1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/addon-sdk/source/lib/sdk/util/contract.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,51 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +"use strict";
1.9 +
1.10 +module.metadata = {
1.11 + "stability": "unstable"
1.12 +};
1.13 +
1.14 +const { validateOptions: valid } = require("../deprecated/api-utils");
1.15 +
1.16 +// Function takes property validation rules and returns function that given
1.17 +// an `options` object will return validated / normalized options back. If
1.18 +// option(s) are invalid validator will throw exception described by rules.
1.19 +// Returned will also have contain `rules` property with a given validation
1.20 +// rules and `properties` function that can be used to generate validated
1.21 +// property getter and setters can be mixed into prototype. For more details
1.22 +// see `properties` function below.
1.23 +function contract(rules) {
1.24 + function validator(options) {
1.25 + return valid(options || {}, rules);
1.26 + }
1.27 + validator.rules = rules
1.28 + validator.properties = function(modelFor) {
1.29 + return properties(modelFor, rules);
1.30 + }
1.31 + return validator;
1.32 +}
1.33 +exports.contract = contract
1.34 +
1.35 +// Function takes `modelFor` instance state model accessor functions and
1.36 +// a property validation rules and generates object with getters and setters
1.37 +// that can be mixed into prototype. Property accessors update model for the
1.38 +// given instance. If you wish to react to property updates you can always
1.39 +// override setters to put specific logic.
1.40 +function properties(modelFor, rules) {
1.41 + let descriptor = Object.keys(rules).reduce(function(descriptor, name) {
1.42 + descriptor[name] = {
1.43 + get: function() { return modelFor(this)[name] },
1.44 + set: function(value) {
1.45 + let change = {};
1.46 + change[name] = value;
1.47 + modelFor(this)[name] = valid(change, rules)[name];
1.48 + }
1.49 + }
1.50 + return descriptor
1.51 + }, {});
1.52 + return Object.create(Object.prototype, descriptor);
1.53 +}
1.54 +exports.properties = properties
