CODEWITHSUNDEEP
pythondjangodjango-templates
thumbtackthief
thumbtackthief

Reputation: 6211

Use firstof and striptags

As part of a Facebook sharekit, I have this code:

data-share-description="{% firstof foo.bar foo.baz bang.pow bang.zap %}"

which returns the correct value, but includes HTML tags. If I add a "striptags" filter after each value, it seems that firstof is recognizing "None" as a non-False value and returning that instead rather than proceeding down the list.

EDIT:

foo.bar = ''
foo.baz = None
bang.pow = '<i>Italicized text</i> and some more'
bang.zap = 'Something else'

Without striptags after each firstof variable, it returns <i>Italicized text</i> and some more which is not what I want, but is what I expect. With strip tags, it prints out None. If I remove foo.baz from the firstof sequence, I get the expected and desired value of Italicized text and some more.

EDIT AGAIN:

Because foo.baz is None, striptags is throwing a TypeError of argument of type 'NoneType' is not iterable. I think this is the problem but no idea how to fix it.

Upvotes: 1

Views: 447

Answers (1)

Two-Bit Alchemist
Two-Bit Alchemist

Reputation: 18467

Since striptags seems to choke on None values, you could chain another call to default. That means you'd end up with something like this:

{% firstof foo.baz|default:''|striptags bar.quux|default:''|striptags %}

for each element in the list. I believe you'll agree this is quite cumbersome.

This is why I think it's time for you to create your own custom tag that performs this procedure for you:

from django import template
from django.utils.html import strip_tags

register = template.Library()

@register.simple_tag
def firstof_striptags(*args):
    for arg in args:
        if arg:
            return strip_tags(arg)

I'm not sure this fully complies with your use case and you may want to read up on some topics like Auto-escaping Considerations. This code is untested but should give you an idea what to do.

Upvotes: 2

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