string-interp

A small library to do shell-style string interpolation, with extensions to make it useful to prepare messages shown to the user.

This is the library used to replace placeholders in Thingpedia formatted strings.

Usage

const interp = require('string-interp');

// returns "foo bar baz"
interp('foo $p1 ${p2}', { p1: 'bar', p2: 'baz' }, { locale: 'en-US' });

Syntax

The syntax recognizes parameters preceded by a dollar sign $.

In the short form, the parameter name follows the dollar sign immediately. In this case, all identifier-like letters following the dollar sign are considered part of the parameter name. Example:

interp('$a $a$aa$a,a', { a: '1', aa: '2' }) === '1 121,a'

In the long form, the parameter name is wrapped in {}. Use this form if the parameter is immediately followed by another letter or number. Example:

interp('${a} ${a}a ${aa}', { a: '1', aa: '2' }) === '1 1a 2'

In the long form the parameter can be followed by an option, separated with :. Options affect how the parameter value is transformed into a string. Example:

interp('${a} ${a:url}', { a: '/' }) === '/ %2F'

Available options

General options:

• url: URL-encode the value with encodeURIComponent

Options for Date:

• iso-date: format a Date object as an ISO 8661 string.