Extract from a JS object with a specific pattern

README.md

extractWithPattern

Extract from a JS object with a specific pattern

let msg = [
	{ payload: { errors: { unknown_language: 'hello' } } },
	{ payload: { errors: { number: 1 } } },
	{ randomstuff: 42 }
];

// "hello"
extractWithPattern(msg, '[].payload.errors.unknown_language');

// 42
extractWithPattern(msg, '[].randomstuff');

extractWithPattern.js

function extractWithPattern(input, pattern) {
	if (input == null) return null;
	if (pattern == '') return input;

	const p = pattern.split('.');
	let _p = p.shift();

	// Array search
	if (_p === '[]') {
		_p = p.shift();
		for (let _input of input) {
			if (_input[_p] != null) {
				const found = extractWithPattern(_input[_p], p.join('.'));
				if (found) return found;
			}
		}
		return null;
	}

	if (p.length === 0) {
		return input[_p];
	}

	return extractWithPattern(input[_p], p.join('.'));
}