Extending target-action methods with RxSwift
class A{
func addTarget(target: Any, action: Selector)
}
Let's say I don't have class A source available (framework). How would I extend this class reactively to emit Rx events through an Observable?
I can create a class that just forwards the events through a PublishSubject, but in that case I wouldn't be creating a Reactive extension but doing it through a proxy class.
let a = A()
let del = CustomClassThatAddsItselfAsATarget(a)
del.event.subscribe( ...
instead of
let a = A()
a.rx.event.subscribe( ...
swift rx-swift reactive
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
add a comment |
class A{
func addTarget(target: Any, action: Selector)
}
Let's say I don't have class A source available (framework). How would I extend this class reactively to emit Rx events through an Observable?
I can create a class that just forwards the events through a PublishSubject, but in that case I wouldn't be creating a Reactive extension but doing it through a proxy class.
let a = A()
let del = CustomClassThatAddsItselfAsATarget(a)
del.event.subscribe( ...
instead of
let a = A()
a.rx.event.subscribe( ...
swift rx-swift reactive
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Does yourclass Aextend UIControl?
– Daniel T.
Nov 22 '18 at 2:46
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45
add a comment |
class A{
func addTarget(target: Any, action: Selector)
}
Let's say I don't have class A source available (framework). How would I extend this class reactively to emit Rx events through an Observable?
I can create a class that just forwards the events through a PublishSubject, but in that case I wouldn't be creating a Reactive extension but doing it through a proxy class.
let a = A()
let del = CustomClassThatAddsItselfAsATarget(a)
del.event.subscribe( ...
instead of
let a = A()
a.rx.event.subscribe( ...
swift rx-swift reactive
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
class A{
func addTarget(target: Any, action: Selector)
}
Let's say I don't have class A source available (framework). How would I extend this class reactively to emit Rx events through an Observable?
I can create a class that just forwards the events through a PublishSubject, but in that case I wouldn't be creating a Reactive extension but doing it through a proxy class.
let a = A()
let del = CustomClassThatAddsItselfAsATarget(a)
del.event.subscribe( ...
instead of
let a = A()
a.rx.event.subscribe( ...
swift rx-swift reactive
swift rx-swift reactive
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
asked Nov 21 '18 at 8:04
MercurialMercurial
1,60331326
1,60331326
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Does yourclass Aextend UIControl?
– Daniel T.
Nov 22 '18 at 2:46
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45
add a comment |
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Does yourclass Aextend UIControl?
– Daniel T.
Nov 22 '18 at 2:46
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Does your
class A extend UIControl?– Daniel T.
Nov 22 '18 at 2:46
Does your
class A extend UIControl?– Daniel T.
Nov 22 '18 at 2:46
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45
add a comment |
2 Answers
2
active
oldest
votes
This was a fun exploration. I patterned the below off of how UIControl is set up in RxCocoa.
In answer to your followup questions:
Which object will add itself as a target(addTarget method) to base?
You have to create a class that is designed to do that. I named it ATarget.
Who retains that object?
You make the object conform to Disposable and then it will be retained until disposed of.
extension Reactive where Base: A {
var event: Observable<A> {
return Observable.create { [weak a = self.base] observer in
guard let a = a else {
observer.on(.completed)
return Disposables.create()
}
let aTarget = ATarget(a: a, callback: { a in
observer.on(.next(a))
})
return Disposables.create(with: aTarget.dispose)
}
.takeUntil(deallocated)
}
}
class ATarget: NSObject, Disposable {
typealias Callback = (A) -> Void
let selector: Selector = #selector(ATarget.eventHandler)
weak var a: A?
var callback: Callback?
init(a: A, callback: @escaping Callback) {
self.a = a
self.callback = callback
super.init()
a.addTarget(target: self, action: selector)
}
@objc func eventHandler() {
if let callback = self.callback, let a = self.a {
callback(a)
}
}
func dispose() {
self.a?.removeTarget(target: self)
self.callback = nil
}
}
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the.takeUntil(deallocated)is there. Take until what is deallocated?
– Daniel T.
Nov 22 '18 at 16:20
add a comment |
RxCocoa and most other RxSwift-based frameworks take the following approach -
public extension Reactive where Base: TheOriginalClass {
See CKRecord+Rx or Bundle+Rx for an example of implementation.
