What is it ?

A simple Django TemplateTag (named compute_tag_cloud) to help in the creation of tag clouds.

Tiny tutorial

Install the app in your Django project

This should be as simple as

pip install django-nuages-tag

and adding ‘django_nuages_tag’ to your INSTALLED_APPS settings.

Example usage

1. Source data

Given that we have a my_favourite_tools context variable defined like this:

my_favourite_tools = [{'name': 'Python', 'interest': 30},
                      {'name': 'Django', 'interest': 70},
                      {'name': 'Ruby', 'interest': 6}]

Note: example shows a simple list, but this also works with a Django QuerySet.

We can now do:

{% load django_nuages_tag %}

{% compute_tag_cloud my_favourite_tools interest font_size 10 100 lin %}

compute_tag_cloud will add a font_size attribute to each element in my_favourite_tools that is contained between 10 and 100 and is representative of the value of interest. The last parameter (lin) asks to use a linear formula to compute this tag cloud. Another option is to use a logarithmic formula (use the log parameter). You should test both options, but log will probably give you better results if there is a large variation in the values you want to compute. NOTE: 0 and negative values will be computed to 0 (with both formulas).

Our source data now looks like:

my_favourite_tools = [{'name': 'Python', 'interest': 30, 'font_size': 43.75},
                      {'name': 'Django', 'interest': 70, 'font_size': 100},
                      {'name': 'Ruby', 'interest': 6, 'font_size': 10}]

This can be done very easily with the for tag and basic HTML/CSS. For example:

{% for tool in my_favourite_tools %}
  <span style="font-size: {{ tool.font_size }}px;"> {{ tool.name }} </span>
{% endfor %}

Notes

compute_tag_cloud can be called multiple times in a row to generate multiple values. We can for example compute the font size (between 10 and 55), but also the margin (between 5 and 28) and the opacity (between 0.7 and 1) of the text with something like:

{% load django_nuages_tag %}

{% compute_tag_cloud my_favourite_tools interest font_size 10 55 lin %}
{% compute_tag_cloud my_favourite_tools interest margin 5 28 lin %}
{% compute_tag_cloud my_favourite_tools interest opacity 0.7 1 lin %}

{% for tool in my_favourite_tools %}
  <span style="font-size: {{ tool.font_size }}px; margin: {{ tool.margin }}px; opacity: {{ tool.opacity }}">{{ tool.name }}</span>
{% endfor %}

The counter parameter (interest in our example) can be an attribute, a method to be called or a dictionary key.

niconoe/django-nuages-tag