interpolate-json 

!GitHub Workflow Status (with event)  

Interpolate a Javascript Object (json) or string with (another) json - Advanced (or Substitution, as others may like to call it).

Minimalist & lightweight ;) approach to handle interpolation, which packs way more punch than simple string parameter replacement.

Supports:

1. ${string} interpolation
2. ${json} interpolation
3. ${multi.level} json notation
4. single ${= JavaScript.expression() =} evaluation
5. custom {{parameter_boundary}} declaration

Install

``bash


with npm

npm install interpolate-json

or with Yarn

yarn add interpolate-json
`

Usage

#### Declaration

`javascript
// declare the varible at the beginning
const interpolation = require('interpolate-json').interpolation;
// or
const { interpolation } = require('interpolate-json');
`
`typescript
// or the import syntax
import { interpolation } from 'interpolate-json';
`

#### string

`javascript
// String
let someString = 'I want to be ${character} in ${business.type} by being a ${business.post}';
let values = {
character: 'a Hero',
business: {
type: 'saving people',
post: 'Doctor',
},
};
someString = interpolation.expand(someString, values);
console.log(someString);
// output: I want to be a Hero in saving people by being a Doctor

// or using ENVIRONMENT_VARIABLES
// test-string.js
let someString = "Hi, my name is '${USER_NAME}'. I'm ${USER_AGE}";
console.log(interpolation.expand(someString, process.env));
// execute using: USER_NAME='John' USER_AGE=19 node test-string.js
// output: Hi, my name is 'John'. I'm 19
`

#### json

`javascript
// Json
let myJson = {
port: '8080',
server: 'www.example.com',
user: 'abcd',
password: 'P@ss#ord',
url: 'https://${user}:${= encodeURIComponent(${password}) =}@${server}:${port}'
};
console.log(interpolation.expand(myJson)); // Look for values inside itself
// output:
{
"port": "8080",
"server": "www.example.com",
"user": "abcd",
"password": "P@ss#ord",
"url": "https://abcd:P%40ss%23ord@www.example.com:8080"
}

// Let's sweeten the deal with ENVIRONMENT_VARIABLES
// test-json.js
let myJson = {
port: '${PORT}',
server: 'www.example.com',
user: '${=${USER_NAME}.toLowerCase()=}',
password: '${USER_PASSWORD}',
url: 'https://${user}:${= encodeURIComponent(${password}) =}@${server}:${port}'
};

console.log(interpolation.expand(myJson));
// execute using: PORT=8080 USER_NAME='John' USER_PASSWORD='P@ss#ord' node test-json.js
// output:
{
"port": "8080",
"server": "www.example.com",
"user": "john",
"password": "P@ss#ord",
"url": "https://john:P%40ss%23ord@www.example.com:8080"
}

`

> Notice that ${= =}` notation. It's a cool way to use JavaScript expression (not expression_s_, yet, just a single line).

Get the full documentation in WIKI