robbiehanson/ZDCSyncable

import ZDCSyncable

struct Person: ZDCSyncable { // Just add ZDCSyncable protocol

  @Syncable var name: String // Then add @Syncable property wrapper.
  @Syncable var age: Int = 1 // And that's it!
}

// And now you get undo & redo support

let person = Person(name = "alice")
// ^ starting point

person.name = "bob"
person.age = 2
		
let changeset = person.changeset() // changes since starting point
do {
  let redo = try person.undo(changeset!) // revert to starting point

  // Current state:
  // person.name == "alice"
  // person.age == 1

  let _ = try person.undo(redo) // redo == (undo an undo)

  // Current state:
  // person.name == "bob"
  // person.age == 2
			
} catch _ {}

import ZDCSyncable

class Animal: ZDCRecord { // <- Just extend ZDCRecord

  @Syncable var species: String // And add @Syncable property wrapper.
  @Syncable var age: Int
}

import ZDCSyncable

struct Television: ZDCSyncable { // Add ZDCSyncable protocol

  @Syncable var brand: String // Add @Syncable property wrapper.
  
  // Or use syncable collection class:
  var specs = ZDCDictionary<String, String>()
  
  // ZDCDictionary has almost the exact same API as Swift's Dictionary.
  // And ZDCDictionary is a struct, so you get the same value semantics.
}

var tv = Television(brand: "Samsung")
tv.specs["size"] = "30"
tv.clearChangeTracking() // set starting point
		
tv.brand = "Sony"
tv.specs["size"] = "40"
tv.specs["widescreen"] = "true"
		
let changeset = tv.changeset() // changes since starting point
do {
  let redo = try tv.undo(changeset!) // revert to starting point
  
  // Current state:
  // tv.brand == "Samsung"
  // tv.specs["size"] == "30"
  // tv.specs["widescreen"] = nil

  let _ = try tv.undo(redo) // redo == (undo an undo)

  // Current state:
  // tv.brand == "Sony"
  // tv.specs["size"] == "40"
  // tv.specs["widescreen"] = "true"
			
} catch _ {}

var localTV = Television(brand: "Samsung")
localTV.specs["size"] = "30"
localTV.clearChangeTracking() // set starting point
		
var cloudTV = localTV // Television is a struct
var changesets: [ZDCChangeset] = []
	
// local modifications

localTV.specs["size"] = "30.5"
localTV.specs["widescreen"] = "yes"
	
changesets.append(localTV.changeset() ?? ZDCChangeset())
// ^ pending local changes (not yet pushed to cloud)

// cloud modifications

cloudTV.specs["hdmi inputs"] = "2"

// Now merge cloud version into local.
// Automatically take into account our pending local changes.

do {
  try localTV.merge(cloudVersion: cloudTV, pendingChangesets: changesets)
	
  // Merged state:
  // localTV.brand == "Samsung"
  // localTV.specs["size"] == "30.5"
  // localTV.specs["widescreen"] == "true"
  // localTV.specs["hdmi inputs"] = "2"
} catch _ {}

pod 'ZDCSyncable'

// Swift
import ZDCSyncable

{
  "local version": {
    "size": "30.5",
    "widescreen": "true"
  },
  "remote version": {
    "size": "30",
    "hdmi inputs": "2"
  }
}

{
  "local version": {
    "size": "30.5",
    "widescreen": "true"
  },
  "remote version": {
    "size": "30",
    "hdmi inputs": "2"
  },
  "local changeset": {
    "size": {
      "type": "changed",
      "previous": "30"
    },
    "widescreen": {
      "type": "added"
    }
  }
}