`` is given, a maximum of ``num`` instances will be returned. + +Basic usage +----------- + +Retrieving tagged objects +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Objects may be retrieved based on their tags using the ``get_by_model`` +manager method:: + + >>> from shop.apps.products.models import Widget + >>> from tagging.models import Tag + >>> house_tag = Tag.objects.get(name='house') + >>> TaggedItem.objects.get_by_model(Widget, house_tag) + [<Widget: pk=1>, <Widget: pk=2>] + +Passing a list of tags to ``get_by_model`` returns an intersection of +objects which have those tags, i.e. tag1 AND tag2 ... AND tagN:: + + >>> thing_tag = Tag.objects.get(name='thing') + >>> TaggedItem.objects.get_by_model(Widget, [house_tag, thing_tag]) + [<Widget: pk=1>] + +Functions which take tags are flexible when it comes to tag input:: + + >>> TaggedItem.objects.get_by_model(Widget, Tag.objects.filter(name__in=['house', 'thing'])) + [<Widget: pk=1>] + >>> TaggedItem.objects.get_by_model(Widget, 'house thing') + [<Widget: pk=1>] + >>> TaggedItem.objects.get_by_model(Widget, ['house', 'thing']) + [<Widget: pk=1>] + +Restricting objects returned +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Pass in a ``QuerySet`` to restrict the objects returned:: + + # Retrieve all Widgets which have a price less than 50, tagged with 'house' + TaggedItem.objects.get_by_model(Widget.objects.filter(price__lt=50), 'house') + + # Retrieve all Widgets which have a name starting with 'a', tagged with any + # of 'house', 'garden' or 'water'. + TaggedItem.objects.get_union_by_model(Widget.objects.filter(name__startswith='a'), + ['house', 'garden', 'water']) + + +Utilities +========= + +Tag-related utility functions are defined in the ``tagging.utils`` +module: + +``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. + +See `tag input`_ for more details. + +``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. + +``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``. + +``calculate_cloud(tags, steps=4, distribution=tagging.utils.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``. + + +Model Fields +============ + +The ``tagging.fields`` module contains fields which make it easy to +integrate tagging into your models and into the +``django.contrib.admin`` application. + +Field types +----------- + +``TagField`` +~~~~~~~~~~~~ + +A ``CharField`` that actually works as a relationship to tags "under +the hood". + +Using this example model:: + + class Link(models.Model): + ... + tags = TagField() + +Setting tags:: + + >>> l = Link.objects.get(...) + >>> l.tags = 'tag1 tag2 tag3' + +Getting tags for an instance:: + + >>> l.tags + 'tag1 tag2 tag3' + +Getting tags for a model - i.e. all tags used by all instances of the +model:: + + >>> Link.tags + 'tag1 tag2 tag3 tag4 tag5' + +This field will also validate that it has been given a valid list of +tag names, separated by a single comma, a single space or a comma +followed by a space, using the ``isTagList`` validator from +``tagging.validators``. + + +Form fields +=========== + +The ``tagging.forms`` module contains a ``Field`` for use with +Django's `newforms library`_ which takes care of validating tag name +input when used in your forms. + +.. _`newforms library`: http://www.djangoproject.com/documentation/newforms/ + +Field types +----------- + +``TagField`` +~~~~~~~~~~~~ + +A form ``Field`` which is displayed as a single-line text input, which +validates that the input it receives is a valid list of tag names. + +When you generate a form for one of your models automatically, using +the ``ModelForm`` class provided by newforms, any +``tagging.fields.TagField`` fields in your model will automatically be +represented by a ``tagging.forms.TagField`` in the generated form. + + +Generic views +============= + +The ``tagging.views`` module contains views to handle simple cases of +common display logic related to tagging. + +``tagging.views.tagged_object_list`` +------------------------------------ + +**Description:** + +A view that displays a list of objects for a given model which have a +given tag. This is a thin wrapper around the +``django.views.generic.list_detail.object_list`` view, which takes a +model and a tag as its arguments (in addition to the other optional +arguments supported by ``object_list``), building the appropriate +``QuerySet`` for you instead of expecting one to be passed in. + +**Required arguments:** + + * ``queryset_or_model``: A ``QuerySet`` or Django model class for the + object which will be listed. + + * ``tag``: The tag which objects of the given model must have in + order to be listed. + +**Optional arguments:** + +Please refer to the `object_list documentation`_ for additional optional +arguments which may be given. + + * ``related_tags``: If ``True``, a ``related_tags`` context variable + will also contain tags related to the given tag for the given + model. + + * ``related_tag_counts``: If ``True`` and ``related_tags`` is + ``True``, each related tag will have a ``count`` attribute + indicating the number of items which have it in addition to the + given tag. + +**Template context:** + +Please refer to the `object_list documentation`_ for additional +template context variables which may be provided. + + * ``tag``: The ``Tag`` instance for the given tag. + +.. _`object_list documentation`: http://www.djangoproject.com/documentation/generic_views/#django-views-generic-list-detail-object-list + +Example usage +~~~~~~~~~~~~~ + +The following sample URLconf demonstrates using this generic view to +list items of a particular model class which have a given tag:: + + from django.conf.urls.defaults import * + + from tagging.views import tagged_object_list + + from shop.apps.products.models import Widget + + urlpatterns = patterns('', + url(r'^widgets/tag/(?P<tag>[^/]+)/$', + tagged_object_list, + dict(model=Widget, paginate_by=10, allow_empty=True, + template_object_name='widget'), + name='widget_tag_detail'), + ) + +The following sample view demonstrates wrapping this generic view to +perform filtering of the objects which are listed:: + + from myapp.models import People + + from tagging.views import tagged_object_list + + def tagged_people(request, country_code, tag): + queryset = People.objects.filter(country__code=country_code) + return tagged_object_list(request, queryset, tag, paginate_by=25, + allow_empty=True, template_object_name='people') + + +Template tags +============= + +The ``tagging.templatetags.tagging_tags`` module defines a number of +template tags which may be used to work with tags. + +Tag reference +------------- + +tags_for_model +~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects associated with a given model and +stores them in a context variable. + +Usage:: + + {% tags_for_model [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +Extended usage:: + + {% tags_for_model [model] as [varname] with counts %} + +If specified - by providing extra ``with counts`` arguments - adds a +``count`` attribute to each tag containing the number of instances of +the given model which have been tagged with it. + +Examples:: + + {% tags_for_model products.Widget as widget_tags %} + {% tags_for_model products.Widget as widget_tags with counts %} + +tag_cloud_for_model +~~~~~~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects for a given model, with tag cloud +attributes set, and stores them in a context variable. + +Usage:: + + {% tag_cloud_for_model [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +Extended usage:: + + {% tag_cloud_for_model [model] as [varname] with [options] %} + +Extra options can be provided after an optional ``with`` argument, with +each option being specified in ``[name]=[value]`` format. Valid extra +options are: + + ``steps`` + Integer. Defines the range of font sizes. + + ``min_count`` + Integer. Defines the minimum number of times a tag must have + been used to appear in the cloud. + + ``distribution`` + One of ``linear`` or ``log``. Defines the font-size + distribution algorithm to use when generating the tag cloud. + +Examples:: + + {% tag_cloud_for_model products.Widget as widget_tags %} + {% tag_cloud_for_model products.Widget as widget_tags with steps=9 min_count=3 distribution=log %} + +tags_for_object +~~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects associated with an object and stores +them in a context variable. + +Usage:: + + {% tags_for_object [object] as [varname] %} + +Example:: + + {% tags_for_object foo_object as tag_list %} + +tagged_objects +~~~~~~~~~~~~~~ + +Retrieves a list of instances of a given model which are tagged with a +given ``Tag`` and stores them in a context variable. + +Usage:: + + {% tagged_objects [tag] in [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +The tag must be an instance of a ``Tag``, not the name of a tag. + +Example:: + + {% tagged_objects comedy_tag in tv.Show as comedies %} diff --git a/docs/overview.txt b/docs/overview.txt index c5c72e6..9641f03 100644 --- a/docs/overview.txt +++ b/docs/overview.txt @@ -1,751 +1,912 @@ -==============
-Django Tagging
-==============
-
-A generic tagging application for `Django`_ projects, which allows
-association of a number of tags with any Django model instance and makes
-retrieval of tags simple.
