formatter: add function to convert list to appropriate format (
issue5217)
Before, it wasn't possible for formatter to handle array structure other
than date tuple. We've discussed that at the last sprint, which ended we
would probably want to allow only templatable data structure, i.e. a list
of dicts:
data(tags=[{'tag': a}, {'tag': b}, ...])
Unfortunately, it turned out not working well with template functions:
"{ifcontains(a, tags, ...)}"
^^^^^^^^^^^^^^^^^^
"a in tags", where tags should be a plain list/set of tags
So the formatter must at least know if the type [{}] was constructed from
a plain list or was actually a list of dicts.
This patch introduces new explicit interface to convert an array structure
to an appropriate data type for the current formatter, which can be used
as follows:
fm.write('tags', _('tags: %s\n'), fm.formatlist(tags, name='tag'))
No separate fm.data() call should be necessary.