Mergeable

A framework for merging objects together.

Features:

• Merge an object into an other.

When you perform a merge operation it will return an object of the same type containing only the updated properties. In the example below the result object will not contain a value for firstName since it didn't change.

var user = User(firstName: "John",
                lastName: "Apple",
                postsCount: 24)

let updateUser = User(firstName: "John",
                        lastName: "Apple Seed")

let resultUser = user.merge(with: updateUser)

print(user)           // firstName: John, lastName: Apple, postsCount: 24
print(resultUser)      // lastName: Apple Seed

• Merge an object containing nested objects into an other.

If objects contain id values you can optionally pass an idKey to merge(with: ) function to spectify how to merge unique objects together. If an object contains an array of objects the idKey will be used. In the example below we are using id as the variable name for ids in our object. The merge function will update the firstName value of friend with id: 1 and insert a second friend with id: 2. The result returned by this operation will also contain only fields that have changed after performing the merge operation.

var user = User(firstName: "Emma",
                friends: [User(id: "1", firstName: "Jo-hn")])

let updateUser = User(friends: [User(id: "1", firstName: "John"),
                                User(id: "2", firstName: "Apple")])

let resultUser = user.merge(with: updateUser, idKey: "id")

print(user)
// firstName: Emma,
// friends: [id: 1, firstName: John,
//           id: 2, firstName: Apple]

print(resultUser)
// friends: [firstName: John,
//           id: 2, firstName: Apple]

• Merge a Dictionary into an other Dictionary.

Under the hood, this library converts Codable objects into dictionary objects using JSONEncoding, and convert them back to Codable objects using JSONDecoding once merge operations are applied. For this reason, this library also spports merging a dictionary into an other dictionary in the same way.