Things get more complicated if you need to provide a proxy delegate, but this is out of scope of this question.
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53407609%2fextending-target-action-methods-with-rxswift%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
This was a fun exploration. I patterned the below off of how UIControl is set up in RxCocoa.
In answer to your followup questions:
Which object will add itself as a target(addTarget method) to base?
You have to create a class that is designed to do that. I named it ATarget.
Who retains that object?
You make the object conform to Disposable and then it will be retained until disposed of.
extension Reactive where Base: A {
var event: Observable<A> {
return Observable.create { [weak a = self.base] observer in
guard let a = a else {
observer.on(.completed)
return Disposables.create()
}
let aTarget = ATarget(a: a, callback: { a in
observer.on(.next(a))
})
return Disposables.create(with: aTarget.dispose)
}
.takeUntil(deallocated)
}
}
class ATarget: NSObject, Disposable {
typealias Callback = (A) -> Void
let selector: Selector = #selector(ATarget.eventHandler)
weak var a: A?
var callback: Callback?
init(a: A, callback: @escaping Callback) {
self.a = a
self.callback = callback
super.init()
a.addTarget(target: self, action: selector)
}
@objc func eventHandler() {
if let callback = self.callback, let a = self.a {
callback(a)
}
}
func dispose() {
self.a?.removeTarget(target: self)
self.callback = nil
}
}
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the.takeUntil(deallocated)is there. Take until what is deallocated?
– Daniel T.
Nov 22 '18 at 16:20
add a comment |
This was a fun exploration. I patterned the below off of how UIControl is set up in RxCocoa.
In answer to your followup questions:
Which object will add itself as a target(addTarget method) to base?
You have to create a class that is designed to do that. I named it ATarget.
Who retains that object?
You make the object conform to Disposable and then it will be retained until disposed of.
extension Reactive where Base: A {
var event: Observable<A> {
return Observable.create { [weak a = self.base] observer in
guard let a = a else {
observer.on(.completed)
return Disposables.create()
}
let aTarget = ATarget(a: a, callback: { a in
observer.on(.next(a))
})
return Disposables.create(with: aTarget.dispose)
}
.takeUntil(deallocated)
}
}
class ATarget: NSObject, Disposable {
typealias Callback = (A) -> Void
let selector: Selector = #selector(ATarget.eventHandler)
weak var a: A?
var callback: Callback?
init(a: A, callback: @escaping Callback) {
self.a = a
self.callback = callback
super.init()
a.addTarget(target: self, action: selector)
}
@objc func eventHandler() {
if let callback = self.callback, let a = self.a {
callback(a)
}
}
func dispose() {
self.a?.removeTarget(target: self)
self.callback = nil
}
}
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the.takeUntil(deallocated)is there. Take until what is deallocated?
– Daniel T.
Nov 22 '18 at 16:20
add a comment |
This was a fun exploration. I patterned the below off of how UIControl is set up in RxCocoa.
In answer to your followup questions:
Which object will add itself as a target(addTarget method) to base?
You have to create a class that is designed to do that. I named it ATarget.
Who retains that object?
You make the object conform to Disposable and then it will be retained until disposed of.
extension Reactive where Base: A {
var event: Observable<A> {
return Observable.create { [weak a = self.base] observer in
guard let a = a else {
observer.on(.completed)
return Disposables.create()
}
let aTarget = ATarget(a: a, callback: { a in
observer.on(.next(a))
})
return Disposables.create(with: aTarget.dispose)
}
.takeUntil(deallocated)
}
}
class ATarget: NSObject, Disposable {
typealias Callback = (A) -> Void
let selector: Selector = #selector(ATarget.eventHandler)
weak var a: A?
var callback: Callback?
init(a: A, callback: @escaping Callback) {
self.a = a
self.callback = callback
super.init()
a.addTarget(target: self, action: selector)
}
@objc func eventHandler() {
if let callback = self.callback, let a = self.a {
callback(a)
}
}
func dispose() {
self.a?.removeTarget(target: self)
self.callback = nil
}
}
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
This was a fun exploration. I patterned the below off of how UIControl is set up in RxCocoa.
In answer to your followup questions:
Which object will add itself as a target(addTarget method) to base?
