Expand format_html_join() to allow keyword formatting

[Adam Johnson]

​`format_html_join()` currently allows formatting positional arguments only. It would be nice if it expanded support to allow keyword arguments, like the underlying format_html() does. Keyword arguments would come from an iterable of mappings (dicts and dict-like objects). This would allow less repetition when a value is used multiple times in the template string, like:

from django.utils.html import format_html_join

html = format_html_join(
    "\n",
    '<li data-id="{id}">{title} ({id})</li>',
    [
        {"id": book.id, "title": book.title}
        for book in books
    ]
)

and even:

from django.utils.html import format_html_join

html = format_html_join(
    "\n",
    '<li data-id="{id}">{title} ({id})</li>',
    Book.objects.values("id", "title")
)

[Claude Paroz]

Makes totally sense to me!

[Mohamed Nabil Rady]

How should the function behave if we want to use only args, only kwargs, or both ?

from django.utils.html import format_html_join

html = format_html_join(
    "\n",
    '<li data-id="{id}">{title} ({id})</li>',
    [
        {"id": book.id, "title": book.title}
        for book in books
    ]
)

How will this example work ? The third argument should the args generator.

[Adam Johnson]

The idea is that if the third argument contains mappings (dicts or dict-like objects), the formatting uses them as kwaegs, rather than as args. Arg and kwarg modes will be exclusive.

[Mohamed Nabil Rady]

​PR

[Sarah Boyce <42296566+sarahboyce@…>]

In 231c0d85:

Fixed #35668 -- Added mapping support to format_html_join.