is a JSONPatch library for Swift featuring an ergonomic DSL. It is built on the Patchouli Core engine and uses JSONPatch lib for the patch execution.
Example:
import PatchouliJSON
// Use the DSL to construct a patch on a file's JSON content.
// This step doesn't do the actual patching!
let patchedJSONContent: PatchedJSON = Content(fileURL: someJSONFileURL) {
Add(address: "/users/-", jsonContent: "alex")
Add(address: "/users/-", jsonContent: [1, "hi", 5.0])
// note: please use `null` (and never `nil`) to represent JSON's `null`
Add(address: "/users/-", jsonContent: null)
Remove(address: "/temp/log")
Replace(address: "/user_type", jsonContent: "admin")
Move(fromAddress: "/v1/last_login", toAddress: "/v2/last_login")
Copy(fromAddress: "/v1/login_count", toAddress: "/v2/login_count")
Test(address: "/magic_string", jsonContent: "0xdeadbeef")
}
// execute the patch
let resultJSONContent: JSONContent = try content.reduced()
// Get the result in various forms
let jsonData = try dataResult.data()
let jsonString = try dataResult.string() // defaults to UTF8
let jsonStringUTF16 = try dataResult.string(encoding: utf16)
You can also fetch JSON content from bundles:
// loads User.json from the main bundle
let patchedJSONContent: PatchedJSON = Content(resource: "User", bundle: Bundle.main) {
Add(address: "/users/-", jsonContent: "alex")
...
And you can use string literals for your source json (utf8 is assumed):
let patchedJSONContent: PatchedJSON = Content(string:
"""
{ "greet": "Hello", "bye": "auf wiedersehen", "users": [] }
"""
) {
Add(address: "/users/-", jsonContent: "alex")
...
You can also use an empty JSON object or array as your starting point:
let patchedEmptyObject = EmptyJSONObject {
Add(address: "/asdf", jsonContent: "Hello")
}
let patchedEmptyArray1 = EmptyJSONArray {
Add(address: "/-", jsonContent: "xyz")
Add(address: "/-", jsonContent: "abc")
}
You can use @JSONPatchListBuilder in the same way as SwiftUI's @ViewBuilder to break up your patch declarations:
@JSONPatchListBuilder
func builderFunc(name: String) -> JSONPatchList {
Add(address: "/asdf", jsonContent: "Hello \(name)")
Add(address: "/qwer", jsonContent: "Bye \(name)")
}
@JSONPatchListBuilder
var builderVar: JSONPatchList {
Add(address: "/addr1", jsonContent: "Hello")
Add(address: "/addr2", jsonContent: "Bye")
builderFunc(name: "boo")
}
func useBuilderHelpers() throws {
let patchedJSONContent = Content(JSONPatchType.emptyObjectContent) {
builderFunc(name: "fred")
builderVar
}
This is particularly useful if you want to declare a patch list just once for use on multiple different bits of JSON.
The DSL can handle if, if-else, for, for-in, and optionals. For example:
let patchedJSONContent: PatchedJSON = Content(fileURL: someJSONFileURL) {
for index in 0...5 {
if someCheck(index) {
Add(address: "/abc", jsonContent: "\(index)")
}
if someCondition {
Add(address: "/cde", jsonContent: "\(index)")
} else {
Remove(address: "/cde")
}
}
for user in users {
Add(address: "/usernames/-", jsonContent: "\(user.username)")
}
}
The DSL can handle nesting, which means you can have patches-within-patches:
let patchedJSONContent: PatchedJSON = Content(fileURL: jsonFile1URL) {
Add(address: "/some_key", content: Content(fileURL: jsonFile2URL) {
Replace(address: "hello", jsonContent: "friend")
})
Remove(address: "/remove_me")
}
Note that with nested patching, the deepest operations are resolved first: in the above, the Replace patch is applied to the contents of JSON file 1. The result of that is then added at /some_key in the content from JSON file 2. And finally the Remove is peformed on that.
PatchouliJSON depends on Patchouli Core, a generic patching engine. You can use Pathcouli Core to make patchers for other kinds of data.