AnyRealmCollection
public final class AnyRealmCollection<T: Object>: RealmCollectionType
A type-erased RealmCollectionType
.
Instances of RealmCollectionType
forward operations to an opaque underlying collection having the same Element
type.
-
The type of the objects contained in the collection.
Declaration
Swift
public typealias Element = T
-
Returns the object at the given
index
.Declaration
Swift
public subscript(index: Int) -> T { return base[index] }
Parameters
index
The index.
Return Value
The object at the given
index
. -
Creates an
AnyRealmCollection
wrappingbase
.Declaration
Swift
public init<C: RealmCollectionType where C.Element == T>(_ base: C)
-
The Realm which manages this collection, or
nil
if the collection is unmanaged.Declaration
Swift
public var realm: Realm?
-
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 invalidated: Bool
-
The number of objects in the collection.
Declaration
Swift
public var count: Int
-
A human-readable description of the objects contained in the collection.
Declaration
Swift
public var description: String
-
Returns the index of the given object, or
nil
if the object is not in the collection.Declaration
Swift
public func indexOf(object: Element) -> Int?
Parameters
object
An object.
-
Returns the index of the first object matching the given predicate, or
nil
if no objects match.Declaration
Swift
public func indexOf(predicate: NSPredicate) -> Int?
Parameters
predicate
The predicate with which to filter the objects.
-
Returns the index of the first object matching the given predicate, or
nil
if no objects match.Declaration
Swift
public func indexOf(predicateFormat: String, _ args: AnyObject...) -> Int?
Parameters
predicateFormat
A predicate format string, optionally followed by a variable number of arguments.
-
Returns a
Results
containing all objects matching the given predicate in the collection.Declaration
Parameters
predicateFormat
A predicate format string, optionally followed by a variable number of arguments.
-
Returns a
Results
containing the objects in the collection, but sorted.Objects are sorted based on the values of the given property. For example, to sort a collection of
Student
s from youngest to oldest based on theirage
property, you might callstudents.sorted("age", ascending: true)
.Warning
Collections may only be sorted by properties of boolean,
NSDate
, single and double-precision floating point, integer, and string types.Parameters
property
The name of the property to sort by.
ascending
The direction to sort in.
-
Returns a
Results
containing the objects in the collection, but sorted.Warning
Collections may only be sorted by properties of boolean,
NSDate
, single and double-precision floating point, integer, and string types.Declaration
Swift
public func sorted<S: SequenceType where S.Generator.Element == SortDescriptor> (sortDescriptors: S) -> Results<Element>
Parameters
sortDescriptors
A sequence of
SortDescriptor
s to sort by.
-
Returns the minimum (lowest) value of the given property among all the objects represented by the collection.
Warning
Only a property whose type conforms to the
MinMaxType
protocol can be specified.Declaration
Swift
public func min<U: MinMaxType>(property: String) -> U?
Parameters
property
The name of a property whose minimum value is desired.
Return Value
The minimum value of the property, or
nil
if the collection is empty. -
Returns the maximum (highest) value of the given property among all the objects represented by the collection.
Warning
Only a property whose type conforms to the
MinMaxType
protocol can be specified.Declaration
Swift
public func max<U: MinMaxType>(property: String) -> U?
Parameters
property
The name of a property whose minimum value is desired.
Return Value
The maximum value of the property, or
nil
if the collection is empty. -
Returns the sum of the values of a given property over all the objects represented by the collection.
Warning
Only a property whose type conforms to the
AddableType
protocol can be specified.Declaration
Swift
public func sum<U: AddableType>(property: String) -> U
Parameters
property
The name of a property whose values should be summed.
Return Value
The sum of the given property.
-
Returns the average value of a given property over all the objects represented by the collection.
Warning
Only the name of a property whose type conforms to the
AddableType
protocol can be specified.Declaration
Swift
public func average<U: AddableType>(property: String) -> U?
Parameters
property
The name of a property whose average value should be calculated.
Return Value
The average value of the given property, or
nil
if the collection is empty.
-
Returns an
RLMGenerator
that yields successive elements in the collection.Declaration
Swift
public func generate() -> RLMGenerator<T>
-
The position of the first element in a non-empty collection. Identical to
endIndex
in an empty collection.Declaration
Swift
public var startIndex: Int
-
The collection’s
past the end
position.endIndex
is not a valid argument tosubscript
, and is always reachable fromstartIndex
by zero or more applications ofsuccessor()
.Declaration
Swift
public var endIndex: Int
-
Returns an
Array
containing the results of invokingvalueForKey(_:)
withkey
on each of the collection’s objects.Declaration
Swift
public func valueForKey(key: String) -> AnyObject?
Parameters
key
The name of the property whose values are desired.
Return Value
An
Array
containing the results. -
Returns an
Array
containing the results of invokingvalueForKeyPath(_:)
withkeyPath
on each of the collection’s objects.Declaration
Swift
public func valueForKeyPath(keyPath: String) -> AnyObject?
Parameters
keyPath
The key path to the property whose values are desired.
Return Value
An
Array
containing the results. -
Invokes
setValue(_:forKey:)
on each of the collection’s objects using the specifiedvalue
andkey
.Warning
This method may only be called during a write transaction.
Declaration
Swift
public func setValue(value: AnyObject?, forKey key: String)
Parameters
value
The value to set the property to.
key
The name of the property whose value should be set on each object.
-
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
change
parameter 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 theRealmCollectionChange
documentation 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.addNotificationBlock { 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 context
You must retain the returned token for as long as you want updates to be sent to the block. To stop receiving updates, call
stop()
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 addNotificationBlock(block: (RealmCollectionChange<AnyRealmCollection>) -> ()) -> NotificationToken
Parameters
block
The block to be called whenever a change occurs.
Return Value
A token which must be retained for as long as you want updates to be delivered.