Class Subscription

A set of extension methods exposing query-based sync related functionality over collections.

Inheritance

Object

Subscription

Namespace: Realms.Sync

Assembly: Realm.dll

Syntax

public static class Subscription

Methods

GetAllSubscriptions(Realm)

Returns all subscriptions registered for that Realm.

Declaration

public static IRealmCollection<NamedSubscription> GetAllSubscriptions(this Realm realm)

Parameters

Type	Name	Description
Realm	realm	A Realm opened with a QueryBasedSyncConfiguration.

Returns

Type	Description
IRealmCollection<NamedSubscription>	A queryable collection of all registered subscriptions.

Subscribe<T>(IQueryable<T>, SubscriptionOptions, Expression<Func<T, IQueryable>>[])

For Realms using query-based synchronization, fetches and synchronizes the objects that match the query.

Declaration

public static Subscription<T> Subscribe<T>(this IQueryable<T> query, SubscriptionOptions options = null, params Expression<Func<T, IQueryable>>[] includedBacklinks)

Parameters

Type	Name	Description
IQueryable<T>	query	A query, obtained by calling All<T>() with or without additional filtering applied.
SubscriptionOptions	options	Options that configure some metadata of the subscription, such as its name or time to live.
Expression<Func<T, IQueryable>>[]	includedBacklinks	An array of property expressions which specifies which linkingObjects relationships should be included in the subscription. Subscriptions already include link and list properties (in the forward direction) automatically by default.

Returns

Type	Description
Subscription<T>	A Subscription<T> instance that contains information and methods for monitoring the state of the subscription.

Type Parameters

Name	Description
T	The type of the objects making up the query.

Exceptions

Type	Condition
ArgumentNullException	Thrown if query is null.
ArgumentException	Thrown if the query was not obtained from a query-based synchronized Realm.

Subscribe<T>(IQueryable<T>, String)

For Realms using query-based synchronization, fetches and synchronizes the objects that match the query.

Declaration

[Obsolete("Use Subscribe(query, options) instead.")]
public static Subscription<T> Subscribe<T>(this IQueryable<T> query, string name)

Parameters

Type	Name	Description
IQueryable<T>	query	A query, obtained by calling All<T>() with or without additional filtering applied.
String	name	The name of this query that can be used to unsubscribe from.

Returns

Type	Description
Subscription<T>	A Subscription<T> instance that contains information and methods for monitoring the state of the subscription.

Type Parameters

Name	Description
T	The type of the objects making up the query.

Exceptions

Type	Condition
ArgumentNullException	Thrown if query is null.
ArgumentException	Thrown if the query was not obtained from a query-based synchronized Realm.

UnsubscribeAsync(Realm, String)

Cancel a named subscription that was created by calling Subscribe<T>(IQueryable<T>, SubscriptionOptions, Expression<Func<T, IQueryable>>[]).

Removing a subscription will delete all objects from the local Realm that were matched only by that subscription and not any remaining subscriptions. The deletion is performed by the server, and so has no immediate impact on the contents of the local Realm. If the device is currently offline, the removal will not be processed until the device returns online.

Declaration

public static Task UnsubscribeAsync(this Realm realm, string subscriptionName)

Parameters

Type	Name	Description
Realm	realm	The Realm where this subscription was added.
String	subscriptionName	The name of the subscription to remove.

Returns

Type	Description
Task	An awaitable task, that indicates that the subscription has been removed locally.

UnsubscribeAsync<T>(Subscription<T>)

Cancel a subscription that was created by calling Subscribe<T>(IQueryable<T>, SubscriptionOptions, Expression<Func<T, IQueryable>>[]).

Removing a subscription will delete all objects from the local Realm that were matched only by that subscription and not any remaining subscriptions. The deletion is performed by the server, and so has no immediate impact on the contents of the local Realm. If the device is currently offline, the removal will not be processed until the device returns online.

Declaration

public static Task UnsubscribeAsync<T>(this Subscription<T> subscription)

Parameters

Type	Name	Description
Subscription<T>	subscription	The subscription to cancel.

Returns

Type	Description
Task	An awaitable task, that indicates that the subscription has been removed locally.

Type Parameters

Name	Description
T	The type of the objects that make up the subscription query.