AnyRealmCollection
public struct AnyRealmCollection<Element> : RealmCollection where Element : RealmCollectionValue
A type-erased RealmCollection.
Instances of RealmCollection forward operations to an opaque underlying collection having the same Element type.
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The type of the objects contained within the collection.
Declaration
Swift
public typealias ElementType = Element -
Declaration
Swift
public func index(after i: Int) -> Int -
Declaration
Swift
public func index(before i: Int) -> Int -
Creates an
AnyRealmCollectionwrappingbase.Declaration
Swift
public init<C>(_ base: C) where Element == C.Element, C : RealmCollection
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The Realm which manages the collection, or
nilif the collection is unmanaged.Declaration
Swift
public var realm: Realm? { get } -
Indicates if the collection can no longer be accessed.
The collection can no longer be accessed if
invalidate()is called on the containingrealm.Declaration
Swift
public var isInvalidated: Bool { get } -
The number of objects in the collection.
Declaration
Swift
public var count: Int { get } -
A human-readable description of the objects contained in the collection.
Declaration
Swift
public var description: String { get }
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Returns the index of the given object, or
nilif the object is not in the collection.Declaration
Swift
public func index(of object: Element) -> Int?Parameters
objectAn object.
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Returns the index of the first object matching the given predicate, or
nilif no objects match.Declaration
Swift
public func index(matching predicate: NSPredicate) -> Int?Parameters
predicateThe predicate with which to filter the objects.
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Returns the index of the first object matching the given predicate, or
nilif no objects match.Declaration
Swift
public func index(matching predicateFormat: String, _ args: Any...) -> Int?Parameters
predicateFormatA predicate format string, optionally followed by a variable number of arguments.
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Returns a
Resultscontaining all objects matching the given predicate in the collection.Declaration
Swift
public func filter(_ predicate: NSPredicate) -> Results<Element>Parameters
predicateThe predicate with which to filter the objects.
Return Value
A
Resultscontaining objects that match the given predicate.
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Returns a
Resultscontaining the objects in the collection, but sorted.Objects are sorted based on the values of the given key path. For example, to sort a collection of
Students from youngest to oldest based on theirageproperty, you might callstudents.sorted(byKeyPath: "age", ascending: true).Warning
Collections may only be sorted by properties of boolean,
Date,NSDate, single and double-precision floating point, integer, and string types.Declaration
Swift
public func sorted(byKeyPath keyPath: String, ascending: Bool) -> Results<Element>Parameters
keyPathThe key path to sort by.
ascendingThe direction to sort in.
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Returns a
Resultscontaining the objects in the collection, but sorted.Warning
Collections may only be sorted by properties of boolean,
Date,NSDate, single and double-precision floating point, integer, and string types.Declaration
Swift
public func sorted<S: Sequence>(by sortDescriptors: S) -> Results<Element> where S.Iterator.Element == SortDescriptorParameters
sortDescriptorsA sequence of
SortDescriptors to sort by.
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Returns the minimum (lowest) value of the given property among all the objects in the collection, or
nilif the collection is empty.Warning
Only a property whose type conforms to the
MinMaxTypeprotocol can be specified.Declaration
Swift
public func min<T>(ofProperty property: String) -> T? where T : MinMaxTypeParameters
propertyThe name of a property whose minimum value is desired.
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Returns the maximum (highest) value of the given property among all the objects in the collection, or
nilif the collection is empty.Warning
Only a property whose type conforms to the
MinMaxTypeprotocol can be specified.Declaration
Swift
public func max<T>(ofProperty property: String) -> T? where T : MinMaxTypeParameters
propertyThe name of a property whose minimum value is desired.
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Returns the sum of the values of a given property over all the objects in the collection.
Warning
Only a property whose type conforms to the
AddableTypeprotocol can be specified.Declaration
Swift
public func sum<T>(ofProperty property: String) -> T where T : AddableTypeParameters
propertyThe name of a property whose values should be summed.
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Returns the average value of a given property over all the objects in the collection, or
nilif the collection is empty.Warning
Only the name of a property whose type conforms to the
AddableTypeprotocol can be specified.Declaration
Swift
public func average(ofProperty property: String) -> Double?Parameters
propertyThe name of a property whose average value should be calculated.
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Returns the object at the given
index.Declaration
Swift
public subscript(position: Int) -> Element { get }Parameters
indexThe index.
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Returns a
RLMIteratorthat yields successive elements in the collection.Declaration
Swift
public func makeIterator() -> RLMIterator<Element>
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The position of the first element in a non-empty collection. Identical to endIndex in an empty collection.
Declaration
Swift
public var startIndex: Int { get } -
The collection’s
past the end
position. endIndex is not a valid argument to subscript, and is always reachable from startIndex by zero or more applications of successor().Declaration
Swift
public var endIndex: Int { get }
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Returns an
Arraycontaining the results of invokingvalueForKey(_:)withkeyon each of the collection’s objects.Declaration
Swift
public func value(forKey key: String) -> Any?Parameters
keyThe name of the property whose values are desired.
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Returns an
Arraycontaining the results of invokingvalueForKeyPath(_:)withkeyPathon each of the collection’s objects.Declaration
Swift
public func value(forKeyPath keyPath: String) -> Any?Parameters
keyPathThe key path to the property whose values are desired.
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Invokes
setValue(_:forKey:)on each of the collection’s objects using the specifiedvalueandkey.Warning
This method may only be called during a write transaction.
Declaration
Swift
public func setValue(_ value: Any?, forKey key: String)Parameters
valueThe value to set the property to.
keyThe name of the property whose value should be set on each object.
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Registers a block to be called each time the collection changes.
The block will be asynchronously called with the initial results, and then called again after each write transaction which changes either any of the objects in the collection, or which objects are in the collection.
The
changeparameter that is passed to the block reports, in the form of indices within the collection, which of the objects were added, removed, or modified during each write transaction. See theRealmCollectionChangedocumentation for more information on the change information supplied and an example of how to use it to update aUITableView.At the time when the block is called, the collection will be fully evaluated and up-to-date, and as long as you do not perform a write transaction on the same thread or explicitly call
realm.refresh(), accessing it will never perform blocking work.Notifications are delivered via the standard run loop, and so can’t be delivered while the run loop is blocked by other activity. When notifications can’t be delivered instantly, multiple notifications may be coalesced into a single notification. This can include the notification with the initial collection.
For example, the following code performs a write transaction immediately after adding the notification block, so there is no opportunity for the initial notification to be delivered first. As a result, the initial notification will reflect the state of the Realm after the write transaction.
let results = realm.objects(Dog.self) print("dogs.count: \(dogs?.count)") // => 0 let token = dogs.observe { changes in switch changes { case .initial(let dogs): // Will print "dogs.count: 1" print("dogs.count: \(dogs.count)") break case .update: // Will not be hit in this example break case .error: break } } try! realm.write { let dog = Dog() dog.name = "Rex" person.dogs.append(dog) } // end of run loop execution contextYou must retain the returned token for as long as you want updates to be sent to the block. To stop receiving updates, call
invalidate()on the token.Warning
This method cannot be called during a write transaction, or when the containing Realm is read-only.
Declaration
Swift
public func observe(_ block: @escaping (RealmCollectionChange<AnyRealmCollection>) -> Void) -> NotificationTokenParameters
blockThe block to be called whenever a change occurs.
Return Value
A token which must be held for as long as you want updates to be delivered.
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AnyRealmCollection Structure Reference