Assets of components not output if `render_to_string` is used

[joshuadavidthomas]

I've got a django-tables2 table, where in one of the columns I'm rendering to string another partial template that has a component defined in it. It's a modal, so I've got a modal.js alongside it for defining the behavior. Based on the scanning logic currently, there's no way for the parent table template to know it's using a certain component.

In [5]: components._template_usage
Out[5]:
defaultdict(set,
            {PosixPath('/app/templates/base.html'): {'indicator'},
             PosixPath('/app/templates/invoices/partials/adjust_acres.html'): {'description.details',
              'description.list',
              'description.term',
              'modal',
              'modal.trigger'},
             PosixPath('/app/templates/invoices/partials/adjust_rate.html'): {'description.details',
              'description.list',
              'description.term',
              'modal',
              'modal.trigger'}})

So either the adjust_acres.html or adjust_rate.html have the component defined and if I was just rendering that partial, the {% bird:js %} tag would render the correct modal.js tag. But since I'm rendering it ahead of time before rendering the actual page or table within that page, it doesn't output anything.

Currently getting around this by including the component in a comment in the main template, so it doesn't actually get render but does get picked up by the template scanning:

  {# comment #}
  {% bird modal %}
  {% endbird %}
  {# endcomment #}

[joshuadavidthomas]

One workaround would be to parse rendered templates for the data-bird-* attributes for the component name and use that in addition to the current way templates are scanned.

It would be at runtime during the asset tag rendering, so we would need to make sure it's quick. Also It wouldn't help if someone isn't using the bird data attributes, but that could be an okay trade off. At least as a stopgap until a more complete solution reveals itself.

[joshuadavidthomas]

Alternatively, a tag to put on templates that would mark it as always loading a certain component might be nice?

# partial.html
{% bird button %}
    Partially click me!
{% endbird %}

# template.html
{% bird:load button %}

{{ partial_content }}

That way template.html could be marked as requiring the button component and you could do something like:

from django.shortcuts import render
from django.template.loader import render_to_string

def partial_render_to_context(request):
    partial_content = render_to_string("partial.html")
    return render("template.html", {"partial_content": partial_content})

[joshuadavidthomas]

That way, you could even mark certain components as basically 'required' components to always load their assets by putting the {% bird:load %} tag on a base template, either for the entire site or a subsection.

[joshuadavidthomas]

This is definitely related to #66