custom django templatetags libraries

[eudicots]

custom django templatetags libraries

[rukeba]

+1

[stepmr]

+1

[moskrc]

+1

[WillsB3]

Can anyone tell me what the status is here? I'd like to know if (and how) to create and use custom Django template tags with Cactus?

Thanks.

[krallin]

You can actually do this today (at least in v3, which is now the master version) using a plugin.

Here's an example:

from django import template
from django.template.loader import get_template

def signup_button(context, location):
    """
    Display the signup button
    """
    ctx = copy.copy(context)
    ctx.update({"loc": location})
    return ctx

def preBuild(_):
    register = template.Library()
    register.inclusion_tag(get_template('includes/buttons/signup-button.html'), takes_context=True)(signup_button)
    template.base.builtins.append(register)

Note that it's probably possible to clean this up a bit (and not hack into builtins). Looking at how Django loads new templatetags files is probably the best way to find out.

I seem to recall I had injected into builtins to not have to re-load this tag which was going to be used on every single page of my website, but I'm sure there's a cleaner way.

[WillsB3]

Thanks @krallin - I'll give that a go 👍

[krallin]

Let me know if you run into any trouble. It's been a while since I used that plugin, but I'm pretty sure that site used to build so there has to be a way to make it work! : )

[pmdarrow]

@krallin the snippet you posted doesn't seem to work. I tried it with a really simple filter:

from django import template

def mymarkdown(value):
    return 'test'

def preBuild(site):
    register = template.Library()
    register.filter('mymarkdown', mymarkdown)

Which gives me:

django.template.base.TemplateSyntaxError: Invalid filter: 'mymarkdown'

[pmdarrow]

Update: the following works

from cactus.template_tags import register

def mymarkdown(value):
    return 'test'

def preBuild(site):
    register.filter('mymarkdown', mymarkdown)

[krallin]

@pmdarrow ,

You might have missed that line from the snippet:

template.base.builtins.append(register)

If you don't add that line, then you'd have to {% load ... %} the library.

Cheers,

[pmdarrow]

@krallin I'm writing a custom filter, and I registered it with Cactus' library using

from cactus.template_tags import register
register.filter('mymarkdown', mymarkdown)

so no builtins hacking was required.

[krallin]

@pmdarrow ,

I understand that. I was simply explaining why the snippet I provided did not work for you.

Basically, there are two ways to add a filter:

• Add the filter to a new library, and add that library to the built-ins (what I had originally suggested).
• Add the filter to a library that is already present in the built-ins (this is what you did).

Note that the cactus.template_tags library is added to the Django built-ins for you by Cactus:

https://github.com/koenbok/Cactus/blob/2dd7159280363f0b762d43e3bfa1ec1a2a6effea/cactus/site.py#L156

So, there's still builtins hacking, only it's not your plugin doing it ;)

Now, obviously, both ways work equally well! : )

Cheers,

[pmdarrow]

@krallin ah, that makes sense 😃. It would be awesome if there was some docs for this, but I see that's on the roadmap in #117. Might be worth closing this issue now that there's a solution.