96 lines
2.6 KiB
JavaScript
96 lines
2.6 KiB
JavaScript
"use strict";
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exports.__esModule = true;
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function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
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// encapsulates the subscription logic for connecting a component to the redux store, as
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// well as nesting subscriptions of descendant components, so that we can ensure the
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// ancestor components re-render before descendants
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var CLEARED = null;
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var nullListeners = {
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notify: function notify() {}
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};
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function createListenerCollection() {
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// the current/next pattern is copied from redux's createStore code.
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// TODO: refactor+expose that code to be reusable here?
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var current = [];
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var next = [];
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return {
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clear: function clear() {
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next = CLEARED;
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current = CLEARED;
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},
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notify: function notify() {
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var listeners = current = next;
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for (var i = 0; i < listeners.length; i++) {
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listeners[i]();
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}
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},
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get: function get() {
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return next;
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},
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subscribe: function subscribe(listener) {
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var isSubscribed = true;
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if (next === current) next = current.slice();
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next.push(listener);
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return function unsubscribe() {
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if (!isSubscribed || current === CLEARED) return;
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isSubscribed = false;
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if (next === current) next = current.slice();
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next.splice(next.indexOf(listener), 1);
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};
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}
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};
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}
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var Subscription = function () {
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function Subscription(store, parentSub, onStateChange) {
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_classCallCheck(this, Subscription);
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this.store = store;
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this.parentSub = parentSub;
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this.onStateChange = onStateChange;
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this.unsubscribe = null;
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this.listeners = nullListeners;
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}
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Subscription.prototype.addNestedSub = function addNestedSub(listener) {
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this.trySubscribe();
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return this.listeners.subscribe(listener);
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};
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Subscription.prototype.notifyNestedSubs = function notifyNestedSubs() {
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this.listeners.notify();
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};
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Subscription.prototype.isSubscribed = function isSubscribed() {
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return Boolean(this.unsubscribe);
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};
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Subscription.prototype.trySubscribe = function trySubscribe() {
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if (!this.unsubscribe) {
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this.unsubscribe = this.parentSub ? this.parentSub.addNestedSub(this.onStateChange) : this.store.subscribe(this.onStateChange);
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this.listeners = createListenerCollection();
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}
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};
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Subscription.prototype.tryUnsubscribe = function tryUnsubscribe() {
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if (this.unsubscribe) {
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this.unsubscribe();
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this.unsubscribe = null;
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this.listeners.clear();
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this.listeners = nullListeners;
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}
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};
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return Subscription;
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}();
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exports.default = Subscription; |