latlon-formatter


A set of functions to format latitude and longitude angles.

Installation

``bash
npm install latlon-formatter --save
`



Usage

- ES6:

`javascript
import { formatLatitude, formatLongitude } from 'latlon-formatter';
const latitude = formatLatitude(Math.PI / 3); // => 60° 00′ 00″ N
const longitude = formatLongitude(-33.4, {
degrees: true
}); // => 034° 24′ 00″ W
`

- require with Node.js:

`javascript
var formatter = require('latlon-formatter');
var latitude = formatter.latitude(Math.PI / 3); // => 60° 00′ 00″ N
var longitude = formatter.longitude(-33.4, {
degrees: true
}); // => 034° 24′ 00″ W
`

- in browser include dist/latlon-formatter.js or dist/latlon-formatter.min.js script:

`javascript
var formatter = window.latlonFormatter;
var latitude = formatter.latitude(Math.PI / 3); // => 60° 00′ 00″ N
var longitude = formatter.longitude(-33.4, {
degrees: true
}); // => 034° 24′ 00″ W
`



Methods

- latitude or formatLatitude — format latitude angle.

Arguments:

- value — angle's value;
- options:
- template — custom template (optional, default — {degree}° {prime}′ {doublePrime}″ {direction});
- degrees — specifies whether value is in degrees or in radians (optional, default — false);
- fixedCount — count of precision digits (optional, default — null leaving precision as is).

Examples:

`javascript
formatter.latitude(33.4); // => 34° 24′ 00″ N
`

`javascript
formatter.latitude(-14.75, { degrees: true }); // => 14° 45′ 00″ S
`

`javascript
formatter.latitude(-14.75, {
template: '{negativeSign}{value}°',
degrees: true,
fixedCount: 1
}); // => —14.8°
`

- longitude or formatLongitude — format longitude angle.

Arguments:

- value — angle's value;
- options:
- template — custom template (optional, default — {degree}° {prime}′ {doublePrime}″ {direction});
- degrees — specifies whether value is in degrees or in radians (optional, default — false);
- fixedCount — count of precision digits (optional, default — null leaving precision as is).

Examples:

`javascript
formatter.longitude(33.4); // => 034° 24′ 00″ E
`

`javascript
formatter.longitude(-14.75, { degrees: true }); // => 014° 45′ 00″ W
`

`javascript
formatter.longitude(-14.75, {
template: '{negativeSign}{value}°',
degrees: true,
fixedCount: 1
}); // => —14.8°
`

- angle or formatAngle — format any custom angle.

Arguments:

- value — angle's value;
- options:
- template — custom template (optional, default — {negativeSign}{value}°);
- degrees — specifies whether value is in degrees or in radians (optional, default — false);
- fixedCount — count of precision digits (optional, default — null leaving precision as is);
- customTokens — an object or a function returning an object of additional custom tokens used in template.

Examples:

`javascript
formatter.angle(3.4, {
template: '{degree}° {prime}′ {doublePrime}″ {direction}',
customTokens: f => {
return {
degree: (f.degrees < 10 ? '0' : '') + f.degree,
direction: f.sign >= 0 ? 'N' : 'S'
};
}
}); // => 03° 24′ 00″ N
`



Template tokens



All three format methods (latitude, longitude and angle) have the following predefined template tokens:

- value — angle's absolute value with optional precision specified by fixedCount option;
- degree — absolute (two-digits and three-digits for latitude and longitude respectively) degree value;
- prime — absolute two-digits prime value;
- doublePrime — absolute two-digits double prime value;
- sign — value's sign:
- + — positive value;
- — — negative value;
- empty — zero value;
- negativeSign — the same as sign except that it's empty for both zero and positive values.

latitude and longitude methods additionally have direction token:
- N — non-negative latitude;
- S — negative latitude;
- E — non-negative longitude;
- W — negative longitude.

Any custom additional tokens can be specified by customTokens option of angle method.



Building

In order to build library run:

npm run build



Testing

Run unit tests:

npm test

Run tests with coverage:

npm run test:coverage

In order to run tests with Coveralls locally you have to provide COVERALLS_REPO_TOKEN:

COVERALLS_REPO_TOKEN= npm run test:coveralls



Contributing



Before making a pull request, please, be sure that you start from develop` branch.

License

MIT