parse-js/dist/transformers/switch.js

Utility library for object structure conversion.

'use strict';

var _get = require('lodash/get');

var _isNil = require('lodash/isNil');

var _isFunction = require('lodash/isFunction');

var nullSelector = {
  parse: function parse() {},
  reverse: function reverse() {}
};

function wrapPath(selector) {
  if (_isFunction(selector)) return selector;
  if (_isNil(selector)) return selector;
  return function (source) {
    return _get(source, selector);
  };
}

function SwitchTransformer() {
  var cases = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
  var parseSelector = arguments.length > 1 ? arguments[1] : undefined;
  var reverseSelector = arguments.length > 2 ? arguments[2] : undefined;

  if (!(this instanceof SwitchTransformer)) {
    return this.transform(new SwitchTransformer(cases, parseSelector, reverseSelector));
  }

  this._cases = cases;
  this._parseSelector = wrapPath(parseSelector);
  this._reverseSelector = wrapPath(reverseSelector);
}

SwitchTransformer.prototype._getParser = function (source, root, selector) {
  if (!selector) return nullSelector;
  var value = selector(source, root);
  var next = this._cases[value];
  if (next) return next;
  return this._cases['_default_'];
};

SwitchTransformer.prototype.parse = function (source, instance, root) {
  var next = this._getParser(source, root, this._parseSelector);

  if (!next || !_isFunction(next.parse)) return void 0;
  return next.parse(source, instance, root);
};

SwitchTransformer.prototype.reverse = function (source, instance, root) {
  var next = this._getParser(source, root, this._reverseSelector);

  if (!next || !_isFunction(next.reverse)) return void 0;
  return next.reverse(source, instance, root);
};

module.exports = SwitchTransformer;