baobab
Version:
JavaScript persistent data tree with cursors.
179 lines (125 loc) • 8.48 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
var _emmett = require('emmett');
var _emmett2 = _interopRequireDefault(_emmett);
var _cursor = require('./cursor');
var _cursor2 = _interopRequireDefault(_cursor);
var _type = require('./type');
var _type2 = _interopRequireDefault(_type);
var _helpers = require('./helpers');
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }
function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; } /**
* Baobab Watchers
* ================
*
* Abstraction used to listen and retrieve data from multiple parts of a
* Baobab tree at once.
*/
/**
* Watcher class.
*
* @constructor
* @param {Baobab} tree - The watched tree.
* @param {object} mapping - A mapping of the paths to watch in the tree.
*/
var Watcher = function (_Emitter) {
_inherits(Watcher, _Emitter);
function Watcher(tree, mapping) {
_classCallCheck(this, Watcher);
// Properties
var _this = _possibleConstructorReturn(this, (Watcher.__proto__ || Object.getPrototypeOf(Watcher)).call(this));
_this.tree = tree;
_this.mapping = null;
_this.state = {
killed: false
};
// Initializing
_this.refresh(mapping);
// Listening
_this.handler = function (e) {
if (_this.state.killed) return;
var watchedPaths = _this.getWatchedPaths();
if ((0, _helpers.solveUpdate)(e.data.paths, watchedPaths)) return _this.emit('update');
};
_this.tree.on('update', _this.handler);
return _this;
}
/**
* Method used to get the current watched paths.
*
* @return {array} - The array of watched paths.
*/
_createClass(Watcher, [{
key: 'getWatchedPaths',
value: function getWatchedPaths() {
var _this2 = this;
var rawPaths = Object.keys(this.mapping).map(function (k) {
var v = _this2.mapping[k];
// Watcher mappings can accept a cursor
if (v instanceof _cursor2.default) return v.solvedPath;
return _this2.mapping[k];
});
return rawPaths.reduce(function (cp, p) {
// Handling path polymorphisms
p = [].concat(p);
// Dynamic path?
if (_type2.default.dynamicPath(p)) p = (0, _helpers.getIn)(_this2.tree._data, p).solvedPath;
if (!p) return cp;
// Facet path?
var monkeyPath = _type2.default.monkeyPath(_this2.tree._monkeys, p);
if (monkeyPath) return cp.concat((0, _helpers.getIn)(_this2.tree._monkeys, monkeyPath).data.relatedPaths());
return cp.concat([p]);
}, []);
}
/**
* Method used to return a map of the watcher's cursors.
*
* @return {object} - TMap of relevant cursors.
*/
}, {
key: 'getCursors',
value: function getCursors() {
var _this3 = this;
var cursors = {};
Object.keys(this.mapping).forEach(function (k) {
var path = _this3.mapping[k];
if (path instanceof _cursor2.default) cursors[k] = path;else cursors[k] = _this3.tree.select(path);
});
return cursors;
}
/**
* Method used to refresh the watcher's mapping.
*
* @param {object} mapping - The new mapping to apply.
* @return {Watcher} - Itself for chaining purposes.
*/
}, {
key: 'refresh',
value: function refresh(mapping) {
if (!_type2.default.watcherMapping(mapping)) throw (0, _helpers.makeError)('Baobab.watch: invalid mapping.', { mapping: mapping });
this.mapping = mapping;
// Creating the get method
var projection = {};
for (var k in mapping) {
projection[k] = mapping[k] instanceof _cursor2.default ? mapping[k].path : mapping[k];
}this.get = this.tree.project.bind(this.tree, projection);
}
/**
* Methods releasing the watcher from memory.
*/
}, {
key: 'release',
value: function release() {
this.tree.off('update', this.handler);
this.state.killed = true;
this.kill();
}
}]);
return Watcher;
}(_emmett2.default);
exports.default = Watcher;