Defining "global variable" in Django templates

Question

I'm doing something like:

{% extends 'base.html' %}
{% url myapp.views.dashboard object as object_url %}
{% block sidebar %}
... {{ object_url }} ...
{% endblock %}
{% block content %}
... {{ object_url }} ...
{% endblock %}

Django documentation says url templatetag can define a variable in context, but I don't get any value for object_url in the following blocks.

If I put the url templatetag at the beginning of each block, it works, but I don't want to "repeat myself".

Anyone knows a better solution?

Answer 1

If the URL is view specific, you could pass the URL from your view. If the URL needs to be truly global in your templates, you could put it in a context processor:

def object_url(request):
    return {'object_url': reverse('myapp.views.dashboard')}

Answer 2

You could write a custom template tag:

@register.simple_tag(takes_context=True)
def set_global_context(context, key, value):
    """
    Sets a value to the global template context, so it can
    be accessible across blocks.

    Note that the block where the global context variable is set must appear
    before the other blocks using the variable IN THE BASE TEMPLATE.  The order
    of the blocks in the extending template is not important. 

    Usage::
        {% extends 'base.html' %}

        {% block first %}
            {% set_global_context 'foo' 'bar' %}
        {% endblock %}

        {% block second %}
            {{ foo }}
        {% endblock %}
    """
    context.dicts[0][key] = value
    return ''