jsonpath-filter

Filter javascript objects using an allow list of jsonpath expressions.

Includes a utility jsonfilter which can filter json files.

The javascript filter function, jsonfilter

import { jsonfilter } from 'jsonpath-filter';

const data = {
    foo: 'bar'
};
const result = jsonfilter(data, '$.foo');
// { foo: 'bar' }

The update filter function, update

import { update } from 'jsonpath-filter';

const data = {
    foo: 'bar',
    wee: 'woo',
};
const result = update(data, 'baz', '$.foo');
// { foo: 'baz', wee: 'woo' }

Be careful about arrays

If your jsonpath expression matches only some array entries, then you will retrieve them
with the correct index. Entries prior to that in the array will be `undefined`.

const data = {
    foo: ['a', 'b', 'c']
};
const result = jsonfilter(data, '$.foo[2]');
// { foo: [undefined, undefined, 'c'] }

Using the jsonfilter tool

cat > sample.json < HERE
{
  "foo": "bar",
  "baz": "quux",
  "zip": [
    { "name": "alice", "age": 22 },
    { "name": "bob", "age": 16 },
    { "name": "charlie", "age": 45 }
  ]
}

cat > sample.txt < HERE
$.foo
HERE

jsonfilter -f sample.txt sample.json
{
  "foo": "bar"
}

cat > sample.txt < HERE
$.foo
$.baz
HERE

jsonfilter -f sample.txt sample.json
{
  "foo": "bar",
  "baz": "quux"
}

cat > sample.txt < HERE
$.zip[*].name
HERE

jsonfilter -f sample.txt sample.json
{
  "zip": [
    {
      "name": "alice"
    },
    {
      "name": "bob"
    },
    {
      "name": "charlie"
    }
  ]
}

jsonfilter -r george -f sample.txt sample.json
{
  "zip": [
    {
      "name": "george",
      "age": 22
    },
    {
      "name": "george",
      "age": 16
    },
    {
      "name": "george"
      "age": 45
    }
  ]
}