jsexpr

JSON Expressions!


String and JSON expression interpolator and evaluator. Interpolates or evaluates a string against a json object, or transforms an object into another based on a json template.

Installation

``
npm install jsexpr
`

String Evaluation

`javascript
const expression = require("jsexpr");

var fn = expression.fn("(${host}=='mymachine' || ${host}=='yourmachine') && ${appName}=='su'");

// Result: false
var result = fn({host:"mymachine",appName:23});
`

String Interpolation

`javascript
const expression = require("jsexpr");

var expr = expression.expr("/var/${date}/${client.address}/file.log");

// Result: /var/2017-01-01/localhost/file.log
var result = expr({date:"2017-01-01",client:{address:"localhost"}});
`

Object Interpolation

`javascript
const expression = require("jsexpr");

var jsexpr = expression.expr({
time : "${client}/${address.host}:${address.port}",
data : {
request : {
headers : "${headers}"
}
}
});

var result = jsexpr({
client : "HOST001",
address : {
host : "localhost",
port : 8080
},
headers : "Content-Type: application/json"
});
`

$3

`javascript
{
time: 'HOST001/localhost:8080',
data: {
request: {
headers: 'Content-Type: application/json'
}
}
}
`

$3

`javascript
var input1 = {client : "HOST001", address : {host : "localhost", port : 8080}, headers : "Content-Type: application/json"};

let jxpr1 = expr.expr("${JSON}");
let jxpr2 = expr.expr("${JSON:address}");
let jxpr3 = expr.expr("${JSON:address:0}");
let jxpr4 = expr.expr("${JSON:0}");

// =>

{
"client": "HOST001",
"address": {
"host": "localhost",
"port": 8080
},
"headers": "Content-Type: application/json"
}

{
"host": "localhost",
"port": 8080
}

{"host":"localhost","port":8080}

{"client":"HOST001","address":{"host":"localhost","port":8080},"headers":"Content-Type: application/json"}
``