-
-.. _`Django`: http://www.djangoproject.com
-
-.. contents::
- :depth: 3
-
-
-Installation
-============
-
-Installing an official release
-------------------------------
-
-Official releases are made available from
-http://code.google.com/p/django-tagging/
-
-Source distribution
-~~~~~~~~~~~~~~~~~~~
-
-Download the .zip distribution file and unpack it. Inside is a script
-named ``setup.py``. Enter this command::
-
- python setup.py install
-
-...and the package will install automatically.
-
-Windows installer
-~~~~~~~~~~~~~~~~~
-
-A Windows installer is also made available - download the .exe
-distribution file and launch it to install the application.
-
-An uninstaller will also be created, accessible through Add/Remove
-Programs in your Control Panel.
-
-Installing the development version
-----------------------------------
-
-Alternatively, if you'd like to update Django Tagging occasionally to pick
-up the latest bug fixes and enhancements before they make it into an
-offical release, perform a `Subversion`_ checkout instead. The following
-command will check the application's development branch out to an
-``mptt-trunk`` directory::
-
- svn checkout http://django-tagging.googlecode.com/svn/trunk/ tagging-trunk
-
-Add the resulting folder to your `PYTHONPATH`_ or symlink (`junction`_,
-if you're on Windows) the ``tagging`` directory inside it into a
-directory which is on your PYTHONPATH, such as your Python
-installation's ``site-packages`` directory.
-
-You can verify that the application is available on your PYTHONPATH by
-opening a Python interpreter and entering the following commands::
-
- >>> import tagging
- >>> tagging.VERSION
- (0, 2, 'pre')
-
-When you want to update your copy of the Django Tagging source code, run
-the command ``svn update`` from within the ``tagging-trunk`` directory.
-
-.. caution::
-
- The development version may contain bugs which are not present in the
- release version and introduce backwards-incompatible changes.
-
- If you're tracking trunk, keep an eye on the `CHANGELOG`_ and the
- `backwards-incompatible changes wiki page`_ before you update your
- copy of the source code.
-
-.. _`Subversion`: http://subversion.tigris.org
-.. _`PYTHONPATH`: http://docs.python.org/tut/node8.html#SECTION008110000000000000000
-.. _`junction`: http://www.microsoft.com/technet/sysinternals/FileAndDisk/Junction.mspx
-.. _`CHANGELOG`: http://django-tagging.googlecode.com/svn/trunk/CHANGELOG.txt
-.. _`backwards-incompatible changes wiki page`: http://code.google.com/p/django-tagging/wiki/BackwardsIncompatibleChanges
-
-Using Django Tagging in your applications
------------------------------------------
-
-Once you've installed Django Tagging and want to use it in your Django
-applications, do the following:
-
- 1. Put ``'tagging'`` in your ``INSTALLED_APPS`` setting.
- 2. Run the command ``manage.py syncdb``.
-
-The ``syncdb`` command creates the necessary database tables and
-creates permission objects for all installed apps that need them.
-
-That's it!
-
-
-Settings
-========
-
-Some of Django Tagging's behaviour may be configured by adding the
-appropriate settings to your project's settings file.
-
-The following settings are available:
-
-FORCE_LOWERCASE_TAGS
---------------------
-
-Default: ``False``
-
-A boolean that turns on/off forcing of all tag names to lowercase before
-they are saved to the database.
-
-MAX_TAG_LENGTH
---------------
-
-Default: ``50``
-
-An integer which specifies the maxiumum length which any tag is allowed
-to have. This is used for validation in the ``django.contrib.admin``
-application and in any ``newforms`` forms automatically generated using
-``ModelForm``.
-
-
-Tags
-====
-
-Tags are represented by the ``Tag`` model, which lives in the
-``tagging.models`` module.
-
-API reference
--------------
-
-Fields
-~~~~~~
-
-``Tag`` objects have the following fields:
-
- * ``name`` -- The name of the tag. This is a unique value.
-
-Manager functions
-~~~~~~~~~~~~~~~~~
-
-The ``Tag`` model has a custom manager which has the following helper
-functions:
-
- * ``update_tags(obj, tag_names)`` -- updates tags associated with an
- object.
-
- ``tag_names`` is a string containing tag names with which ``obj``
- should be tagged.
-
- If ``tag_names`` is ``None`` or ``''``, the object's tags will be
- cleared.
-
- * ``add_tag(obj, tag_name)`` -- associates a tag with an an object.
-
- ``tag_name`` is a string containing a tag name with which ``obj``
- should be tagged.
-
- * ``get_for_object(obj)`` -- returns a ``QuerySet`` containing all
- ``Tag`` objects associated with ``obj``.
-
- * ``usage_for_model(Model, counts=False, min_count=None, filters=None)``
- -- returns a list of ``Tag`` objects associated with instances of
- ``Model``.
-
- If ``counts`` is ``True``, a ``count`` attribute will be added to
- each tag, indicating how many times it has been associated with
- instances of ``Model``.
-
- If ``min_count`` is given, only tags which have a ``count`` greater
- than or equal to ``min_count`` will be returned. Passing a value
- for ``min_count`` implies ``counts=True``.
-
- To limit the tags (and counts, if specified) returned to those used
- by a subset of the model's instances, pass a dictionary of field
- lookups to be applied to ``Model`` as the ``filters`` argument.
-
- * ``related_for_model(tags, Model, counts=False, min_count=None)``
- -- returns a list of tags related to a given list of tags - that
- is, other tags used by items which have all the given tags.
