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https://github.com/voluntadpear/reswiftundo
Swift implementation of redux-undo for ReSwift for use with ReSwift
https://github.com/voluntadpear/reswiftundo
cocoapods redux redux-undo reswift swift swift-3 swift3 undo-redo
Last synced: about 1 month ago
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Swift implementation of redux-undo for ReSwift for use with ReSwift
- Host: GitHub
- URL: https://github.com/voluntadpear/reswiftundo
- Owner: voluntadpear
- License: mit
- Created: 2017-04-08T18:29:09.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2017-05-17T18:27:31.000Z (over 7 years ago)
- Last Synced: 2024-09-29T22:21:04.099Z (about 1 month ago)
- Topics: cocoapods, redux, redux-undo, reswift, swift, swift-3, swift3, undo-redo
- Language: Swift
- Size: 39.1 KB
- Stars: 6
- Watchers: 1
- Forks: 2
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
[](https://travis-ci.org/voluntadpear/ReSwiftUndo)
[](https://github.com/Carthage/Carthage)
[](https://github.com/voluntadpear/ReSwiftUndo/blob/master/LICENSE)
# ReSwiftUndo
Swift implementation of [redux-undo](https://github.com/omnidan/redux-undo) for Swift to use with [ReSwift](https://github.com/ReSwift/ReSwift) 4.0
***Work in progress***
## Use
Suppose the state of your app is like this:
```swift
struct State: StateType, Equatable {
var counter: Int = 0
static func ==(lhr: State, rhr: State) -> Bool {
return lhr.counter == rhr.counter
}
}
```
**Notice:** it's important that your State conforms to the Equatable protocol.
And your reducer looks like this:
```swift
func reducer(action: Action, state: State?) -> State {
var state = state ?? initialState()
switch action {
case _ as Increase:
state.counter = state.counter + 1
case _ as Decrease:
state.counter = state.counter - 1
default:
break
}
return state
}
```
With ReSwiftUndo you can trigger actions that lets you go back to your previous state and back to the recent one.
Wrapping your state with `undoable` makes the state look like this:
```swift
public struct UndoableState: StateType {
public var past: [T]
public var present: T
public var future: [T]
}
```
Now you can get the current state like this: `state.present`
```swift
let appReducer = undoable(reducer: reducer)
var store = Store>(reducer: appReducer, state: nil)
```
If you only need a substate of your app to be undoable you can do something like this:
```swift
func appReducer(action: Action, state: State?) -> State {
let folderUndoableReducer = undoable(reducer: foldersReducer, filter: filterCondition)
return State(
authenticationState: authenticationReducer(action: action, state: state?.authenticationState),
commonState: commonReducer(action: action, state: state?.commonState),
foldersState: folderUndoableReducer(action, state?.foldersState)
)
}
```
You can now trigger the `Undo` and `Redo` actions and do things like these:
```swift
print(store.state.present.counter) // 0
store.dispatch(Increase())
print(store.state.present.counter) // 1
print(store.state.past[0].counter) // 0
store.dispatch(Undo())
print(store.state.present.counter) // 0
print(store.state.future[0].counter) // 1
store.dispatch(Redo())
print(store.state.present.counter) // 1
```
### Filtering actions
Notice that only actions resulting in a new state are recorded. But if you want to discard some actions in the undo/redo history, or to only record history if a certain part of the state is changed you can
add a `filter` function to `undoable`.
If you want to create your own filter, pass in a function or closure with the parameters of type
`(Action, T, UndoableState)` where you receive the action dispatched, the new currentState and the previous history. For example:
```swift
let filterCondition: UndoableFilter = { (_, new, previous) in
let previousPresent = previous.present
let sameFolder = previousPresent.folder?.itemId == new.folder?.itemId
return !sameFolder
}
let folderUndoableReducer: (Action, UndoableState?) -> UndoableState =
undoable(reducer: foldersReducer, filter: filterCondition)
```
## Install
### CocoaPods
Add to your `Podfile`:
```
pod 'ReSwiftUndo'
```
Run `pod install`