Formsets in Django, it turns out, are hard. When I came to try and use them in anger outside the Django admin I found myself tripping over all sorts of problems. And as soon as I tried to use them in combination with the excellent Crispy Forms I found yet more problems.
Googling and StackOverflow both showed that lots (and I mean lots) of people were having very similar problems, but no one appears to have tackled it in a generic and repeatable way. In addition, rightly or wrongly, some projects have referred to the use of formsets as "an edgecase" and have deliberately exclude considering them. This simplifies the project, but often means that not only are they not considered, they're nigh on impossible to implement within that framework.
This project attempts to resolve some of those problems.
It is designed with the following philosophy in mind. If you disagree with any of the following statements then this may not be the project for you:
- Forms should completely understand themselves (how to lay themselves out, how to save their contents, everything)
- The
helperandlayoutapproach taken by Crispy Forms is a good one, or at the very least one worth extending to get the benefits that Crispy Forms bring- Django's Class Based Views are a Good Thing
To date all I'm doing is scratching my own itch, which is as follows:
- I am using the twitter bootstrap template pack, so no other template packs are supported yet (shouldn't be hard to fix though)
- I want inline formsets at any point within a form, rendered as a table
- I am only working with ModelForms at the moment (the source for this comes from a CRUD heavy application)
What it does solve:
- Formsets for GenericRelations
- Formsets for ManyToMany relations with intermediate tables
- Using formsets within CBVs without lots of faffing (properly DRY, you might say)
The initial work is based on this pull request on the original django-uni-forms:
Initially I was a bit pissed that Miguel had rejected the pull until I realised that it was essentially incomplete. There was a whole set of work to be done both in laying out the forms and in saving the results which I've tackled here. I've chosen to implement it as an extension to Crispy Forms rather than on the main package because the code here simply isn't up to the standard required of a package as widely used as Crispy Forms yet, and may never be.
I hope, however, that it helps other people who've been struggling with similar problems.
More documentation to come.