-
- If ``counts`` is ``True``, a ``count`` attribute will be added to
- each tag, indicating the number of items which have it in addition
- to the given list of tags.
-
- If ``min_count`` is given, only tags which have a ``count`` greater
- than or equal to ``min_count`` will be returned. Passing a value
- for ``min_count`` implies ``counts=True``.
-
- * ``cloud_for_model(Model, steps=4, distribution=LOGARITHMIC,
- filters=None, min_count=None)`` -- returns a list of the
- distinct ``Tag`` objects associated with instances of ``Model``,
- each having a ``count`` attribute as above and an additional
- ``font_size`` attribute, for use in creation of a tag cloud (a
- type of weighted list).
-
- ``steps`` defines the number of font sizes available -
- ``font_size`` may 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
- either ``tagging.utils.LOGARITHMIC`` or ``tagging.utils.LINEAR``.
-
- To limit the tags displayed in the cloud to those associated
- with a subset of the Model's instances, pass a dictionary of
- field lookups to be applied to the given Model as the ``filters``
- argument.
-
- To limit the tags displayed in the cloud to those with a ``count``
- greater than or equal to ``min_count``, pass a value for the
- ``min_count`` argument.
-
-Basic usage
------------
-
-Tag input
-~~~~~~~~~
-
-Tag input from users is treated as follows:
-
-* If the tag input doesn't contain any commas or double quotes, it is
- simply treated as a space-delimited list of tag names.
-
-* If the tag input does contain either of these characters, we parse the
- input like so:
-
- * Groups of characters which appear between double quotes take
- precedence as multi-word tags (so double quoted tag names may
- contain commas). An unclosed double quote will be ignored.
-
- * For the remaining input, if there are any unquoted commas in the
- input, the remainder will be treated as comma-delimited.
- Otherwise, it will be treated as space-delimited.
-
-Examples:
-
-====================== ======================================= ================================================
-Tag input Resulting tag names Notes
-====================== ======================================= ================================================
-apple ball cat [``apple``], [``ball``], [``cat``] No commas or quotes, so space delimited
-apple, ball cat [``apple``], [``ball cat``] Comma present, so comma delimited
-"apple, ball" cat dog [``apple, ball``], [``cat``], [``dog``] All commas are quoted, so space delimited
-"apple, ball", cat dog [``apple, ball``], [``cat dog``] Contains an unquoted comma, so comma delimited
-apple "ball cat" dog [``apple``], [``ball cat``], [``dog``] No commas, so space delimited
-"apple" "ball dog [``apple``], [``ball``], [``dog``] Unclosed double quote is ignored
-====================== ======================================= ================================================
-
-Tagging objects and retrieving an object's tags
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Objects may be tagged using the ``update_tags`` helper function::
-
- >>> from shop.apps.products.models import Widget
- >>> from tagging.models import Tag
- >>> widget = Widget.objects.get(pk=1)
- >>> Tag.objects.update_tags(widget, 'house thing')
-
-Retrieve tags for an object using the ``get_for_object`` helper
-function::
-
- >>> Tag.objects.get_for_object(widget)
- [<Tag: house>, <Tag: thing>]
-
-Tags are created, associated and unassociated accordingly when you use
-``update_tags`` and ``add_tags``::
-
- >>> Tag.objects.update_tags(widget, 'house monkey')
- >>> Tag.objects.get_for_object(widget)
- [<Tag: house>, <Tag: monkey>]
- >>> Tag.objects.add_tag(widget, 'tiles')
- >>> Tag.objects.get_for_object(widget)
- [<Tag: house>, <Tag: monkey>, <Tag: tiles>]
-
-Clear an object's tags by passing ``None`` or ``''`` to
-``update_tags``::
-
- >>> Tag.objects.update_tags(widget, None)
- >>> Tag.objects.get_for_object(widget)
- []
-
-Retrieving tags used by a particular model
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-To retrieve all tags used for a particular model, use the
-``get_for_model`` helper function::
-
- >>> widget1 = Widget.objects.get(pk=1)
- >>> Tag.objects.update_tags(widget1, 'house thing')
- >>> widget2 = Widget.objects.get(pk=2)
- >>> Tag.objects.update_tags(widget2, 'cheese toast house')
- >>> Tag.objects.usage_for_model(Widget)
- [<Tag: cheese>, <Tag: house>, <Tag: thing>, <Tag: toast>]
-
-To get a count of how many times each tag was used for a particular
-model, pass in ``True`` for the ``counts`` argument::
-
- >>> tags = Tag.objects.usage_for_model(Widget, counts=True)
- >>> [(tag.name, tag.count) for tag in tags]
- [('cheese', 1), ('house', 2), ('thing', 1), ('toast', 1)]
-
-To get counts and limit the tags returned to those with counts above a
-certain size, pass in a ``min_count`` argument::
-
- >>> tags = Tag.objects.usage_for_model(Widget, min_count=2)
- >>> [(tag.name, tag.count) for tag in tags]
- [('house', 2)]
-
-You can also specify a dictionary of `field lookups`_ to be used to
-restrict the tags and counts returned based on a subset of the
-model's instances. For example, the following would retrieve all tags
-used on Widgets created by a user named Alan which have a size
-greater than 99::
-
- >>> Tag.objects.usage_for_model(Widget, filters=dict(size__gt=99, user__username='Alan'))
-
-.. _`field lookups`: http://www.djangoproject.com/documentation/db-api/#field-lookups
-
-
-Tagged items
-============
-
-The relationship between a ``Tag`` and an object is represented by
-the ``TaggedItem`` model, which lives in the ``tagging.models``
-module.
-
-API reference
--------------
-
-Fields
-~~~~~~
-
-``TaggedItem`` objects have the following fields:
-
- * ``tag`` -- The ``Tag`` an object is associated with.
- * ``content_type`` -- The ``ContentType`` of the associated model
- instance.
- * ``object_id`` -- The id of the associated object.
- * ``object`` -- The associated object itself, accessible via the
- Generic Relations API.
-
-Manager functions
-~~~~~~~~~~~~~~~~~
-
-The ``TaggedItem`` model has a custom manager which has the following
-helper functions:
-
- * ``get_by_model(Model, tag)`` -- If ``tag`` is an instance of a
- ``Tag``, returns a ``QuerySet`` containing all instances of
- ``Model`` which are tagged with it.
-
- If ``tag`` is a list of tags, returns a ``QuerySet`` containing
- all instances of ``Model`` which are tagged with every tag in
- the list.
-
- * ``get_intersection_by_model(Model, tags)`` -- Returns a
- ``QuerySet`` containing all instances of ``Model`` which are
- tagged with every tag in the list.
-
- ``get_by_model`` will call this function behind the scenes when
- you pass it a list, so it's recommended that you use
- ``get_by_model`` instead of calling this function directly.
