Dart Package for formatting Latitude and Longitude values.

Features

• Flexible formatting through the use of templates.
• Includes support for Dates, Times and Time Zones.
• Supports additional information strings.

Usage

import 'package:latlong_formatter/latlong_formatter.dart';

void main() {
  LatLong ll = LatLong(5.346, -10.784);
  LatLongFormatter llf = LatLongFormatter(
      'Hi {info2},\n\nOn {utcyyyy-MM-dd} at {utcHH:mm} UTC, {info1} is at:\n\n{lat0d 0m.mmm c}, {lon0d 0m.mmm c}\n\nCheers\n{info}');
  print(llf.format(LatLong(5.346, -10.784), info: ['Joe Blogs', 'SV Billy Do', 'Fred']));
}

Would output:

Hi Fred,

On 2023-08-20 at 07:45 UTC, SV Billy Do is at:

05 20.760 N, 010 47.040 W

Cheers
Joe Blogs

and:

  LatLongFormatter llf = LatLongFormatter('{latd\u00B0m"s\' c},{lond\u00B0m"s\' c}');
  print(llf.format(ll));
  llf = LatLongFormatter('{lat-d\u00B0m"s\'},{lon-d\u00B0m"s\'}');
  print(llf.format(ll));
  llf = LatLongFormatter('{lat+d\u00B0m"s\'},{lon+d\u00B0m"s\'}');
  print(llf.format(ll));

Would output:

5°20"45' N,10°47"2' W
5°20"45',-10°47"2'
+5°20"45',-10°47"2'

Templates

Templates are free format with fields enclosed in '{}':

• {lat<loc format>} -- Latitude.
• {lon<loc format>} -- Longitude.
• {local<time format>} -- Local time.
• {utc<time format>} -- Time in UTC.
• {tz[hmn]+} -- Local Time Zone, e.g. 'h' gives "+06", 'm' gives "30" and 'n' gives "CCT".
• {info[index]?} -- Additional information line indexed from 0 (0 is optional).

Where <loc format> can be:

• [0]d -- degrees
• [0]d.d[dddd] -- decimal degrees
• [0]m -- minutes
• [0]m.m[mmmm] -- decimal minutes
• [0]s -- seconds
• [0]s.s[ssss] -- decimal seconds
• c -- cardinal direction, i.e. N,S,E or W.
• \- -- a "-" when South or West.
• \+ -- a "+" when North or East and "-" when South or West.

A leading "0" will pad the field to a fixed length.

Note: the decimal fields are internally rounded to 5 decimal places, so specifying more decimal places will not increase accuracy. This gives an accuracy of ~1m per-degree and ~2cm per-minute.

The <time format> can be anything defined for the DataFormat class.