Add DateTime to_rfc3339p(z) methods, tests

These additions allow convenient control of RFC 3339 formatted output:

 * Number of subsecond digits to display

 * Whether to use the 'Z' variant, instead of "+00:00" for TZ offset
   0, UTC.

...while remaining faithful to the RFC 3339. The implementation uses
the existing formatting Item mechanism.

github: cc: #157 #178
This commit is contained in:
David Kellum 2018-01-11 15:50:57 -08:00
parent 232a0f1255
commit d2bf1494b1
1 changed files with 95 additions and 0 deletions

View File

@ -246,6 +246,23 @@ impl<Tz: TimeZone> DateTime<Tz> where Tz::Offset: fmt::Display {
self.format_with_items(ITEMS.iter().cloned()).to_string()
}
/// Return an RFC 3339 and ISO 8601 date and time with subseconds formatted
/// as per a Fixed variant or None for no subseconds. The Fixed
/// variants supported are: Nanosecond, Nanosecond3, Nanosecond6
/// and Nanosecond9. Other values will panic!
pub fn to_rfc3339p(&self, subform: Option<Fixed>) -> String {
self.rfc3339_via_items(subform, false)
}
/// Return an RFC 3339 and ISO 8601 date and time with subseconds formatted
/// as per a Fixed variant or None for no subseconds. The Fixed
/// variants supported are: Nanosecond, Nanosecond3, Nanosecond6
/// and Nanosecond9. Other values will panic!
/// If the timezone is UTC (offset 0), use 'Z'.
pub fn to_rfc3339pz(&self, subform: Option<Fixed>) -> String {
self.rfc3339_via_items(subform, true)
}
/// Formats the combined date and time with the specified formatting items.
#[inline]
pub fn format_with_items<'a, I>(&self, items: I) -> DelayedFormat<I>
@ -261,6 +278,54 @@ impl<Tz: TimeZone> DateTime<Tz> where Tz::Offset: fmt::Display {
pub fn format<'a>(&self, fmt: &'a str) -> DelayedFormat<StrftimeItems<'a>> {
self.format_with_items(StrftimeItems::new(fmt))
}
fn rfc3339_via_items(&self, subform: Option<Fixed>, use_z: bool) -> String
{
use format::Item::*;
use format::Numeric::*;
use format::Pad::Zero;
use format::Fixed::*;
use format::Fixed::Nanosecond;
static PREFIX: &[Item<'static>] = &[
Numeric(Year, Zero),
Literal("-"),
Numeric(Month, Zero),
Literal("-"),
Numeric(Day, Zero),
Literal("T"),
Numeric(Hour, Zero),
Literal(":"),
Numeric(Minute, Zero),
Literal(":"),
Numeric(Second, Zero),
];
let ssitem = match subform {
None => None,
Some(sf) => match sf {
Nanosecond |
Nanosecond3 | Nanosecond6 | Nanosecond9 => Some(Fixed(sf)),
_ => panic!("Unsupported rfc_3339p subsecond format {:?}", sf)
}
};
let tzitem = Fixed(match use_z {
true => TimezoneOffsetColonZ,
false => TimezoneOffsetColon
});
match ssitem {
None =>
self.format_with_items(
PREFIX.iter().chain([tzitem].iter()).cloned()
).to_string(),
Some(s) =>
self.format_with_items(
PREFIX.iter().chain([s, tzitem].iter()).cloned()
).to_string(),
}
}
}
impl<Tz: TimeZone> Datelike for DateTime<Tz> {
@ -1059,6 +1124,36 @@ mod tests {
Ok(EDT.ymd(2015, 2, 18).and_hms_micro(23, 59, 59, 1_234_567)));
}
#[test]
fn test_rfc3339p_and_z() {
use format::Fixed::*;
let pst = FixedOffset::east(8*60*60);
let dt = pst.ymd(2018, 1, 11).and_hms_nano(10, 5, 13, 84_660_684);
assert_eq!("2018-01-11T10:05:13+08:00", dt.to_rfc3339p (None));
assert_eq!("2018-01-11T10:05:13+08:00", dt.to_rfc3339pz(None));
assert_eq!("2018-01-11T10:05:13.084+08:00", dt.to_rfc3339p (Some(Nanosecond3)));
assert_eq!("2018-01-11T10:05:13.084660+08:00", dt.to_rfc3339p (Some(Nanosecond6)));
assert_eq!("2018-01-11T10:05:13.084660684+08:00", dt.to_rfc3339p (Some(Nanosecond9)));
assert_eq!("2018-01-11T10:05:13.084660684+08:00", dt.to_rfc3339p (Some(Nanosecond)));
let ut = DateTime::<Utc>::from_utc( dt.naive_utc(), Utc );
assert_eq!("2018-01-11T02:05:13+00:00", ut.to_rfc3339p (None));
assert_eq!("2018-01-11T02:05:13Z", ut.to_rfc3339pz(None));
assert_eq!("2018-01-11T02:05:13.084+00:00", ut.to_rfc3339p (Some(Nanosecond3)));
assert_eq!("2018-01-11T02:05:13.084Z", ut.to_rfc3339pz(Some(Nanosecond3)));
assert_eq!("2018-01-11T02:05:13.084660Z", ut.to_rfc3339pz(Some(Nanosecond6)));
assert_eq!("2018-01-11T02:05:13.084660684Z", ut.to_rfc3339pz(Some(Nanosecond9)));
assert_eq!("2018-01-11T02:05:13.084660684Z", ut.to_rfc3339pz(Some(Nanosecond)));
}
#[test]
#[should_panic]
fn test_rfc3339p_fixed_bogus_n() {
use format::Fixed::*;
let now = Utc::now();
println!("{}", now.to_rfc3339p(Some(UpperAmPm)));
}
#[test]
fn test_datetime_from_str() {
assert_eq!("2015-2-18T23:16:9.15Z".parse::<DateTime<FixedOffset>>(),