In my earlier post, I walked you through the process I took to adapt this blog, with its existing data, to include tagging under the hood. In this post, I will cover the process of making the tags useful to your visitors.

The first thing to do is make a view to filter your model, or queryset, by tag. You have it easy because django-tagging includes a view built on top of django.views.generic.list_detail.object_list. You can add a tag filtered list as easily as adding a line like this to the urlpatterns in your urls.py:

(r'^tag/(?P<tag>[^/]+)/$', 'tagging.views.tagged_object_list',
    dict(queryset_or_model=MyModel)),

Going to http://yourdjangosite/tag/python/ would now bring up a list of MyModel instances featuring a python tag, assuming you have a myapp/mymodel_list.html template written up. How will your users navigate to this view? On this blog, I first have a collection of links under each post. These are simple to make. The code is something like this in the template:

{% load tagging_tags %}
<div>
    Tagged as:
    {% for tag in object.tags %}
        <a href="/tag/{{ tag }}/">{{ tag }}</a>
    {% endfor %}
</div>

On this blog, I also have a nice list of tags on the right with the count of posts bearing each tag. Here is the code for this:

{% load tagging_tags %}
<div class="header">Tags</div>
<div class="indent">
{% tags_for_model blog.Entry as entry_tags with counts %}
{% for entry_tag in entry_tags %}
    <div>
        <a href="/tag/{{ entry_tag }}/">{{ entry_tag }}</a>
        <span class="tag_count">({{ entry_tag.count }})</span></div>
{% endfor %}
</div>

That is just too easy, but maybe you want a tag cloud, like the one on my other site. Here is the code for the tag cloud from that very site:

{% load tagging_tags %}
<div class="tagbox">
    <div class="header">Filter by Tag:</div>
    <div class="group">
        {% tag_cloud_for_model deltad.Entry as entry_tags with steps=10 min_count=1 distribution=log %}
        {% for tag in entry_tags %}
            <a class="tag{{ tag.font_size }}" href="/tag/{{ tag }}/">{{ tag }}</a>
        {% endfor %}
    </div>
</div>

The tag_cloud_for_model tag gives me a entry_tags object with 10 levels of size distributed in logarithmic order as long as there is at least one entry bearing the tag. If you look carefully, you will notice that I am using the tag.font_size to classify my anchors. You can do whatever you want with this number. I just like to keep all appearance information in CSS.