-
- * ``get_union_by_model(Model, tags)`` -- Returns a ``QuerySet``
- containing all instances of ``Model`` which are tagged with any tag
- in the list.
-
- * ``get_related(obj, Model, num=None)`` - Returns instances of
- ``Model`` which share tags with the model instance ``obj``,
- ordered by the number of shared tags in descending order.
-
- If ``num`` is given, a maximum of ``num`` instances will be
- returned.
-
-Basic usage
------------
-
-Retrieving tagged objects
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Objects may be retrieved based on their tags using the ``get_by_model``
-manager method::
-
- >>> from shop.apps.products.models import Widget
- >>> from tagging.models import Tag
- >>> house_tag = Tag.objects.get(name='house')
- >>> TaggedItem.objects.get_by_model(Widget, house_tag)
- [<Widget: pk=1>, <Widget: pk=2>]
-
-Passing a list of tags to ``get_by_model`` returns an intersection of
-objects which have those tags, i.e. tag1 AND tag2 ... AND tagN::
-
- >>> thing_tag = Tag.objects.get(name='thing')
- >>> TaggedItem.objects.get_by_model(Widget, [house_tag, thing_tag])
- [<Widget: pk=1>]
-
-Functions which take tags are flexible when it comes to tag input::
-
- >>> TaggedItem.objects.get_by_model(Widget, Tag.objects.filter(name__in=['house', 'thing']))
- [<Widget: pk=1>]
- >>> TaggedItem.objects.get_by_model(Widget, 'house thing')
- [<Widget: pk=1>]
- >>> TaggedItem.objects.get_by_model(Widget, ['house', 'thing'])
- [<Widget: pk=1>]
-
-
-Utilities
-=========
-
-Tag-related utility functions are defined in the ``tagging.utils``
-module:
-
-``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.
-
-See `tag input`_ for more details.
-
-``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.
-
-``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``.
-
-``calculate_cloud(tags, steps=4, distribution=tagging.utils.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``.
-
-
-Model Fields
-============
-
-The ``tagging.fields`` module contains fields which make it easy to
-integrate tagging into your models and into the
-``django.contrib.admin`` application.
-
-Field types
------------
-
-``TagField``
-~~~~~~~~~~~~
-
-A ``CharField`` that actually works as a relationship to tags "under
-the hood".
-
-Using this example model::
-
- class Link(models.Model):
- ...
- tags = TagField()
-
-Setting tags::
-
- >>> l = Link.objects.get(...)
- >>> l.tags = 'tag1 tag2 tag3'
-
-Getting tags for an instance::
-
- >>> l.tags
- 'tag1 tag2 tag3'
-
-Getting tags for a model - i.e. all tags used by all instances of the
-model::
-
- >>> Link.tags
- 'tag1 tag2 tag3 tag4 tag5'
-
-This field will also validate that it has been given a valid list of
-tag names, separated by a single comma, a single space or a comma
-followed by a space, using the ``isTagList`` validator from
-``tagging.validators``.
-
-
-Form fields
-===========
-
-The ``tagging.forms`` module contains a ``Field`` for use with
-Django's `newforms library`_ which takes care of validating tag name
-input when used in your forms.
-
-.. _`newforms library`: http://www.djangoproject.com/documentation/newforms/
-
-Field types
------------
-
-``TagField``
-~~~~~~~~~~~~
-
-A form ``Field`` which is displayed as a single-line text input, which
-validates that the input it receives is a valid list of tag names.
-
-When you generate a form for one of your models automatically, using
-the ``ModelForm`` class provided by newforms, any
-``tagging.fields.TagField`` fields in your model will automatically be
-represented by a ``tagging.forms.TagField`` in the generated form.
-
-
-Simplified tagging and retrieval of tags with properties
-========================================================
-
-If you're not using ``TagField``, a useful method for simplifying
-tagging and retrieval of tags for your models is to set up a
-property::
-
- from django.db import models
- from tagging.models import Tag
-
- class MyModel(models.Model):
- name = models.CharField(maxlength=100)
- tag_list = models.CharField(maxlength=255)
-
- def save(self):
- super(MyModel, self).save()
- self.tags = self.tag_list
-
- def _get_tags(self):
- return Tag.objects.get_for_object(self)
-
- def _set_tags(self, tag_list):
- Tag.objects.update_tags(self, tag_list)
-
- tags = property(_get_tags, _set_tags)
-
- def __unicode__(self):
- return self.name
-
-Once you've set this up, you can access and set tags in a fairly
-natural way::
-
- >>> obj = MyModel.objects.get(pk=1)
- >>> obj.tags = 'foo bar'
- >>> obj.tags
- [<Tag: bar>, <Tag: foo>]
-
-Remember that ``obj.tags`` will return a ``QuerySet``, so you can
-perform further filtering on it, should you need to.
-
-
-Generic views
-=============
-
-The ``tagging.views`` module contains views to handle simple cases of
-common display logic related to tagging.
-
-``tagging.views.tagged_object_list``
-------------------------------------
-
-**Description:**
-
-A view that displays a list of objects for a given model which have a
-given tag. This is a thin wrapper around the
-``django.views.generic.list_detail.object_list`` view, which takes a
-model and a tag as its arguments (in addition to the other optional
-arguments supported by ``object_list``), building the appropriate
-``QuerySet`` for you instead of expecting one to be passed in.
-
-**Required arguments:**
-
- * ``model``: The Django model class of the object that will be
- listed.
-
- * ``tag``: The tag which objects of the given model must have in
- order to be listed.
-
-**Optional arguments:**
-
-Please refer to the `object_list documentation`_ for additional optional
-arguments which may be given.
-
- * ``related_tags``: If ``True``, a ``related_tags`` context variable
- will also contain tags related to the given tag for the given
- model.
-
- * ``related_tag_counts``: If ``True`` and ``related_tags`` is
- ``True``, each related tag will have a ``count`` attribute
- indicating the number of items which have it in addition to the
- given tag.
-
-**Template context:**
-
-Please refer to the `object_list documentation`_ for additional
-template context variables which may be provided.
-
- * ``tag``: The ``Tag`` instance for the given tag.
-
-.. _`object_list documentation`: http://www.djangoproject.com/documentation/generic_views/#django-views-generic-list-detail-object-list
-
-Example usage
-~~~~~~~~~~~~~
-
-The following sample URLconf demonstrates using this generic view to
-list items of a particular model class which have a given tag::
-
- from django.conf.urls.defaults import *
- from tagging.views import tagged_object_list
- from shop.apps.products.models import Widget
-
- urlpatterns = patterns('',
- url(r'^widgets/tag/(?P<tag>[^/]+)/$',
- tagged_object_list,
- dict(model=Widget, paginate_by=10, allow_empty=True,
- template_object_name='widget'),
- name='widget_tag_detail'),
- )
-
-
-Template tags
-=============
-
-The ``tagging.templatetags.tagging_tags`` module defines a number of
-template tags which may be used to work with tags.
