AnyRealmCollection
public final class AnyRealmCollection<T: Object>: RealmCollectionType
A type-erased RealmCollectionType
.
Forwards operations to an arbitrary underlying collection having the same
Element type, hiding the specifics of the underlying RealmCollectionType
.
-
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
. -
Element type contained in this collection.
Declaration
Swift
public typealias Element = T
-
Creates an AnyRealmCollection wrapping
base
.Declaration
Swift
public init<C: RealmCollectionType where C.Element == T>(_ base: C)
-
The Realm the objects in this collection belong to, or
nil
if the collection’s owning object does not belong to a realm (the collection is standalone).Declaration
Swift
public var realm: Realm? { return base.realm }
-
Returns the number of objects in this collection.
Declaration
Swift
public var count: Int { return base.count }
-
Returns a human-readable description of the objects contained in this collection.
Declaration
Swift
public var description: String { return base.description }
-
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? { return base.indexOf(object) }
Parameters
object
The object whose index is being queried.
Return Value
The index of the given object, or
nil
if the object is not in the collection. -
Returns the index of the first object matching the given predicate, or
nil
no objects match.Declaration
Swift
public func indexOf(predicate: NSPredicate) -> Int? { return base.indexOf(predicate) }
Parameters
predicate
The
NSPredicate
used to filter the objects.Return Value
The index of the first matching object, or
nil
if no objects match. -
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
The predicate format string, optionally followed by a variable number of arguments.
Return Value
The index of the first matching object, or
nil
if no objects match.
-
Returns
Results
containing collection elements that match the given predicate.Declaration
Swift
public func filter(predicateFormat: String, _ args: AnyObject...) -> Results<Element>
Parameters
predicateFormat
The predicate format string which can accept variable arguments.
Return Value
Results
containing collection elements that match the given predicate. -
Returns
Results
containing collection elements that match the given predicate.Declaration
Swift
public func filter(predicate: NSPredicate) -> Results<Element> { return base.filter(predicate) }
Parameters
predicate
The predicate to filter the objects.
Return Value
Results
containing collection elements that match the given predicate.
-
Returns
Results
containing collection elements sorted by the given property.Declaration
Swift
public func sorted(property: String, ascending: Bool) -> Results<Element>
Parameters
property
The property name to sort by.
ascending
The direction to sort by.
Return Value
Results
containing collection elements sorted by the given property. -
Returns
Results
with elements sorted by the given sort descriptors.Declaration
Swift
public func sorted<S: SequenceType where S.Generator.Element == SortDescriptor> (sortDescriptors: S) -> Results<Element>
Parameters
sortDescriptors
SortDescriptor
s to sort by.Return Value
Results
with elements sorted by the given sort descriptors.
-
Returns the minimum value of the given property.
Warning
Only names of properties of a type conforming to the
MinMaxType
protocol can be used.Declaration
Swift
public func min<U: MinMaxType>(property: String) -> U? { return base.min(property) }
Parameters
property
The name of a property conforming to
MinMaxType
to look for a minimum on.Return Value
The minimum value for the property amongst objects in the collection, or
nil
if the collection is empty. -
Returns the maximum value of the given property.
Warning
Only names of properties of a type conforming to the
MinMaxType
protocol can be used.Declaration
Swift
public func max<U: MinMaxType>(property: String) -> U? { return base.max(property) }
Parameters
property
The name of a property conforming to
MinMaxType
to look for a maximum on.Return Value
The maximum value for the property amongst objects in the collection, or
nil
if the collection is empty. -
Returns the sum of the given property for objects in the collection.
Warning
Only names of properties of a type conforming to the
AddableType
protocol can be used.Declaration
Swift
public func sum<U: AddableType>(property: String) -> U { return base.sum(property) }
Parameters
property
The name of a property conforming to
AddableType
to calculate sum on.Return Value
The sum of the given property over all objects in the collection.
-
Returns the average of the given property for objects in the collection.
Warning
Only names of properties of a type conforming to the
AddableType
protocol can be used.Declaration
Swift
public func average<U: AddableType>(property: String) -> U? { return base.average(property) }
Parameters
property
The name of a property conforming to
AddableType
to calculate average on.Return Value
The average of the given property over all objects in the collection, or
nil
if the collection is empty.
-
Returns a
GeneratorOf<T>
that yields successive elements in the collection.Declaration
Swift
public func generate() -> RLMGenerator<T> { return base.generate() }
-
The position of the first element in a non-empty collection. Identical to endIndex in an empty collection.
Declaration
Swift
public var startIndex: Int { return base.startIndex }
-
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 { return base.endIndex }
-
Returns an Array containing the results of invoking
valueForKey(_:)
using key on each of the collection’s objects.Declaration
Swift
public func valueForKey(key: String) -> AnyObject? { return base.valueForKey(key) }
Parameters
key
The name of the property.
Return Value
Array containing the results of invoking
valueForKey(_:)
using key on each of the collection’s objects. -
Returns an Array containing the results of invoking
valueForKeyPath(_:)
using keyPath on each of the collection’s objects.Declaration
Swift
public func valueForKeyPath(keyPath: String) -> AnyObject? { return base.valueForKeyPath(keyPath) }
Parameters
keyPath
The key path to the property.
Return Value
Array containing the results of invoking
valueForKeyPath(_:)
using keyPath on each of the collection’s objects. -
Invokes
setValue(_:forKey:)
on each of the collection’s objects using the specified value and key.Warning
This method can only be called during a write transaction.
Declaration
Swift
public func setValue(value: AnyObject?, forKey key: String) { base.setValue(value, forKey: key) }
Parameters
value
The object value.
key
The name of the property.
-
Register a block to be called each time the collection changes.
The block will be asynchronously called with the initial collection, and then called again after each write transaction which changes the collection or any of the items in the collection.
The block is called on the same thread as it was added on, and can only be added on threads which are currently within a run loop. Unless you are specifically creating and running a run loop on a background thread, this normally will only be the main thread.
Notifications can’t be delivered as long as the runloop is blocked by other activity. When notifications can’t be delivered instantly, multiple notifications may be coalesced. That can include the notification about the initial collection.
You must retain the returned token for as long as you want updates to continue to be sent to the block. To stop receiving updates, call stop() on the token.
Declaration
Swift
public func addNotificationBlock(block: (collection: AnyRealmCollection<Element>?, error: NSError?) -> ()) -> NotificationToken
Parameters
block
The block to be called each time the collection changes.
Return Value
A token which must be held for as long as you want notifications to be delivered.
-
Register 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.
At the time when the block is called, the collection object 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) print("dogs.count: \(dogs?.count)") // => 0 let token = dogs.addNotificationBlock { (changes: RealmCollectionChange) 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 continue 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 source realm is read-only.
Declaration
Swift
public func addNotificationBlock(block: (RealmCollectionChange<AnyRealmCollection>) -> ()) -> NotificationToken { return base._addNotificationBlock(block) }
Parameters
block
The block to be called with the evaluated collection and change information.
Return Value
A token which must be held for as long as you want updates to be delivered.