Subscription.js
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"use strict";
var isArray_1 = require('./util/isArray');
var isObject_1 = require('./util/isObject');
var isFunction_1 = require('./util/isFunction');
var tryCatch_1 = require('./util/tryCatch');
var errorObject_1 = require('./util/errorObject');
var UnsubscriptionError_1 = require('./util/UnsubscriptionError');
/**
* Represents a disposable resource, such as the execution of an Observable. A
* Subscription has one important method, `unsubscribe`, that takes no argument
* and just disposes the resource held by the subscription.
*
* Additionally, subscriptions may be grouped together through the `add()`
* method, which will attach a child Subscription to the current Subscription.
* When a Subscription is unsubscribed, all its children (and its grandchildren)
* will be unsubscribed as well.
*
* @class Subscription
*/
var Subscription = (function () {
/**
* @param {function(): void} [unsubscribe] A function describing how to
* perform the disposal of resources when the `unsubscribe` method is called.
*/
function Subscription(unsubscribe) {
/**
* A flag to indicate whether this Subscription has already been unsubscribed.
* @type {boolean}
*/
this.closed = false;
if (unsubscribe) {
this._unsubscribe = unsubscribe;
}
}
/**
* Disposes the resources held by the subscription. May, for instance, cancel
* an ongoing Observable execution or cancel any other type of work that
* started when the Subscription was created.
* @return {void}
*/
Subscription.prototype.unsubscribe = function () {
var hasErrors = false;
var errors;
if (this.closed) {
return;
}
this.closed = true;
var _a = this, _unsubscribe = _a._unsubscribe, _subscriptions = _a._subscriptions;
this._subscriptions = null;
if (isFunction_1.isFunction(_unsubscribe)) {
var trial = tryCatch_1.tryCatch(_unsubscribe).call(this);
if (trial === errorObject_1.errorObject) {
hasErrors = true;
(errors = errors || []).push(errorObject_1.errorObject.e);
}
}
if (isArray_1.isArray(_subscriptions)) {
var index = -1;
var len = _subscriptions.length;
while (++index < len) {
var sub = _subscriptions[index];
if (isObject_1.isObject(sub)) {
var trial = tryCatch_1.tryCatch(sub.unsubscribe).call(sub);
if (trial === errorObject_1.errorObject) {
hasErrors = true;
errors = errors || [];
var err = errorObject_1.errorObject.e;
if (err instanceof UnsubscriptionError_1.UnsubscriptionError) {
errors = errors.concat(err.errors);
}
else {
errors.push(err);
}
}
}
}
}
if (hasErrors) {
throw new UnsubscriptionError_1.UnsubscriptionError(errors);
}
};
/**
* Adds a tear down to be called during the unsubscribe() of this
* Subscription.
*
* If the tear down being added is a subscription that is already
* unsubscribed, is the same reference `add` is being called on, or is
* `Subscription.EMPTY`, it will not be added.
*
* If this subscription is already in an `closed` state, the passed
* tear down logic will be executed immediately.
*
* @param {TeardownLogic} teardown The additional logic to execute on
* teardown.
* @return {Subscription} Returns the Subscription used or created to be
* added to the inner subscriptions list. This Subscription can be used with
* `remove()` to remove the passed teardown logic from the inner subscriptions
* list.
*/
Subscription.prototype.add = function (teardown) {
if (!teardown || (teardown === Subscription.EMPTY)) {
return Subscription.EMPTY;
}
if (teardown === this) {
return this;
}
var sub = teardown;
switch (typeof teardown) {
case 'function':
sub = new Subscription(teardown);
case 'object':
if (sub.closed || typeof sub.unsubscribe !== 'function') {
break;
}
else if (this.closed) {
sub.unsubscribe();
}
else {
(this._subscriptions || (this._subscriptions = [])).push(sub);
}
break;
default:
throw new Error('unrecognized teardown ' + teardown + ' added to Subscription.');
}
return sub;
};
/**
* Removes a Subscription from the internal list of subscriptions that will
* unsubscribe during the unsubscribe process of this Subscription.
* @param {Subscription} subscription The subscription to remove.
* @return {void}
*/
Subscription.prototype.remove = function (subscription) {
// HACK: This might be redundant because of the logic in `add()`
if (subscription == null || (subscription === this) || (subscription === Subscription.EMPTY)) {
return;
}
var subscriptions = this._subscriptions;
if (subscriptions) {
var subscriptionIndex = subscriptions.indexOf(subscription);
if (subscriptionIndex !== -1) {
subscriptions.splice(subscriptionIndex, 1);
}
}
};
Subscription.EMPTY = (function (empty) {
empty.closed = true;
return empty;
}(new Subscription()));
return Subscription;
}());
exports.Subscription = Subscription;
//# sourceMappingURL=Subscription.js.map