-
-Tag reference
--------------
-
-tags_for_model
-~~~~~~~~~~~~~~
-
-Retrieves a list of ``Tag`` objects associated with a given model and
-stores them in a context variable.
-
-Usage::
-
- {% tags_for_model [model] as [varname] %}
-
-The model is specified in ``[appname].[modelname]`` format.
-
-Extended usage::
-
- {% tags_for_model [model] as [varname] with counts %}
-
-If specified - by providing extra ``with counts`` arguments - adds a
-``count`` attribute to each tag containing the number of instances of
-the given model which have been tagged with it.
-
-Examples::
-
- {% tags_for_model products.Widget as widget_tags %}
- {% tags_for_model products.Widget as widget_tags with counts %}
-
-tag_cloud_for_model
-~~~~~~~~~~~~~~~~~~~
-
-Retrieves a list of ``Tag`` objects for a given model, with tag cloud
-attributes set, and stores them in a context variable.
-
-Usage::
-
- {% tag_cloud_for_model [model] as [varname] %}
-
-The model is specified in ``[appname].[modelname]`` format.
-
-Extended usage::
-
- {% tag_cloud_for_model [model] as [varname] with [options] %}
-
-Extra options can be provided after an optional ``with`` argument, with
-each option being specified in ``[name]=[value]`` format. Valid extra
-options are:
-
- ``steps``
- Integer. Defines the range of font sizes.
-
- ``min_count``
- Integer. Defines the minimum number of times a tag must have
- been used to appear in the cloud.
-
- ``distribution``
- One of ``linear`` or ``log``. Defines the font-size
- distribution algorithm to use when generating the tag cloud.
-
-Examples::
-
- {% tag_cloud_for_model products.Widget as widget_tags %}
- {% tag_cloud_for_model products.Widget as widget_tags with steps=9 min_count=3 distribution=log %}
-
-tags_for_object
-~~~~~~~~~~~~~~~
-
-Retrieves a list of ``Tag`` objects associated with an object and stores
-them in a context variable.
-
-Usage::
-
- {% tags_for_object [object] as [varname] %}
-
-Example::
-
- {% tags_for_object foo_object as tag_list %}
-
-tagged_objects
-~~~~~~~~~~~~~~
-
-Retrieves a list of instances of a given model which are tagged with a
-given ``Tag`` and stores them in a context variable.
-
-Usage::
-
- {% tagged_objects [tag] in [model] as [varname] %}
-
-The model is specified in ``[appname].[modelname]`` format.
-
-The tag must be an instance of a ``Tag``, not the name of a tag.
-
-Example::
-
- {% tagged_objects comedy_tag in tv.Show as comedies %}
+============== +Django Tagging +============== + +A generic tagging application for `Django`_ projects, which allows +association of a number of tags with any Django model instance and makes +retrieval of tags simple. + +.. _`Django`: http://www.djangoproject.com + +.. contents:: + :depth: 3 + + +Installation +============ + +Installing an official release +------------------------------ + +Official releases are made available from +http://code.google.com/p/django-tagging/ + +Source distribution +~~~~~~~~~~~~~~~~~~~ + +Download the .zip distribution file and unpack it. Inside is a script +named ``setup.py``. Enter this command:: + + python setup.py install + +...and the package will install automatically. + +Windows installer +~~~~~~~~~~~~~~~~~ + +A Windows installer is also made available - download the .exe +distribution file and launch it to install the application. + +An uninstaller will also be created, accessible through Add/Remove +Programs in your Control Panel. + +Installing the development version +---------------------------------- + +Alternatively, if you'd like to update Django Tagging occasionally to pick +up the latest bug fixes and enhancements before they make it into an +official release, perform a `Subversion`_ checkout instead. The following +command will check the application's development branch out to an +``tagging-trunk`` directory:: + + svn checkout http://django-tagging.googlecode.com/svn/trunk/ tagging-trunk + +Add the resulting folder to your `PYTHONPATH`_ or symlink (`junction`_, +if you're on Windows) the ``tagging`` directory inside it into a +directory which is on your PYTHONPATH, such as your Python +installation's ``site-packages`` directory. + +You can verify that the application is available on your PYTHONPATH by +opening a Python interpreter and entering the following commands:: + + >>> import tagging + >>> tagging.VERSION + (0, 3, 'pre') + +When you want to update your copy of the Django Tagging source code, run +the command ``svn update`` from within the ``tagging-trunk`` directory. + +.. caution:: + + The development version may contain bugs which are not present in the + release version and introduce backwards-incompatible changes. + + If you're tracking trunk, keep an eye on the `CHANGELOG`_ and the + `backwards-incompatible changes wiki page`_ before you update your + copy of the source code. + +.. _`Subversion`: http://subversion.tigris.org +.. _`PYTHONPATH`: http://docs.python.org/tut/node8.html#SECTION008110000000000000000 +.. _`junction`: http://www.microsoft.com/technet/sysinternals/FileAndDisk/Junction.mspx +.. _`CHANGELOG`: http://django-tagging.googlecode.com/svn/trunk/CHANGELOG.txt +.. _`backwards-incompatible changes wiki page`: http://code.google.com/p/django-tagging/wiki/BackwardsIncompatibleChanges + +Using Django Tagging in your applications +----------------------------------------- + +Once you've installed Django Tagging and want to use it in your Django +applications, do the following: + + 1. Put ``'tagging'`` in your ``INSTALLED_APPS`` setting. + 2. Run the command ``manage.py syncdb``. + +The ``syncdb`` command creates the necessary database tables and +creates permission objects for all installed apps that need them. + +That's it! + + +Settings +======== + +Some of the application's behaviour can be configured by adding the +appropriate settings to your project's settings file. + +The following settings are available: + +FORCE_LOWERCASE_TAGS +-------------------- + +Default: ``False`` + +A boolean that turns on/off forcing of all tag names to lowercase before +they are saved to the database. + +MAX_TAG_LENGTH +-------------- + +Default: ``50`` + +An integer which specifies the maximum length which any tag is allowed +to have. This is used for validation in the ``django.contrib.admin`` +application and in any ``newforms`` forms automatically generated using +``ModelForm``. + + +Registering your models +======================= + +**New in developement version** + +Your Django models can be registered with the tagging application to +access some additional tagging-related features. + +.. note:: + + You don't *have* to register your models in order to use them with + the tagging application - many of the features added by registration + are just convenience wrappers around the tagging API provided by the + ``Tag`` and ``TaggedItem`` models and their managers, as documented + further below. + +The ``register`` function +------------------------- + +To register a model, import the ``tagging`` module and call its +``register`` function, like so:: + + from django.db import models + + import tagging + + class Widget(models.Model): + name = models.CharField(max_length=50) + + tagging.register(Widget) + +The following argument is required: + +``model`` + The model class to be registered. + + An exception will be raised if you attempt to register the same class + more than once. + +The following arguments are optional, with some recommended defaults - +take care to specify different attribute names if the defaults clash +with your model class' definition: + +``tag_descriptor_attr`` + The name of an attribute in the model class which will hold a tag + descriptor for the model. Default: ``'tags'`` + + See `TagDescriptor`_ below for details about the use of this + descriptor. + +``tagged_item_manger_attr`` + The name of an attribute in the model class which will hold a custom + manager for accessing tagged items for the model. Default: + ``'tagged'``. + + See `ModelTaggedItemManager`_ below for details about the use of this + manager. + +``TagDescriptor`` +----------------- + +When accessed through the model class itself, this descriptor will return +a ``ModelTagManager`` for the model. See `ModelTagManager`_ below for +more details about its use. + +When accessed through a model instance, this descriptor provides a handy +means of retrieving, updating and deleting the instance's tags. For +example:: + + >>> widget = Widget.objects.create(name='Testing descriptor') + >>> widget.tags + [] + >>> widget.tags = 'toast, melted cheese, butter' + >>> widget.tags + [<Tag: butter>, <Tag: melted cheese>, <Tag: toast>] + >>> del widget.tags + >>> widget.tags + [] + +``ModelTagManager`` +------------------- + +A manager for retrieving tags used by a particular model. + +Defines the following methods: + +* ``get_query_set()`` -- as this method is redefined, any ``QuerySets`` + created by this model will be initially restricted to contain the + distinct tags used by all the model's instances. + +* ``cloud(*args, **kwargs)`` -- creates a list of tags used by the + model's instances, with ``count`` and ``font_size`` attributes set for + use in displaying a tag cloud. + + See the documentation on ``Tag``'s manager's `cloud_for_model method`_ + for information on additional arguments which can be given. + +* ``related(self, tags, *args, **kwargs)`` -- creates a list of tags + used by the model's instances, which are also used by all instance + which have the given ``tags``. + + See the documentation on ``Tag``'s manager's + `related_for_model method`_ for information on additional arguments + which can be given. + +* ``usage(self, *args, **kwargs))`` -- creates a list of tags used by + the model's instances, with optional usages counts, restriction based + on usage counts and restriction of the model instances from which + usage and counts are determined. + + See the documentation on ``Tag``'s manager's `usage_for_model method`_ + for information on additional arguments which can be given. + +Example usage:: + + # Create a ``QuerySet`` of tags used by Widget instances + Widget.tags.all() + + # Retrieve a list of tags used by Widget instances with usage counts + Widget.tags.usage(counts=True) + + # Retrieve tags used by instances of WIdget which are also tagged with + # 'cheese' and 'toast' + Widget.tags.related(['cheese', 'toast'], counts=True, min_count=3) + +``ModelTaggedItemManager`` +-------------------------- + +A manager for retrieving model instance for a particular model, based on +their tags. + +* ``related_to(obj, queryset=None, num=None)`` -- creates a list + of model instances which are related to ``obj``, based on its tags. If + a ``queryset`` argument is provided, it will be used to restrict the + resulting list of model instances. + + If ``num`` is given, a maximum of ``num`` instances will be returned. + +* ``with_all(tags, queryset=None)`` -- creates a ``QuerySet`` containing + model instances which are tagged with *all* the given tags. If a + ``queryset`` argument is provided, it will be used as the basis for + the resulting ``QuerySet``. + +* ``with_any(tags, queryset=None)`` -- creates a ``QuerySet`` containing model + instances which are tagged with *any* the given tags. If a ``queryset`` + argument is provided, it will be used as the basis for the resulting + ``QuerySet``. + + +Tags +==== + +Tags are represented by the ``Tag`` model, which lives in the +``tagging.models`` module. + +API reference +------------- + +Fields +~~~~~~ + +``Tag`` objects have the following fields: + +* ``name`` -- The name of the tag. This is a unique value. + +Manager functions +~~~~~~~~~~~~~~~~~ + +The ``Tag`` model has a custom manager which has the following helper +methods: + +* ``update_tags(obj, tag_names)`` -- updates tags associated with an + object. + + ``tag_names`` is a string containing tag names with which ``obj`` + should be tagged. + + If ``tag_names`` is ``None`` or ``''``, the object's tags will be + cleared. + +* ``add_tag(obj, tag_name)`` -- associates a tag with an an object. + + ``tag_name`` is a string containing a tag name with which ``obj`` + should be tagged. + +* ``get_for_object(obj)`` -- returns a ``QuerySet`` containing all + ``Tag`` objects associated with ``obj``. + +.. _`usage_for_model method`: + +* ``usage_for_model(model, counts=False, min_count=None, filters=None)`` + -- returns a list of ``Tag`` objects associated with instances of + ``model``. + + If ``counts`` is ``True``, a ``count`` attribute will be added to each + tag, indicating how many times it has been associated with instances + of ``model``. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. Passing a value for + ``min_count`` implies ``counts=True``. + + To limit the tags (and counts, if specified) returned to those used by + a subset of the model's instances, pass a dictionary of field lookups + to be applied to ``model`` as the ``filters`` argument. + +.. _`related_for_model method`: + +* ``related_for_model(tags, Model, counts=False, min_count=None)`` + -- returns a list of tags related to a given list of tags - that is, + other tags used by items which have all the given tags. + + If ``counts`` is ``True``, a ``count`` attribute will be added to each + tag, indicating the number of items which have it in addition to the + given list of tags. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. Passing a value for + ``min_count`` implies ``counts=True``. + +.. _`cloud_for_model method`: + +* ``cloud_for_model(Model, steps=4, distribution=LOGARITHMIC, + filters=None, min_count=None)`` -- returns a list of the distinct + ``Tag`` objects associated with instances of ``Model``, each having a + ``count`` attribute as above and an additional ``font_size`` + attribute, for use in creation of a tag cloud (a type of weighted + list). + + ``steps`` defines the number of font sizes available - ``font_size`` + may 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 either + ``tagging.utils.LOGARITHMIC`` or ``tagging.utils.LINEAR``. + + To limit the tags displayed in the cloud to those associated with a + subset of the Model's instances, pass a dictionary of field lookups to + be applied to the given Model as the ``filters`` argument. + + To limit the tags displayed in the cloud to those with a ``count`` + greater than or equal to ``min_count``, pass a value for the + ``min_count`` argument. + +**New in development version** + +* ``usage_for_queryset(queryset, counts=False, min_count=None)`` -- + Obtains a list of tags associated with instances of a model contained + in the given queryset. + + If ``counts`` is True, a ``count`` attribute will be added to each tag, + indicating how many times it has been used against the Model class in + question. + + If ``min_count`` is given, only tags which have a ``count`` greater + than or equal to ``min_count`` will be returned. + + Passing a value for ``min_count`` implies ``counts=True``. + +Basic usage +----------- + +Tagging objects and retrieving an object's tags +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Objects