The Design System has standardised on back links being at the top of the
page, decorated with a small text-coloured arrow.
I think this makes more sense than having them at the bottom, because it
suggests, in some way, being able to go back before commiting to any of
the forms on the page. Whereas the things at the bottom of the page
should be performing actions on what’s in the page.
The reason for making this change now is that it de-clutters the area
around the green buttons. This was presenting a design challenge where
multiple levels of interaction were happening in the same form. Moving
these back links to the top of the page should mean that, in these
complicated forms, there’s one fewer thing to compete for the user’s
attention.
I’ve componentised this into a `page_header` macro so that the change is
easier to roll out and maintain.
This will stop us repeatedly forgetting to add `novalidate` and
`autocomplete='off'` to our forms (which is how most of them are set
up).
It uses sensible defaults, based on how we most-commonly configure
forms:
- most of our forms are `post`ed (but this can be overridden)
- `autocomplete` should only be enabled where it makes sense, otherwise
it’s more annoying than useful (but this can be overriden)
- we should never be using HTML5 form validation because our own error
styles and messages are better
