PMKVObserver alternatives and similar libraries
Based on the "Events" category.
Alternatively, view PMKVObserver alternatives based on common mentions on social networks and blogs.
-
OpenCombine
Open source implementation of Apple's Combine framework for processing values over time. -
Tokamak
DISCONTINUED. SwiftUI-compatible framework for building browser apps with WebAssembly and native apps for other platforms [Moved to: https://github.com/TokamakUI/Tokamak] -
Katana
DISCONTINUED. Swift Apps in a Swoosh! A modern framework for creating iOS apps, inspired by Redux. -
VueFlux
:recycle: Unidirectional State Management Architecture for Swift - Inspired by Vuex and Flux -
LightweightObservable
📬 A lightweight implementation of an observable sequence that you can subscribe to. -
RxReduce
DISCONTINUED. Reactive implementation of the state container pattern (like Redux). It is based on the simple concepts of state immutability and unidirectionnal data flow. -
TopicEventBus
Publish–subscribe design pattern implementation framework, with an ability to publish events by topic. -
Causality
A simple thread-safe, in-memory bus for Swift that supports fully-typed Events and States.
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README
PMKVObserver
PMKVObserver provides a safe block-based wrapper around Key-Value Observing, with APIs for both Obj-C and Swift. Features include:
- Thread-safety. Observers can be registered on a different thread than KVO notifications are sent on, and can be cancelled on yet another thread. An observer can even be cancelled from two threads simultaneously.
- Automatic unregistering when the observed object deallocates.
- Note: nested key paths are not supported at this time and manual cancellation should be used; more info here
- Support for providing an observing object that is given to the block, and automatic unregistering when this observing object deallocates. This lets you call methods on
self
without retaining it or dealing with a weak reference. - Thread-safety for the automatic deallocation. This protects against receiving messages on another thread while the object is deallocating.
- First-class support for both Obj-C and Swift, including strong typing in the Swift API.
Examples
Swift
// Observe an object for as long as the object is alive.
_ = KVObserver(object: user, keyPath: \User.fullName) { object, _, _ in
// `object` has the same type as `user`
print("User's full name changed to \(object.fullName)")
}
// Convenience methods for working with the change dictionary
_ = KVObserver(object: user, keyPath: \User.fullName, options: [.old, .new]) { _, change, _ in
// unfortunately we don't know what the type of fullName is, so change uses Any
let old = change.old as? String
let new = change.new as? String
if old != new {
print("User's full name changed to \(new ?? "nil")")
}
}
// Unregistering can be done from within the block, even in an .initial callback
_ = KVObserver(object: user, keyPath: \User.fullName, options: [.initial]) { object, _, kvo in
guard !object.fullName.isEmpty else { return }
print("User's full name is \(object.fullName)")
kvo.cancel()
}
// Or you can unregister externally
let token = KVObserver(object: user, keyPath: \User.fullName) { object, _, _ in
print("User's full name changed to \(object.fullName)")
}
// ... sometime later ...
token.cancel()
// You can also pass an observing object and KVO will be unregistered when that object deallocates
_ = KVObserver(observer: self, object: user, keyPath: \User.fullName) { observer, object, _, _ in
// `observer` has the same type as `self`
observer.nameLabel.text = object.fullName
}
Objective-C
Objective-C provides all the same functionality as Swift, albeit without the strong-typing of the observer/object.
// Observe an object for as long as the object is alive.
[PMKVObserver observeObject:self.user keyPath:@"fullName" options:0
block:^(id _Nonnull object, NSDictionary<NSKeyValueChangeKey,id> * _Nullable change, PMKVObserver * _Nonnull kvo) {
NSLog(@"User's full name changed to %@", [object fullName]);
}];
// Change dictionary is provided, but without the convenience methods.