may be tagged using the ``update_tags`` helper function:: + + >>> from shop.apps.products.models import Widget + >>> from tagging.models import Tag + >>> widget = Widget.objects.get(pk=1) + >>> Tag.objects.update_tags(widget, 'house thing') + +Retrieve tags for an object using the ``get_for_object`` helper +function:: + + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: thing>] + +Tags are created, associated and unassociated accordingly when you use +``update_tags`` and ``add_tags``:: + + >>> Tag.objects.update_tags(widget, 'house monkey') + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: monkey>] + >>> Tag.objects.add_tag(widget, 'tiles') + >>> Tag.objects.get_for_object(widget) + [<Tag: house>, <Tag: monkey>, <Tag: tiles>] + +Clear an object's tags by passing ``None`` or ``''`` to +``update_tags``:: + + >>> Tag.objects.update_tags(widget, None) + >>> Tag.objects.get_for_object(widget) + [] + +Retrieving tags used by a particular model +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To retrieve all tags used for a particular model, use the +``get_for_model`` helper function:: + + >>> widget1 = Widget.objects.get(pk=1) + >>> Tag.objects.update_tags(widget1, 'house thing') + >>> widget2 = Widget.objects.get(pk=2) + >>> Tag.objects.update_tags(widget2, 'cheese toast house') + >>> Tag.objects.usage_for_model(Widget) + [<Tag: cheese>, <Tag: house>, <Tag: thing>, <Tag: toast>] + +To get a count of how many times each tag was used for a particular +model, pass in ``True`` for the ``counts`` argument:: + + >>> tags = Tag.objects.usage_for_model(Widget, counts=True) + >>> [(tag.name, tag.count) for tag in tags] + [('cheese', 1), ('house', 2), ('thing', 1), ('toast', 1)] + +To get counts and limit the tags returned to those with counts above a +certain size, pass in a ``min_count`` argument:: + + >>> tags = Tag.objects.usage_for_model(Widget, min_count=2) + >>> [(tag.name, tag.count) for tag in tags] + [('house', 2)] + +You can also specify a dictionary of `field lookups`_ to be used to +restrict the tags and counts returned based on a subset of the +model's instances. For example, the following would retrieve all tags +used on Widgets created by a user named Alan which have a size +greater than 99:: + + >>> Tag.objects.usage_for_model(Widget, filters=dict(size__gt=99, user__username='Alan')) + +.. _`field lookups`: http://www.djangoproject.com/documentation/db-api/#field-lookups + +**New in development version** + +The ``usage_for_queryset`` method allows you to pass a pre-filtered +queryset to be used when determining tag usage:: + + >>> Tag.objects.usage_for_queryset(Widget.objects.filter(size__gt=99, user__username='Alan')) + +Tag input +--------- + +Tag input from users is treated as follows: + +* If the input doesn't contain any commas or double quotes, it is simply + treated as a space-delimited list of tag names. + +* If the input does contain either of these characters, we parse the + input like so: + + * Groups of characters which appear between double quotes take + precedence as multi-word tags (so double quoted tag names may + contain commas). An unclosed double quote will be ignored. + + * For the remaining input, if there are any unquoted commas in the + input, the remainder will be treated as comma-delimited. Otherwise, + it will be treated as space-delimited. + +Examples: + +====================== ======================================= ================================================ +Tag input string Resulting tags Notes +====================== ======================================= ================================================ +apple ball cat [``apple``], [``ball``], [``cat``] No commas, so space delimited +apple, ball cat [``apple``], [``ball cat``] Comma present, so comma delimited +"apple, ball" cat dog [``apple, ball``], [``cat``], [``dog``] All commas are quoted, so space delimited +"apple, ball", cat dog [``apple, ball``], [``cat dog``] Contains an unquoted comma, so comma delimited +apple "ball cat" dog [``apple``], [``ball cat``], [``dog``] No commas, so space delimited +"apple" "ball dog [``apple``], [``ball``], [``dog``] Unclosed double quote is ignored +====================== ======================================= ================================================ + + +Tagged items +============ + +The relationship between a ``Tag`` and an object is represented by +the ``TaggedItem`` model, which lives in the ``tagging.models`` +module. + +API reference +------------- + +Fields +~~~~~~ + +``TaggedItem`` objects have the following fields: + +* ``tag`` -- The ``Tag`` an object is associated with. +* ``content_type`` -- The ``ContentType`` of the associated model + instance. +* ``object_id`` -- The id of the associated object. +* ``object`` -- The associated object itself, accessible via the + Generic Relations API. + +Manager functions +~~~~~~~~~~~~~~~~~ + +The ``TaggedItem`` model has a custom manager which has the following +helper methods, which accept either a ``QuerySet`` or a ``Model`` +class as one of their arguments. To restrict the objects which are +returned, pass in a filtered ``QuerySet`` for this argument: + +* ``get_by_model(queryset_or_model, tag)`` -- creates a ``QuerySet`` + containing instances of the specififed model which are tagged with + the given tag or tags. + +* ``get_intersection_by_model(queryset_or_model, tags)`` -- creates a + ``QuerySet`` containing instances of the specified model which are + tagged with every tag in a list of tags. + + ``get_by_model`` will call this function behind the scenes when you + pass it a list, so you can use ``get_by_model`` instead of calling + this method directly. + +* ``get_union_by_model(queryset_or_model, tags)`` -- creates a + ``QuerySet`` containing instances of the specified model which are + tagged with any tag in a list of tags. + +.. _`get_related method`: + +* ``get_related(obj, queryset_or_model, num=None)`` - returns a list of + instances of the specified model which share tags with the model + instance ``obj``, ordered by the number of shared tags in descending + order. + + If ``num`` is given, a maximum of ``num`` instances will be returned. + +Basic usage +----------- + +Retrieving tagged objects +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Objects may be retrieved based on their tags using the ``get_by_model`` +manager method:: + + >>> from shop.apps.products.models import Widget + >>> from tagging.models import Tag + >>> house_tag = Tag.objects.get(name='house') + >>> TaggedItem.objects.get_by_model(Widget, house_tag) + [<Widget: pk=1>, <Widget: pk=2>] + +Passing a list of tags to ``get_by_model`` returns an intersection of +objects which have those tags, i.e. tag1 AND tag2 ... AND tagN:: + + >>> thing_tag = Tag.objects.get(name='thing') + >>> TaggedItem.objects.get_by_model(Widget, [house_tag, thing_tag]) + [<Widget: pk=1>] + +Functions which take tags are flexible when it comes to tag input:: + + >>> TaggedItem.objects.get_by_model(Widget, Tag.objects.filter(name__in=['house', 'thing'])) + [<Widget: pk=1>] + >>> TaggedItem.objects.get_by_model(Widget, 'house thing') + [<Widget: pk=1>] + >>> TaggedItem.objects.get_by_model(Widget, ['house', 'thing']) + [<Widget: pk=1>] + +Restricting objects returned +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Pass in a ``QuerySet`` to restrict the objects returned:: + + # Retrieve all Widgets which have a price less than 50, tagged with 'house' + TaggedItem.objects.get_by_model(Widget.objects.filter(price__lt=50), 'house') + + # Retrieve all Widgets which have a name starting with 'a', tagged with any + # of 'house', 'garden' or 'water'. + TaggedItem.objects.get_union_by_model(Widget.objects.filter(name__startswith='a'), + ['house', 'garden', 'water']) + + +Utilities +========= + +Tag-related utility functions are defined in the ``tagging.utils`` +module: + +``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. + +See `tag input`_ for more details. + +``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. + +``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``. + +``calculate_cloud(tags, steps=4, distribution=tagging.utils.