Key-Value Observing
E427885
Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
All labels observed (5)
| Label | Occurrences |
|---|---|
| KVO | 1 |
| KVO (Key-Value Observing) | 1 |
| Key-Value Observing canonical | 1 |
| Key-Value Observing Programming Guide | 1 |
| NSKeyValueObservation | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4275594 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Key-Value Observing Context triple: [Combine, integratesWith, Key-Value Observing]
-
A.
NSObject
NSObject is the root base class in Objective-C from which most classes in Cocoa and Cocoa Touch inherit, providing fundamental object behavior such as memory management and message sending.
-
B.
Objective-C
Objective-C is an object-oriented programming language primarily known for its use in developing software for Apple's macOS and iOS platforms.
-
C.
Core Animation
Core Animation is Apple’s high-performance graphics rendering and animation framework used to create smooth, hardware-accelerated visual effects in macOS, iOS, and other Apple platforms.
-
D.
Grand Central Dispatch
Grand Central Dispatch is Apple's low-level concurrency and task scheduling framework used to efficiently manage parallel execution of code on macOS, iOS, and other Darwin-based systems.
-
E.
Objective-C runtime
Objective-C runtime is the dynamic library and infrastructure that enables Objective-C’s message passing, dynamic typing, and introspection features at program execution time.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Key-Value Observing Target entity description: Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
-
A.
NSObject
NSObject is the root base class in Objective-C from which most classes in Cocoa and Cocoa Touch inherit, providing fundamental object behavior such as memory management and message sending.
-
B.
Objective-C
Objective-C is an object-oriented programming language primarily known for its use in developing software for Apple's macOS and iOS platforms.
-
C.
Core Animation
Core Animation is Apple’s high-performance graphics rendering and animation framework used to create smooth, hardware-accelerated visual effects in macOS, iOS, and other Apple platforms.
-
D.
Grand Central Dispatch
Grand Central Dispatch is Apple's low-level concurrency and task scheduling framework used to efficiently manage parallel execution of code on macOS, iOS, and other Darwin-based systems.
-
E.
Objective-C runtime
Objective-C runtime is the dynamic library and infrastructure that enables Objective-C’s message passing, dynamic typing, and introspection features at program execution time.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
Objective-C feature
ⓘ
Swift feature ⓘ observer pattern implementation ⓘ |
| alsoKnownAs |
KVO
ⓘ
linked to:
Key-Value Observing
|
| AppleDocumentationTopic |
Key-Value Observing Programming Guide
ⓘ
linked to:
Key-Value Observing
|
| basedOn | Key-Value Coding ⓘ |
| canObserve |
Objective-C properties
ⓘ
Swift properties exposed to Objective-C ⓘ |
| changeType |
NSKeyValueChange.insertion
ⓘ
NSKeyValueChange.removal ⓘ NSKeyValueChange.replacement ⓘ NSKeyValueChange.setting ⓘ |
| collectionProxyClass |
NSKeyValueArray
ⓘ
NSKeyValueOrderedSet ⓘ NSKeyValueSet ⓘ
linked to:
NSMutableSet
|
| commonIssue |
crashes from dangling observers
ⓘ
over-observation of frequently changing properties ⓘ |
| coreConcept |
change dictionary
ⓘ
key path ⓘ observation context ⓘ observed object ⓘ observer object ⓘ |
| definedInFramework | Foundation framework ⓘ |
| improvedIn | Swift block-based API ⓘ |
| introducedIn | Cocoa ⓘ |
| notificationMethod | observeValueForKeyPath:ofObject:change:context: ⓘ |
| platform |
iOS
ⓘ
macOS ⓘ tvOS ⓘ watchOS ⓘ |
| primaryPurpose |
notify observers of value changes
ⓘ
observe property changes ⓘ |
| relatedConcept |
Combine framework
ⓘ
linked to:
Combine
NotificationCenter ⓘ
linked to:
NSNotificationCenter
delegation pattern ⓘ |
| requires | KVC-compliant properties ⓘ |
| requiresCareWith | observer lifetime management ⓘ |
| supportsCollectionObserving | to-many relationships ⓘ |
| supportsFeature |
automatic notifications for property changes
ⓘ
manual notifications for property changes ⓘ |
| SwiftAPI |
KeyPath-based observing
ⓘ
NSKeyValueObservation ⓘ
linked to:
Key-Value Observing
|
| typicalUseCase |
data binding
ⓘ
model-view synchronization ⓘ reactive UI updates ⓘ |
| usedInLanguage |
Objective-C
ⓘ
Swift ⓘ |
| usesMechanism | Objective-C runtime ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Key-Value Observing Description of subject: Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Key-Value Observing
linked to: Key-Value Observing
linked to: Key-Value Observing
linked to: Key-Value Observing