[PMKVObserver observeObject:self.user keyPath:@"fullName"
options:NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew
block:^(id _Nonnull object, NSDictionary<NSKeyValueChangeKey,id> * _Nullable change, PMKVObserver * _Nonnull kvo) {
NSString *old = change[NSKeyValueChangeOldKey];
NSString *new = change[NSKeyValueChangeNewKey];
if (old != new && (new == nil || ![old isEqualToString:new])) {
NSLog(@"User's full name changed to %@", new);
}
}];
// Unregistering and observing object support is also provided (see Swift examples).
Requirements
Installing as a framework requires a minimum of iOS 8, OS X 10.9, watchOS 2.0, or tvOS 9.0.
If you install by copying the source into your project, it should work on iOS 7 or later (iOS 6 if you remove KVObserver.swift), and OS X 10.7 or later. Please note that it has not been tested on these versions.
PMKVObserver requires Xcode 9 or higher.
Installation
After installing with any mechanism, you can use this by adding import PMKVObserver
(Swift) or @import PMKVObserver;
(Objective-C) to your code.
Carthage
To install using Carthage, add the following to your Cartfile:
github "postmates/PMKVObserver" ~> 4.0
CocoaPods
To install using CocoaPods, add the following to your Podfile:
pod 'PMKVObserver', '~> 4.0'
Manual Installation
You may also install manually by adding the framework to your workspace, or by adding the 3 files KVObserver.h, KVObserver.m, and (optionally) KVObserver.swift to your project.
License
Licensed under either of
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.
Version History
v4.1.3 (2020-04-01)
- Work around bug with Swift compiler 5.1.5 and above relating to properties of type
Any?
(#25, SR-12486).
v4.1.2 (2019-01-24)
- Fix compatibility with Swift compiler versions other than 4.2 when observing optional values and KVO delivers an
NSNull
value.
v4.1.1 (2018-11-28)
- Add
.object
and.keyPath
properties toPMKVObserver
. The.keyPath
property is named.objcKeyPath
in Swift.
v4.1.0 (2018-11-27)
- Handle observing optional values better. We now make stronger guarantees about when
.old
and.new
are non-nil
.
v4.0.0 (2018-09-05)
- Set Swift version to 4.
- Work around Xcode 10 issue with value conversions involving
Any
in theKVObserver.Change
object (SR-8704). - Handle
RawRepresentable
types inKVObserver.Change
's.old
and.new
properties.
Note: Optional RawRepresentable
types (such as those produced by a path like \.foo?.bar
) are only supported in Swift 4.1 and later.
v3.0.2 (2018-05-22)
- Squelch some warnings when building with CocoaPods.
v3.0.1 (2017-09-13)
- Set Swift version back to Swift 3.2. The new
KeyPath
stuff is usable from 3.2 so there's no reason to require 4. PMVKObserver will still compile with Swift 3.1, but theKeyPath
APIs won't be available unless compiling with Swift 3.2.
v3.0.0 (2017-09-12)
- Convert to Swift 4.
- Add new initializers that use Swift 4
KeyPath
s. - Make
Change.rawDict
andChange.kind
non-optional.
v2.0.2 (2017-07-25)
- Switch to an unfair lock in teardown. This uses
os_unfair_lock
on platforms that support it, otherwise it uses an unfair mutex.
v2.0.1 (2016-09-15)
- Fix CocoaPods.
v2.0.0 (2016-09-08)
- Update for Swift 3.0.
v1.0.5 (2016-09-08)
- Update for Swift 2.3.
v1.0.4 (2016-03-02)
- Update CocoaPods podspec to split Swift support into a subspec.
v1.0.3 (2015-01-28)
- Add property
cancelled
toPMKVObserver
.
v1.0.2 (2016-01-26)
- Switch to dual-licensed as MIT or Apache 2.0.
v1.0.1 (2015-12-17)
- Stop leaking our
pthread_mutex_t
s.
v1.0 (2015-12-17)
Initial release.
*Note that all licence references and agreements mentioned in the PMKVObserver README section above
are relevant to that project's source code only.