You have to create a class that is designed to do that. I named it ATarget.
Who retains that object?
You make the object conform to Disposable and then it will be retained until disposed of.
extension Reactive where Base: A {
var event: Observable<A> {
return Observable.create { [weak a = self.base] observer in
guard let a = a else {
observer.on(.completed)
return Disposables.create()
}
let aTarget = ATarget(a: a, callback: { a in
observer.on(.next(a))
})
return Disposables.create(with: aTarget.dispose)
}
.takeUntil(deallocated)
}
}
class ATarget: NSObject, Disposable {
typealias Callback = (A) -> Void
let selector: Selector = #selector(ATarget.eventHandler)
weak var a: A?
var callback: Callback?
init(a: A, callback: @escaping Callback) {
self.a = a
self.callback = callback
super.init()
a.addTarget(target: self, action: selector)
}
@objc func eventHandler() {
if let callback = self.callback, let a = self.a {
callback(a)
}
}
func dispose() {
self.a?.removeTarget(target: self)
self.callback = nil
}
}
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
edited Nov 22 '18 at 14:34
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
answered Nov 22 '18 at 14:25
Daniel T.Daniel T.
13k22534
13k22534
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the.takeUntil(deallocated)is there. Take until what is deallocated?
– Daniel T.
Nov 22 '18 at 16:20
add a comment |
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the.takeUntil(deallocated)is there. Take until what is deallocated?
– Daniel T.
Nov 22 '18 at 16:20
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
Awesome, thanks. I didn't consider conforming to Disposable, that makes sense. The way I solved it is by making a ref cycle in the ATarget class to A, and then setting it to nil in Disposables.create{ } block, but I knew there must be a better way.
– Mercurial
Nov 22 '18 at 16:14
One thing I'm not sure about is why the
.takeUntil(deallocated) is there. Take until what is deallocated?– Daniel T.
Nov 22 '18 at 16:20
One thing I'm not sure about is why the
.takeUntil(deallocated) is there. Take until what is deallocated?– Daniel T.
Nov 22 '18 at 16:20
add a comment |
RxCocoa and most other RxSwift-based frameworks take the following approach -
public extension Reactive where Base: TheOriginalClass {
See CKRecord+Rx or Bundle+Rx for an example of implementation.
Things get more complicated if you need to provide a proxy delegate, but this is out of scope of this question.
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
add a comment |
RxCocoa and most other RxSwift-based frameworks take the following approach -
public extension Reactive where Base: TheOriginalClass {
See CKRecord+Rx or Bundle+Rx for an example of implementation.
Things get more complicated if you need to provide a proxy delegate, but this is out of scope of this question.
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
add a comment |
RxCocoa and most other RxSwift-based frameworks take the following approach -
public extension Reactive where Base: TheOriginalClass {
See CKRecord+Rx or Bundle+Rx for an example of implementation.
Things get more complicated if you need to provide a proxy delegate, but this is out of scope of this question.
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
RxCocoa and most other RxSwift-based frameworks take the following approach -
public extension Reactive where Base: TheOriginalClass {
See CKRecord+Rx or Bundle+Rx for an example of implementation.
Things get more complicated if you need to provide a proxy delegate, but this is out of scope of this question.
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
edited Nov 21 '18 at 11:39
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
answered Nov 21 '18 at 9:35
Maxim VolginMaxim Volgin
1,8221120
1,8221120
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53407609%2fextending-target-action-methods-with-rxswift%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Can you explain what exactly the problem is with either approach? I do not understand the context of your question.
– Maxim Volgin
Nov 21 '18 at 11:33
Let's say you create a Reactive extension where Base is the original class. Which object will add itself as a target(addTarget method) to base? Who retains that object? If you create it in the Observable.create closure, it will get deallocated as soon as the Disposable is returned. Should that class retain the observer and push directly onNext events or create a PublishSubject? I can hack something up, but I'm interested if this has already been covered before. The best solution I found so far is the implementation of ControlEvent and ControlTarget which inherits from RxTarget.
– Mercurial
Nov 21 '18 at 16:11
Does your
class Aextend UIControl?– Daniel T.
Nov 22 '18 at 2:46
@DanielT. Nope.
– Mercurial
Nov 22 '18 at 8:45