Django snippets: Verbose template filter : avoid too many if

Verbose template filter : avoid too many if

from django import template                  

register = template.Library()

@register.filter
def verbose(value, arg):
    try:    
        if not value:
            return ''
        return arg % value
    except Exception:
        return str(value)

This tiny template filter saves you the tedious test "if this variable is set, print this text based on this variable".

'verbose' filter takes one parameter : a string containing '%s' which is a placeholder for the value to test. Check those examples :

Replace this :

{% if name %} Hello {{ name }}, this is a dummy text {% endif %}
By this :

{{ name|verbose:"Hello %s this is a dummy text" }}

This is also usefull for HTML :

{{ image|verbose:"<img src=\"%s\" />" }}

Author:: Romain Hardouin
Posted:: June 11, 2008
Language:: Python
Tags:: filter template
Score:: 9 (after 9 ratings)

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Comments

marvoloe (on June 12, 2008):

Great idea.

rachid (on June 12, 2008):

perfect!

carljm (on June 16, 2008):

Good stuff, very handy. If used for HTML as in the last example, don't forget to tag on the |safe filter, too.