In 674c27a693 we updated the autofocus
Javascript to be compatible with GOV.UK Frontend textboxes, which have
the `data-module` attribute set on the `input` element, rather than on
a wrapper element.
However we still have some `<textarea>`s and `<input>`s which haven’t
moved to GOV.UK Frontend and therefore aren’t getting picked up by the
Javascript which is supposed to focus them.
This commit makes the Javascript work with both kinds of textbox, which
is needed until we move entirely to GOV.UK Frontend.
Doing this was helpful to Voiceover users as its
announcement of the label meant the page title
(normally announced onload) wasn't skipped.
This isn't the case with JAWS so, prefixing the
title makes it announce it twice.
JAWS has a lot more users and the title being
announced twice is more confusing than not at all
so this removes it.
Screenreaders announce the title of the page when
it loads and their users are used to it signifying
a new page.
By focusing a form control when the page loads,
this announcement is replaced with that of the
control label.
This commit prefixes the label with the page title so it
gets announced when the page loads, notifying
screenreader users that they are on a new page.
The page title prefix is removed once focus shifts
from the form control as its presence in any
further announcements could be confusing.
Since moving textboxes to GOV.UK Frontend we’ve started putting the
data attribute on the `input` element itself, not a wrapper around it.
This commit updates the Javascript accordingly.
If users scroll a page with an autofocus component
on so it is off-screen it seems safe to assume
they won't want it focused if they return to it.
This prevents that happening.
This adds a data-attribute flag to allow this
behaviour to be overridden.
We have some situations where the assumption here
isn't appropriate, for example on pages where the
component with autofocus is in a sticky element.
This means it will appear offscreen when the page
loads but, when its parent becomes sticky, will be
visible again.
This commit adds a very small Javascript module to autofocus a textbox on page
load. It should only be used once per page.
It also adds a parameter to the textbox macro which adds the attribute to
trigger autofocus.
