Date picker

UI::DatePicker — a typed date field with a calendar beside it. Three inputs in one: what the user types (DD/MM/YYYY), what the form submits (ISO, hidden), and the calendar. The typed field comes first because people who know the date type it in a second: reaching a date years away in a calendar means clicking back month after month. The written format is not decided here. It comes from `date.formats.typed` in the locale, and this component derives the placeholder, the parse order and the separator from that one string — so a locale that writes dates differently changes what the field accepts, what it shows and what the hint says, together, with nothing hardcoded. The shipped English format is day-first; change `date.formats.typed` for month-first. A native date input follows the browser's locale instead, which is how the same form reads MM/DD on one machine and DD/MM on another, and how the 2nd of May gets recorded as the 5th of February. Cally is ~9 KB gzipped and loaded only when the calendar is first opened, so a form nobody opens a calendar on downloads nothing. Usage: <%= render(UI::DatePicker.new(form: f, field: :starts_on, required: true)) %> <%= render(UI::DatePicker.new(name: "event[date]", value: @date, label: "Date")) %>