observable-set/has.js

Configure observable set collections

'use strict';

var d                 = require('d')
  , memoize           = require('memoizee/plain')
  , memoizeMethods    = require('memoizee/methods-plain')
  , getNormalizer     = require('memoizee/normalizers/get-1')
  , isObservable      = require('observable-value/is-observable-value')
  , ReadOnly          = require('observable-value/create-read-only')(require('observable-value'))
  , validObservableSet = require('./valid-observable-set')

  , defineProperties = Object.defineProperties;

module.exports = memoize(function (prototype) {
	validObservableSet(prototype);

	return defineProperties(prototype, memoizeMethods({
		_has: d(function (value) {
			var result, onChange;
			if (isObservable(value)) {
				result = new ReadOnly(this.has(value.value));
				this.on('change', onChange = function () { result._setValue(this.has(value.value)); });
				value.on('change', onChange);
			} else {
				result = new ReadOnly(this.has(value));
				this.on('change', function () { result._setValue(this.has(value)); });
			}
			return result;
		}, { getNormalizer: getNormalizer })
	}));
}, { normalizer: getNormalizer() });