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4.42 kBTypeScriptView Raw
1import { SubscriptionLike, TeardownLogic } from './types';
2/**
3 * Represents a disposable resource, such as the execution of an Observable. A
4 * Subscription has one important method, `unsubscribe`, that takes no argument
5 * and just disposes the resource held by the subscription.
6 *
7 * Additionally, subscriptions may be grouped together through the `add()`
8 * method, which will attach a child Subscription to the current Subscription.
9 * When a Subscription is unsubscribed, all its children (and its grandchildren)
10 * will be unsubscribed as well.
11 *
12 * @class Subscription
13 */
14export declare class Subscription implements SubscriptionLike {
15 private initialTeardown?;
16 /** @nocollapse */
17 static EMPTY: Subscription;
18 /**
19 * A flag to indicate whether this Subscription has already been unsubscribed.
20 */
21 closed: boolean;
22 private _parentage;
23 /**
24 * The list of registered finalizers to execute upon unsubscription. Adding and removing from this
25 * list occurs in the {@link #add} and {@link #remove} methods.
26 */
27 private _finalizers;
28 /**
29 * @param initialTeardown A function executed first as part of the finalization
30 * process that is kicked off when {@link #unsubscribe} is called.
31 */
32 constructor(initialTeardown?: (() => void) | undefined);
33 /**
34 * Disposes the resources held by the subscription. May, for instance, cancel
35 * an ongoing Observable execution or cancel any other type of work that
36 * started when the Subscription was created.
37 * @return {void}
38 */
39 unsubscribe(): void;
40 /**
41 * Adds a finalizer to this subscription, so that finalization will be unsubscribed/called
42 * when this subscription is unsubscribed. If this subscription is already {@link #closed},
43 * because it has already been unsubscribed, then whatever finalizer is passed to it
44 * will automatically be executed (unless the finalizer itself is also a closed subscription).
45 *
46 * Closed Subscriptions cannot be added as finalizers to any subscription. Adding a closed
47 * subscription to a any subscription will result in no operation. (A noop).
48 *
49 * Adding a subscription to itself, or adding `null` or `undefined` will not perform any
50 * operation at all. (A noop).
51 *
52 * `Subscription` instances that are added to this instance will automatically remove themselves
53 * if they are unsubscribed. Functions and {@link Unsubscribable} objects that you wish to remove
54 * will need to be removed manually with {@link #remove}
55 *
56 * @param teardown The finalization logic to add to this subscription.
57 */
58 add(teardown: TeardownLogic): void;
59 /**
60 * Checks to see if a this subscription already has a particular parent.
61 * This will signal that this subscription has already been added to the parent in question.
62 * @param parent the parent to check for
63 */
64 private _hasParent;
65 /**
66 * Adds a parent to this subscription so it can be removed from the parent if it
67 * unsubscribes on it's own.
68 *
69 * NOTE: THIS ASSUMES THAT {@link _hasParent} HAS ALREADY BEEN CHECKED.
70 * @param parent The parent subscription to add
71 */
72 private _addParent;
73 /**
74 * Called on a child when it is removed via {@link #remove}.
75 * @param parent The parent to remove
76 */
77 private _removeParent;
78 /**
79 * Removes a finalizer from this subscription that was previously added with the {@link #add} method.
80 *
81 * Note that `Subscription` instances, when unsubscribed, will automatically remove themselves
82 * from every other `Subscription` they have been added to. This means that using the `remove` method
83 * is not a common thing and should be used thoughtfully.
84 *
85 * If you add the same finalizer instance of a function or an unsubscribable object to a `Subscription` instance
86 * more than once, you will need to call `remove` the same number of times to remove all instances.
87 *
88 * All finalizer instances are removed to free up memory upon unsubscription.
89 *
90 * @param teardown The finalizer to remove from this subscription
91 */
92 remove(teardown: Exclude<TeardownLogic, void>): void;
93}
94export declare const EMPTY_SUBSCRIPTION: Subscription;
95export declare function isSubscription(value: any): value is Subscription;
96//# sourceMappingURL=Subscription.d.ts.map
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