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``. + + +Model Fields +============ + +The ``tagging.fields`` module contains fields which make it easy to +integrate tagging into your models and into the +``django.contrib.admin`` application. + +Field types +----------- + +``TagField`` +~~~~~~~~~~~~ + +A ``CharField`` that actually works as a relationship to tags "under +the hood". + +Using this example model:: + + class Link(models.Model): + ... + tags = TagField() + +Setting tags:: + + >>> l = Link.objects.get(...) + >>> l.tags = 'tag1 tag2 tag3' + +Getting tags for an instance:: + + >>> l.tags + 'tag1 tag2 tag3' + +Getting tags for a model - i.e. all tags used by all instances of the +model:: + + >>> Link.tags + 'tag1 tag2 tag3 tag4 tag5' + +This field will also validate that it has been given a valid list of +tag names, separated by a single comma, a single space or a comma +followed by a space, using the ``isTagList`` validator from +``tagging.validators``. + + +Form fields +=========== + +The ``tagging.forms`` module contains a ``Field`` for use with +Django's `newforms library`_ which takes care of validating tag name +input when used in your forms. + +.. _`newforms library`: http://www.djangoproject.com/documentation/newforms/ + +Field types +----------- + +``TagField`` +~~~~~~~~~~~~ + +A form ``Field`` which is displayed as a single-line text input, which +validates that the input it receives is a valid list of tag names. + +When you generate a form for one of your models automatically, using +the ``ModelForm`` class provided by newforms, any +``tagging.fields.TagField`` fields in your model will automatically be +represented by a ``tagging.forms.TagField`` in the generated form. + + +Generic views +============= + +The ``tagging.views`` module contains views to handle simple cases of +common display logic related to tagging. + +``tagging.views.tagged_object_list`` +------------------------------------ + +**Description:** + +A view that displays a list of objects for a given model which have a +given tag. This is a thin wrapper around the +``django.views.generic.list_detail.object_list`` view, which takes a +model and a tag as its arguments (in addition to the other optional +arguments supported by ``object_list``), building the appropriate +``QuerySet`` for you instead of expecting one to be passed in. + +**Required arguments:** + + * ``queryset_or_model``: A ``QuerySet`` or Django model class for the + object which will be listed. + + * ``tag``: The tag which objects of the given model must have in + order to be listed. + +**Optional arguments:** + +Please refer to the `object_list documentation`_ for additional optional +arguments which may be given. + + * ``related_tags``: If ``True``, a ``related_tags`` context variable + will also contain tags related to the given tag for the given + model. + + * ``related_tag_counts``: If ``True`` and ``related_tags`` is + ``True``, each related tag will have a ``count`` attribute + indicating the number of items which have it in addition to the + given tag. + +**Template context:** + +Please refer to the `object_list documentation`_ for additional +template context variables which may be provided. + + * ``tag``: The ``Tag`` instance for the given tag. + +.. _`object_list documentation`: http://www.djangoproject.com/documentation/generic_views/#django-views-generic-list-detail-object-list + +Example usage +~~~~~~~~~~~~~ + +The following sample URLconf demonstrates using this generic view to +list items of a particular model class which have a given tag:: + + from django.conf.urls.defaults import * + + from tagging.views import tagged_object_list + + from shop.apps.products.models import Widget + + urlpatterns = patterns('', + url(r'^widgets/tag/(?P<tag>[^/]+)/$', + tagged_object_list, + dict(model=Widget, paginate_by=10, allow_empty=True, + template_object_name='widget'), + name='widget_tag_detail'), + ) + +The following sample view demonstrates wrapping this generic view to +perform filtering of the objects which are listed:: + + from myapp.models import People + + from tagging.views import tagged_object_list + + def tagged_people(request, country_code, tag): + queryset = People.objects.filter(country__code=country_code) + return tagged_object_list(request, queryset, tag, paginate_by=25, + allow_empty=True, template_object_name='people') + + +Template tags +============= + +The ``tagging.templatetags.tagging_tags`` module defines a number of +template tags which may be used to work with tags. + +Tag reference +------------- + +tags_for_model +~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects associated with a given model and +stores them in a context variable. + +Usage:: + + {% tags_for_model [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +Extended usage:: + + {% tags_for_model [model] as [varname] with counts %} + +If specified - by providing extra ``with counts`` arguments - adds a +``count`` attribute to each tag containing the number of instances of +the given model which have been tagged with it. + +Examples:: + + {% tags_for_model products.Widget as widget_tags %} + {% tags_for_model products.Widget as widget_tags with counts %} + +tag_cloud_for_model +~~~~~~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects for a given model, with tag cloud +attributes set, and stores them in a context variable. + +Usage:: + + {% tag_cloud_for_model [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +Extended usage:: + + {% tag_cloud_for_model [model] as [varname] with [options] %} + +Extra options can be provided after an optional ``with`` argument, with +each option being specified in ``[name]=[value]`` format. Valid extra +options are: + + ``steps`` + Integer. Defines the range of font sizes. + + ``min_count`` + Integer. Defines the minimum number of times a tag must have + been used to appear in the cloud. + + ``distribution`` + One of ``linear`` or ``log``. Defines the font-size + distribution algorithm to use when generating the tag cloud. + +Examples:: + + {% tag_cloud_for_model products.Widget as widget_tags %} + {% tag_cloud_for_model products.Widget as widget_tags with steps=9 min_count=3 distribution=log %} + +tags_for_object +~~~~~~~~~~~~~~~ + +Retrieves a list of ``Tag`` objects associated with an object and stores +them in a context variable. + +Usage:: + + {% tags_for_object [object] as [varname] %} + +Example:: + + {% tags_for_object foo_object as tag_list %} + +tagged_objects +~~~~~~~~~~~~~~ + +Retrieves a list of instances of a given model which are tagged with a +given ``Tag`` and stores them in a context variable. + +Usage:: + + {% tagged_objects [tag] in [model] as [varname] %} + +The model is specified in ``[appname].[modelname]`` format. + +The tag must be an instance of a ``Tag``, not the name of a tag. + +Example:: + + {% tagged_objects comedy_tag in tv.Show as comedies %} |