object-scan

Object-Scan

Find Keys using Wildcard matching and optional value function.

Install

Install with npm:

$ npm install --save object-scan

Usage

const objectScan = require('object-scan');

objectScan(["a.*.f"])({ a: { b: { c: 'd' }, e: { f: 'g' } } });
// => [ 'a.e.f' ]

Options

filterFn

Type: function
Default: undefined

Takes arguments key (dot joined and escaped) and value (value for given key) and called for every potential result. If function is defined and returns false, the entry is filtered from the result.

breakFn

Type: function
Default: undefined

Takes arguments key (dot joined and escaped) and value (value for given key) and called for every potential result. If function is defined and returns true, no nested entries are checked.

joined

Type: boolean
Default: true

Can be set to false to return each key as a list. When dealing with special characters this can be useful.

Examples

More extensive examples can be found in the tests.

const objectScan = require('object-scan');

const obj = {
  a: {
    b: {
      c: 'd'
    },
    e: {
      f: 'g'
    },
    h: ["i", "j"]
  },
  k: "l"
};

// top level keys
objectScan(["*"])(obj);
// => ["a", "k"]

// nested keys
objectScan(["a.*.f"])(obj);
// => ["a.e.f"]
objectScan(["*.*.*"])(obj);
// => ["a.b.c", "a.e.f"]

// or filter
objectScan(["a.*.{c,f}"])(obj);
// => ["a.b.c", "a.e.f"]
objectScan(["a.*.{c,f}"], { joined: false })(obj);
// => [["a", "b", "c"], ["a", "e", "f"]]

// list filter
objectScan(["*.*[*]"])(obj);
// => ["a.h[0]", "a.h[1]"]
objectScan(["*[*]"])(obj);
// => []

// deep star filter
objectScan(["**"])(obj);
// => ["a", "a.b", "a.b.c", "a.e", "a.e.f", "a.h", "a.h[0]", "a.h[1]", "k"]
objectScan(["**.f"])(obj);
// => ["a.e.f"]
objectScan(["**[*]"])(obj);
// => ["a.h[0]", "a.h[1]"]

// value function
objectScan(["**"], { filterFn: (key, value) => typeof value === "string" })(obj);
// => ["a.b.c", "a.e.f", "a.h[0]", "a.h[1]", "k"]
objectScan(["**"], { breakFn: key => key === "a.b" })(obj);
// => ["a", "a.b", "a.e", "a.e.f", "a.h", "a.h[0]", "a.h[1]", "k"]);

Special Characters

The following Characters are considered special and need to be escaped if they should be matched in a key: [, ], {, }, ,, . and *.

When dealing with special characters the joined option might be desirable to set to false.